diff --git a/docs/mstest-runner-protocol/004-protocol-dotnet-test-pipe.md b/docs/mstest-runner-protocol/004-protocol-dotnet-test-pipe.md
index 1839966f5e..d9bd5efabc 100644
--- a/docs/mstest-runner-protocol/004-protocol-dotnet-test-pipe.md
+++ b/docs/mstest-runner-protocol/004-protocol-dotnet-test-pipe.md
@@ -1,29 +1,10 @@
 # 004 - `dotnet test` Named-Pipe Protocol
 
 This document is the descriptive specification of the **`dotnet test` pipe protocol** (a.k.a. the
-`dotnettestcli` protocol): the small, versioned, **binary** protocol used between a
+`dotnettestcli` protocol): the small, versioned, **binary** protocol used over a named pipe between a
 Microsoft.Testing.Platform (MTP) test application and the `dotnet test` implementation shipped in the
 .NET SDK.
 
-> [!IMPORTANT]
-> **Protocol vs. transport.** The wire protocol described in this document - message shapes, serializer
-> IDs, field IDs, the handshake, versioning - is **transport-neutral**. It is defined purely in terms of a
-> duplex byte stream: whoever creates the stream, and how, is a separate concern. Two transports exist
-> today:
->
-> - **Named pipe** (`System.IO.Pipes`, §3) - the original and still-default transport, activated by
->   `--dotnet-test-pipe <name>`. Everything in §3 through §13 below describes this transport unless noted.
-> - **WebSocket** (§15) - required on runtimes that cannot open named pipes (`browser-wasm`), and optional
->   elsewhere, activated by `--dotnet-test-transport websocket` plus `--dotnet-test-websocket-endpoint`
->   and `--dotnet-test-websocket-token`.
->
-> Sections 4 ("Framing"), 5 ("Body serialization format"), 6 ("Serializer registry"), 7 ("Request/reply
-> model"), 8 ("Handshake & version negotiation"), 9 ("Message catalog"), and 10 ("Versioning &
-> compatibility") apply **identically** to both transports - they operate on "the stream", not
-> specifically "the pipe". Only §3 ("Pipe naming & transport") and §11-§12 (connection-loss and the
-> reverse control channel) describe named-pipe-specific behavior; see §15 for the WebSocket equivalents
-> and the (currently pipe-only) gaps.
-
 It is a *different* protocol from the [JSON-RPC server-mode protocol](./001-protocol-intro.md):
 
 | | JSON-RPC server mode | `dotnet test` pipe protocol (this doc) |
@@ -89,18 +70,12 @@ Rules and behavior:
 
 - `--server` accepts zero or one argument. The value `dotnettestcli` (case-insensitive) selects this
   protocol. `--server jsonrpc` (or `--server` with no value) selects JSON-RPC server mode instead.
-- `--server dotnettestcli` **requires** exactly one pre-launch transport to be fully specified: either
-  `--dotnet-test-pipe` (the default named-pipe transport, §3) or `--dotnet-test-transport websocket`
-  together with `--dotnet-test-websocket-endpoint` and `--dotnet-test-websocket-token` (§15). Specifying
-  neither, both, or an incomplete WebSocket option set fails command-line validation with an actionable
-  message (`PlatformCommandLineDotnetTestCliRequiresPipe`, `PlatformCommandLineDotnetTestTransportConflict`,
-  `PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken`, ...). Selecting the named-pipe transport
-  on a runtime that cannot open one (`browser-wasm`, `wasi-wasm`) also fails validation early instead of
-  crashing deep inside the connection bootstrap.
+- `--server dotnettestcli` **requires** `--dotnet-test-pipe`; command-line validation fails otherwise
+  (`PlatformCommandLineDotnetTestCliRequiresPipe`).
 - `--dotnet-test-pipe` takes **exactly one** argument: the fully-resolved OS pipe name/path the SDK is
   already listening on (see §3).
-- All of these options are built-in and **hidden**: the platform omits them from `--help`, so they are
-  only listed by `--info`. They are not meant for direct end-user use.
+- Both options are built-in and **hidden**: the platform omits them from `--help`, so they are only
+  listed by `--info`. They are not meant for direct end-user use.
 
 ### Environment variables
 
@@ -370,7 +345,6 @@ Property IDs (`HandshakeMessagePropertyNames`):
 | 13 | `AttemptNumber` | test host only | Positive, 1-based retry attempt. Multiple Instance IDs may share one attempt. |
 | 14 | `SupportedPostProcessorKinds` | test host, server test host, test host controller, or artifact post-processor | Semicolon-separated reverse-DNS artifact kinds supported by registered post-processors. |
 | 15 | `SupportedPostProcessorExtensionsLegacy` | test host, server test host, test host controller, or artifact post-processor | Semicolon-separated lowercase file extensions used as a fallback for untagged artifacts. |
-| 16 | `Transport` | yes | Which transport carried this handshake: `NamedPipe` or `WebSocket` (`HandshakeMessageTransportNames`). Diagnostic/negotiation-only - the wire protocol itself never varies by transport. |
 
 ### 8.2 SDK → host: `HandshakeMessage` (reply)
 
@@ -386,7 +360,7 @@ The SDK replies with its own `HandshakeMessage`. The host reads these properties
 
 ### 8.3 Negotiation algorithm
 
-The host advertises `ProtocolConstants.SupportedVersions` (currently `"1.0.0;1.1.0;1.2.0;1.3.0;1.4.0;1.5.0"`).
+The host advertises `ProtocolConstants.SupportedVersions` (currently `"1.0.0;1.1.0;1.2.0;1.3.0;1.4.0"`).
 The SDK picks the **highest version present in both sets** and returns that single value. The host then:
 
 - Confirms the returned value is in its supported set (compatibility gate).
@@ -529,7 +503,7 @@ agent.
 
 ## 10. Versioning & compatibility
 
-`SupportedVersions = "1.0.0;1.1.0;1.2.0;1.3.0;1.4.0;1.5.0"`.
+`SupportedVersions = "1.0.0;1.1.0;1.2.0;1.3.0;1.4.0"`.
 
 | Version | What it adds / signals |
 | --- | --- |
@@ -538,7 +512,6 @@ agent.
 | 1.2.0 | Adds `AzureDevOpsLogMessage` (ID 11). Host forwards ADO logging commands (only on an ADO agent). |
 | 1.3.0 | Adds `DisplayMessage` (ID 12). Host forwards warning/error host diagnostics (always). |
 | 1.4.0 | Adds the reverse **server-control** channel (`WaitForServerControlRequest` ID 13, `ServerControlMessage` ID 14). Version is bumped so negotiated state advances in lockstep, but the feature itself is gated on the `ServerControlPipeName` handshake property, not on the version. **testfx-side / pending SDK support:** the current `dotnet/sdk` advertises only `1.0.0`–`1.3.0` and does not vendor serializers 13/14, so it cannot advertise `ServerControlPipeName` or drive the channel yet. In practice the negotiated version tops out at 1.3.0 until the coordinated SDK change lands (see §12). |
-| 1.5.0 | Adds the `Transport` handshake property (ID 16), reported as `NamedPipe` or `WebSocket`. Framing and serializer formats are unchanged; older peers ignore the additive field. |
 
 Compatibility rules / assumptions:
 
@@ -689,161 +662,14 @@ own Execution ID (see §1/§2).
 | Concern | File(s) |
 | --- | --- |
 | Wire contract (IDs, field IDs) | `ServerMode/DotnetTest/IPC/ObjectFieldIds.cs` |
-| Constants (states, versions, handshake props, transport names) | `ServerMode/DotnetTest/IPC/Constants.cs` |
+| Constants (states, versions, handshake props) | `ServerMode/DotnetTest/IPC/Constants.cs` |
 | Serializer registry | `IPC/Serializers/RegisterSerializers.cs` |
 | Serializer primitives / envelope | `IPC/Serializers/BaseSerializer.cs`, `NamedPipeSerializer.cs` |
-| Shared duplex-stream framing (both transports) | `IPC/NamedPipeConnectionBase.cs` |
-| Named-pipe transport | `IPC/NamedPipeServer.cs`, `IPC/NamedPipeClient.cs` |
+| Framing / transport | `IPC/NamedPipeConnectionBase.cs`, `NamedPipeServer.cs`, `NamedPipeClient.cs` |
 | Pipe naming | `NamedPipeServer.GetPipeName` |
-| WebSocket transport | `ServerMode/DotnetTest/Transport/DotnetTestWebSocketClient.cs`, `ClientWebSocketDuplexStream.cs`, `BrowserWebSocketDuplexStream.cs` |
-| Transport selection / CLI options | `CommandLine/PlatformCommandLineProvider.cs`, `ServerMode/DotnetTest/DotnetTestHelper.cs` (`DotnetTestTransportKind`) |
 | Message models | `ServerMode/DotnetTest/IPC/Models/*.cs`, `IPC/Models/*.cs` |
 | Message serializers | `ServerMode/DotnetTest/IPC/Serializers/*.cs` |
-| Host connection / handshake / control channel / transport dispatch | `ServerMode/DotnetTest/DotnetTestConnection.cs` |
+| Host connection / handshake / control channel | `ServerMode/DotnetTest/DotnetTestConnection.cs` |
 | Host data consumer (state → message mapping) | `ServerMode/DotnetTest/IPC/DotnetTestDataConsumer.cs` |
 | Shared-source manifest (vendored to dotnet/sdk) | `ServerMode/DotnetTest/DotnetTestProtocolContract.props` |
 | Black-box protocol reference / tests | `test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DotnetTestPipe/*`, `test/UnitTests/Microsoft.Testing.Platform.DotnetTestProtocolContract.UnitTests/*` |
-
----
-
-## 15. WebSocket transport
-
-> [!NOTE]
-> This section covers the **transport bootstrap** for the WebSocket alternative to the named pipe. The
-> framing and serializer formats carried over it are exactly what §4-§10 describe. Protocol 1.5 adds the
-> optional `Transport` handshake property and advertises the new version; older peers ignore the additive
-> property, so the existing compatibility and version-negotiation model remains unchanged.
-
-### 15.1 Why a second transport exists
-
-`System.IO.Pipes` (and therefore the entire transport described in §3) is unavailable on `browser-wasm`
-(and `wasi-wasm`): there is no OS-level named-pipe primitive to open. Before this transport existed, the
-SDK had no way to run a browser-wasm test application through the live `dotnet test` pipe protocol at all
-and had to fall back to a degraded, standalone launch mode. The WebSocket transport gives `dotnet test` a
-bootstrap path that works on any runtime with a WebSocket implementation, so the *same* wire protocol
-(same serializers, same handshake, same message catalog) can be used everywhere.
-
-Protocol and transport are deliberately decoupled: `DotnetTestConnection` talks to an `IClient` (a small
-connect/request-reply abstraction implemented identically in shape by `NamedPipeClient` and
-`DotnetTestWebSocketClient`), and the shared framing in `NamedPipeConnectionBase` operates on a plain
-`Stream` rather than a `PipeStream` specifically. Only `NamedPipeClient`'s pipe-specific behavior (pipe
-naming, `WaitForPipeDrain`) stays isolated to the named-pipe implementation.
-
-### 15.2 Activation
-
-```text
-<testapp> --server dotnettestcli --dotnet-test-transport websocket \
-          --dotnet-test-websocket-endpoint <wsUri> --dotnet-test-websocket-token <token> [other options]
-```
-
-- `--dotnet-test-transport websocket` selects this transport. Omitting `--dotnet-test-transport` (or
-  passing `--dotnet-test-transport pipe`) keeps the named-pipe transport (§2, §3), which remains the
-  default for exact backward compatibility.
-- `--dotnet-test-websocket-endpoint` takes the fully-resolved `ws://` (or `wss://`) URI the SDK/gateway is
-  already listening on - the test host is always the one that *initiates* the outbound connection, exactly
-  mirroring the named-pipe transport where the SDK creates the pipe and the host connects out to it. This
-  matters specifically for `browser-wasm`: the page/test host runs inside the browser sandbox and can only
-  make outbound connections; it cannot accept inbound ones. The URI must be absolute and must not contain
-  user information or a fragment.
-- `--dotnet-test-websocket-token` takes a per-run opaque secret the SDK generated for this connection (see
-  §15.4); an empty or whitespace-only token is rejected during command-line validation.
-- All three options are hidden and built-in, like `--dotnet-test-pipe`.
-- Command-line validation (`PlatformCommandLineProvider.ValidateCommandLineOptionsAsync`) rejects
-  impossible or incomplete combinations before any connection is attempted: the named-pipe transport on
-  `browser-wasm`/`wasi-wasm`, `--dotnet-test-transport websocket` without both endpoint and token,
-  specifying both a pipe and a WebSocket transport, or WebSocket-only options without
-  `--dotnet-test-transport websocket`. `wasi-wasm` currently has **no** working transport at all (see
-  §15.6) and is rejected regardless of which transport was requested.
-
-### 15.3 Framing over WebSocket
-
-Every `NamedPipeConnectionBase.WriteMessageAsync` call writes one already-assembled frame (4-byte length +
-4-byte serializer ID + body) in a single `Stream.WriteAsync`. The WebSocket adapters
-(`ClientWebSocketDuplexStream` for non-browser runtimes, `BrowserWebSocketDuplexStream` for `browser-wasm`)
-map that 1:1 to one **binary** WebSocket message per frame (`endOfMessage: true`). Reads are treated as a
-plain byte stream - consecutive receives are handed back verbatim and buffered across calls - rather than
-relying on WebSocket message boundaries, so the adapters stay correct regardless of how a given frame is
-fragmented on the wire by the peer or an intermediary.
-
-`System.Net.WebSockets.ClientWebSocket` throws `PlatformNotSupportedException` on `browser-wasm`, so
-`browser-wasm` uses a dedicated adapter that talks to the browser's native `WebSocket` object through
-`[JSImport]` JS interop (the same pattern `OutputDevice.BrowserOutputDevice` already uses for
-`console.*`). The companion JS module is embedded as a string constant and imported via a `data:` URL, so
-no changes to the generated wasm bootstrap or published asset set are required.
-
-> [!NOTE]
-> **CSP caveat.** The `data:` URL dynamic import relies on the page's Content-Security-Policy permitting it.
-> A strict `script-src` that omits `data:` (and lacks `'unsafe-inline'`/a matching `'nonce-'`/`'sha256-'`
-> hash for the embedded module, or `'strict-dynamic'`) will block the import, and the WebSocket transport will
-> fail to initialize on that page. This is a real constraint under a locked-down CSP, not merely a theoretical
-> one - "no additional assets are required" (above) is true for the wasm bootstrap/publish output, but it is
-> not the same as "works under any CSP". A future revision could ship the module as a conventional `.js` asset
-> (with a `nonce`/hash-friendly `<script>` tag) instead of a `data:` import if this becomes a blocker for a
-> real deployment; that is a follow-up, not something this document should currently claim to solve.
-
-### 15.4 Authentication and security
-
-There is no OS-level ACL equivalent to `PipeOptions.CurrentUserOnly` for a TCP/WebSocket endpoint, so the
-transport authenticates every connection explicitly:
-
-- The SDK generates a per-run opaque token and passes it via `--dotnet-test-websocket-token`.
-- The test host appends it to the connection URI as a query-string parameter (e.g.
-  `?dotnetTestToken=<token>`) before connecting - see `DotnetTestWebSocketClient.BuildAuthenticatedUri`.
-  This is deliberate, not a workaround: the browser's native `WebSocket` constructor only accepts a URL and
-  an optional subprotocol list, so it **cannot** set an `Authorization` header (or any other custom
-  header) on the upgrade handshake. A query-string token is the same approach ASP.NET Core SignalR uses
-  for its WebSocket transport for the identical reason.
-- **CORS is not authentication and must not be relied on as one.** CORS governs which browser *origins* may
-  *read* a cross-origin response; it says nothing about which *process* may *open* a WebSocket connection
-  to a loopback port in the first place. Any local process that can reach the port can attempt the
-  handshake, so the token is the actual access check, not a defense-in-depth extra.
-- The SDK is expected to bind the listener to loopback (`127.0.0.1`/`::1`) only and to reject connections
-  whose token does not match the one it generated for that run/endpoint.
-- **Never log the authenticated URI (or the token) verbatim.** Diagnostics should log only the endpoint's
-  host/port/path, never the query string. This is enforced for the platform's own `--diagnostic` log too:
-  the "Command line arguments" line masks the value of `--dotnet-test-websocket-token` (in both its
-  space-separated and `--option=value`/`--option:value` inline forms) via
-  `CommandLineArgumentsRedactor.Redact`, so simply enabling verbose diagnostics can never write the secret to
-  disk. Any future option that carries a secret should be added to that redactor's sensitive-option list
-  rather than relying on callers to remember to mask it themselves.
-
-### 15.5 Handshake capability signal
-
-The handshake (§8) gained one additive property, `Transport` (ID 16, `HandshakeMessagePropertyNames.Transport`),
-always sent by the host as `NamedPipe` or `WebSocket` (`HandshakeMessageTransportNames`). It exists purely
-for diagnostics and future negotiation - the wire protocol itself is identical either way - so an older SDK
-that does not look at it is entirely unaffected. `ProtocolConstants.SupportedVersions` was bumped to
-include `1.5.0` alongside it, following the same convention as every other additive capability in §10.
-
-### 15.6 Known gaps and follow-ups (out of scope here)
-
-- **Reverse server-control channel (§12) is named-pipe-only.** The SDK advertises
-  `ServerControlPipeName` as a plain OS pipe name regardless of which transport carried the handshake.
-  `DotnetTestConnection` only opens the reverse channel when the current runtime supports named pipes, so
-  on `browser-wasm` (and `wasi-wasm`) server-initiated cancellation (`--timeout`,
-  `--maximum-failed-tests`, ...) simply stays disabled - the same graceful degradation already used when an
-  older SDK never advertises the pipe at all. A WebSocket-based (or transport-agnostic) reverse control
-  channel is a natural follow-up.
-- **`wasi-wasm` has no transport yet.** It cannot use named pipes (no `System.IO.Pipes` support) and, as of
-  this writing, has neither a working `System.Net.WebSockets.ClientWebSocket` implementation nor an
-  established JS-interop equivalent in this repo (unlike `browser-wasm`, `wasi-wasm` has no browser/JS host
-  to interop with in the first place). Command-line validation rejects both transports on `wasi-wasm`
-  outright with an actionable error rather than silently falling back to a degraded mode. A `wasi-wasm`
-  transport (e.g. once/if a WASI sockets story matures in the .NET runtime) is a separate follow-up.
-- **stdio was considered and deliberately not implemented.** Multiplexing the binary dotnettestcli protocol
-  onto the same stdio streams a test host also uses for its own console output (and that other extensions
-  may write to) would require either a second framing layer on top of the existing one or careful
-  interleaving that risks corrupting either stream. Rather than ship that as a bolted-on special case, it
-  is left as a candidate for a future, separately-designed transport if a concrete need arises.
-- **The SDK side of this transport (loopback listener/gateway, token generation and validation) is not part
-  of this repository.** This document only specifies what the MTP-side client requires from that gateway;
-  see the coordinating `dotnet/sdk` change for the server implementation. When the SDK launches a
-  `browser-wasm` bundle under Node 20, it must also pass `--experimental-websocket` to Node so the embedded
-  browser adapter can use Node's built-in WebSocket implementation without adding an npm dependency. Real
-  browsers and newer Node versions where `WebSocket` is enabled by default need no extra bootstrap.
-- **The SDK gateway remains external, but the browser client is behaviorally covered in this repository.**
-  `BrowserWasmExecutionTests` publishes and runs the real `browser-wasm` client under Node against a
-  test-local loopback WebSocket gateway. The tests cover authenticated connect, binary request/reply traffic,
-  the emitted `Transport=WebSocket` handshake property, disconnect, cancellation while the HTTP upgrade is
-  stalled, cancellation of a pending receive without losing the next message, and pre-cancelled writes. This
-  validates the `[JSImport]` path on its target runtime without depending on the production SDK gateway.
diff --git a/src/Platform/Microsoft.Testing.Extensions.HangDump/InternalAPI/InternalAPI.Unshipped.txt b/src/Platform/Microsoft.Testing.Extensions.HangDump/InternalAPI/InternalAPI.Unshipped.txt
index 2f3a730906..c6f7c220b8 100644
--- a/src/Platform/Microsoft.Testing.Extensions.HangDump/InternalAPI/InternalAPI.Unshipped.txt
+++ b/src/Platform/Microsoft.Testing.Extensions.HangDump/InternalAPI/InternalAPI.Unshipped.txt
@@ -16,7 +16,3 @@ static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.WriteExecutionS
 static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.WriteListPayload<T>(System.IO.Stream! stream, ushort fieldId, T[]? list, System.Action<System.IO.Stream!, T>! writeItem) -> void
 const Microsoft.Testing.Platform.IPC.FailedTestResultMessageFieldsId.Expected = 10 -> ushort
 const Microsoft.Testing.Platform.IPC.FailedTestResultMessageFieldsId.Actual = 11 -> ushort
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Stream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Stream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Pipes.PipeStream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Pipes.PipeStream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
diff --git a/src/Platform/Microsoft.Testing.Extensions.MSBuild/InternalAPI.Unshipped.txt b/src/Platform/Microsoft.Testing.Extensions.MSBuild/InternalAPI.Unshipped.txt
index a9df34f648..ba4dc608ba 100644
--- a/src/Platform/Microsoft.Testing.Extensions.MSBuild/InternalAPI.Unshipped.txt
+++ b/src/Platform/Microsoft.Testing.Extensions.MSBuild/InternalAPI.Unshipped.txt
@@ -15,7 +15,3 @@ static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.WriteExecutionS
 static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.WriteListPayload<T>(System.IO.Stream! stream, ushort fieldId, T[]? list, System.Action<System.IO.Stream!, T>! writeItem) -> void
 const Microsoft.Testing.Platform.IPC.FailedTestResultMessageFieldsId.Expected = 10 -> ushort
 const Microsoft.Testing.Platform.IPC.FailedTestResultMessageFieldsId.Actual = 11 -> ushort
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Stream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Stream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Pipes.PipeStream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Pipes.PipeStream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
diff --git a/src/Platform/Microsoft.Testing.Extensions.Retry/InternalAPI/InternalAPI.Unshipped.txt b/src/Platform/Microsoft.Testing.Extensions.Retry/InternalAPI/InternalAPI.Unshipped.txt
index 4a4f299169..1ccd1b965a 100644
--- a/src/Platform/Microsoft.Testing.Extensions.Retry/InternalAPI/InternalAPI.Unshipped.txt
+++ b/src/Platform/Microsoft.Testing.Extensions.Retry/InternalAPI/InternalAPI.Unshipped.txt
@@ -19,7 +19,3 @@ static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.WriteExecutionS
 static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.WriteListPayload<T>(System.IO.Stream! stream, ushort fieldId, T[]? list, System.Action<System.IO.Stream!, T>! writeItem) -> void
 const Microsoft.Testing.Platform.IPC.FailedTestResultMessageFieldsId.Expected = 10 -> ushort
 const Microsoft.Testing.Platform.IPC.FailedTestResultMessageFieldsId.Actual = 11 -> ushort
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Stream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Stream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Pipes.PipeStream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Pipes.PipeStream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
diff --git a/src/Platform/Microsoft.Testing.Extensions.TrxReport/InternalAPI/InternalAPI.Unshipped.txt b/src/Platform/Microsoft.Testing.Extensions.TrxReport/InternalAPI/InternalAPI.Unshipped.txt
index 2d3d21498e..524455f5eb 100644
--- a/src/Platform/Microsoft.Testing.Extensions.TrxReport/InternalAPI/InternalAPI.Unshipped.txt
+++ b/src/Platform/Microsoft.Testing.Extensions.TrxReport/InternalAPI/InternalAPI.Unshipped.txt
@@ -69,7 +69,3 @@ Microsoft.Testing.Extensions.MergeOutputFileHelper
 static Microsoft.Testing.Extensions.MergeOutputFileHelper.BuildCaseFoldedProbePath(string! directory, string! probeFileName) -> string!
 static Microsoft.Testing.Extensions.MergeOutputFileHelper.EnsureOutputDoesNotAliasInput(System.Collections.Generic.IReadOnlyList<string!>! inputPaths, string! outputPath) -> void
 static Microsoft.Testing.Extensions.MergeOutputFileHelper.WriteViaTemporarySiblingAsync(string! outputPath, System.Func<string!, System.Threading.Tasks.Task!>! writeToTempAsync) -> System.Threading.Tasks.Task!
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Stream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Stream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Pipes.PipeStream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Pipes.PipeStream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
diff --git a/src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs b/src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs
index 6658e72576..c58fc6b5d4 100644
--- a/src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs
+++ b/src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs
@@ -186,7 +186,7 @@ private static async Task LogInformationAsync(
 
         string moduleName = testApplicationModuleInfo.GetDisplayName();
         await logger.LogInformationAsync($"Test module: {moduleName}").ConfigureAwait(false);
-        await logger.LogInformationAsync($"Command line arguments: '{CommandLineArgumentsRedactor.Redact(args)}'").ConfigureAwait(false);
+        await logger.LogInformationAsync($"Command line arguments: '{(args.Length == 0 ? string.Empty : args.Aggregate((a, b) => $"{a} {b}"))}'").ConfigureAwait(false);
 
         StringBuilder machineInfo = new();
 #pragma warning disable RS0030 // Do not use banned APIs
diff --git a/src/Platform/Microsoft.Testing.Platform/CommandLine/CommandLineArgumentsRedactor.cs b/src/Platform/Microsoft.Testing.Platform/CommandLine/CommandLineArgumentsRedactor.cs
deleted file mode 100644
index dd561a834d..0000000000
--- a/src/Platform/Microsoft.Testing.Platform/CommandLine/CommandLineArgumentsRedactor.cs
+++ /dev/null
@@ -1,228 +0,0 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-namespace Microsoft.Testing.Platform.CommandLine;
-
-/// <summary>
-/// Formats raw command-line arguments for diagnostics (e.g. the "Command line arguments" line written to the
-/// <c>--diagnostic</c> log) while masking the value(s) of options that carry secrets, so enabling verbose
-/// diagnostics never writes a secret to disk. WebSocket endpoint values are also reduced to scheme, host,
-/// port, and path so user-info, query parameters, and fragments cannot leak credentials. See
-/// <c>docs/mstest-runner-protocol/004-protocol-dotnet-test-pipe.md</c> §15.4: the
-/// <c>--dotnet-test-websocket-token</c> value is a per-run authentication secret and must never be logged.
-/// </summary>
-internal static class CommandLineArgumentsRedactor
-{
-    private const string RedactedPlaceholder = "***REDACTED***";
-
-    // Option names (without leading dashes) whose argument value(s) must never appear in diagnostics output.
-    // Extend this set - not the call site - whenever a new option is introduced that carries a secret.
-    private static readonly string[] SensitiveOptionNames =
-    [
-        PlatformCommandLineProvider.DotNetTestWebSocketTokenOptionKey,
-    ];
-
-    /// <summary>
-    /// Formats <paramref name="args"/> as a single space-separated string suitable for diagnostics, replacing
-    /// the value(s) of any option in <see cref="SensitiveOptionNames"/> with a fixed placeholder. Every other
-    /// argument - including the sensitive option's own name/prefix/delimiter - is preserved exactly except for
-    /// the sanitized WebSocket endpoint, so the output remains useful for troubleshooting.
-    /// </summary>
-    /// <remarks>
-    /// Mirrors <see cref="CommandLineParser"/>'s own option-detection rule (a token starting with a single '-'
-    /// followed by a non-'-' character, or '--' followed by a non-'-' character, optionally with an inline
-    /// '='/':' delimited value) so this stays in sync with how the real parser identifies option boundaries.
-    /// Handles a missing value (the sensitive option is the last argument - nothing follows to redact, no
-    /// out-of-range access) and a repeated option (each occurrence's value(s) are independently redacted).
-    /// </remarks>
-    public static string Redact(string[] args)
-        => string.Join(" ", RedactArguments(args));
-
-    internal static string RedactError(string error, IReadOnlyList<string> args)
-    {
-        string[] arguments = [.. args];
-        string[] redactedArguments = RedactArguments(arguments);
-        for (int i = 0; i < arguments.Length; i++)
-        {
-            string original = arguments[i];
-            string redacted = redactedArguments[i];
-            if (original == redacted)
-            {
-                continue;
-            }
-
-            if (redacted == RedactedPlaceholder)
-            {
-                if (RoslynString.IsNullOrWhiteSpace(original))
-                {
-                    continue;
-                }
-
-                error = ReplaceQuotedValue(error, original, RedactedPlaceholder);
-                string trimmedOriginal = original.Trim();
-                if (trimmedOriginal != original)
-                {
-                    error = ReplaceQuotedValue(error, trimmedOriginal, RedactedPlaceholder);
-                }
-
-                string optionNameWithoutPrefix = trimmedOriginal.TrimStart('-');
-                if (optionNameWithoutPrefix.Length > 0)
-                {
-                    error = ReplaceQuotedValue(error, optionNameWithoutPrefix, RedactedPlaceholder);
-                    error = error.Replace($"'--{optionNameWithoutPrefix}'", $"'{RedactedPlaceholder}'");
-                    error = error.Replace($"'-{optionNameWithoutPrefix}'", $"'{RedactedPlaceholder}'");
-                }
-            }
-            else if (redacted.Contains(RedactedPlaceholder))
-            {
-                int delimiterIndex = original.IndexOfAny(['=', ':']);
-                if (delimiterIndex >= 0 && delimiterIndex + 1 < original.Length)
-                {
-                    error = error.Replace(original[(delimiterIndex + 1)..], RedactedPlaceholder);
-                }
-            }
-            else
-            {
-                error = error.Replace(original, redacted);
-            }
-        }
-
-        return error;
-    }
-
-    private static string ReplaceQuotedValue(string text, string value, string replacement)
-    {
-        text = text
-            .Replace($"'{value}'", $"'{replacement}'")
-            .Replace($"\"{value}\"", $"\"{replacement}\"");
-        return value.IndexOfAny(['\'', '"']) >= 0
-            ? text.Replace(value, replacement)
-            : text;
-    }
-
-    private static string[] RedactArguments(string[] args)
-    {
-        string[] redacted = new string[args.Length];
-        bool redactingValuesForCurrentOption = false;
-        bool redactedValueForCurrentOption = false;
-        bool sanitizingEndpointValue = false;
-
-        for (int i = 0; i < args.Length; i++)
-        {
-            string arg = args[i];
-
-            if (TryParseOption(arg, out string? prefix, out string? optionName, out string? delimiter, out string? inlineValue))
-            {
-                sanitizingEndpointValue = false;
-                bool isSensitive = IsSensitiveOptionName(optionName);
-                if (redactingValuesForCurrentOption
-                    && !redactedValueForCurrentOption
-                    && !isSensitive
-                    && !IsWebSocketEndpointOptionName(optionName))
-                {
-                    // An opaque secret may itself look like an option (for example "-secret"). Diagnostic
-                    // logging happens before arity validation, so mask this token rather than leaking it.
-                    redacted[i] = RedactedPlaceholder;
-                    redactingValuesForCurrentOption = false;
-                    redactedValueForCurrentOption = true;
-                    continue;
-                }
-
-                if (isSensitive && inlineValue is not null)
-                {
-                    // Inline form, e.g. '--dotnet-test-websocket-token=<secret>': redact just the value,
-                    // preserving the original prefix/name/delimiter exactly.
-                    redacted[i] = $"{prefix}{optionName}{delimiter}{RedactedPlaceholder}";
-                    redactingValuesForCurrentOption = true;
-                    redactedValueForCurrentOption = true;
-                }
-                else if (IsWebSocketEndpointOptionName(optionName))
-                {
-                    redacted[i] = inlineValue is null
-                        ? arg
-                        : $"{prefix}{optionName}{delimiter}{SanitizeWebSocketEndpoint(inlineValue)}";
-                    redactingValuesForCurrentOption = false;
-                    redactedValueForCurrentOption = false;
-                    sanitizingEndpointValue = true;
-                }
-                else
-                {
-                    // Bare option name (no inline value): keep it as-is. If it is sensitive, its value(s) are
-                    // one or more separate following tokens - redact those below until the next option.
-                    redacted[i] = arg;
-                    redactingValuesForCurrentOption = isSensitive;
-                    redactedValueForCurrentOption = false;
-                }
-
-                continue;
-            }
-
-            if (sanitizingEndpointValue)
-            {
-                redacted[i] = SanitizeWebSocketEndpoint(arg);
-                continue;
-            }
-
-            // Not an option-looking token: it's an argument value for whichever option preceded it.
-            redacted[i] = redactingValuesForCurrentOption ? RedactedPlaceholder : arg;
-            redactedValueForCurrentOption |= redactingValuesForCurrentOption;
-        }
-
-        return redacted;
-    }
-
-    private static bool TryParseOption(string arg, [NotNullWhen(true)] out string? prefix, [NotNullWhen(true)] out string? optionName, out string? delimiter, out string? inlineValue)
-    {
-        prefix = null;
-        optionName = null;
-        delimiter = null;
-        inlineValue = null;
-
-        bool isDoubleDash = arg.Length > 2 && arg[0] == '-' && arg[1] == '-' && arg[2] != '-';
-        bool isSingleDash = !isDoubleDash && arg.Length > 1 && arg[0] == '-' && arg[1] != '-';
-        if (!isDoubleDash && !isSingleDash)
-        {
-            return false;
-        }
-
-        prefix = isDoubleDash ? "--" : "-";
-        string withoutPrefix = arg[prefix.Length..];
-
-        int delimiterIndex = withoutPrefix.IndexOfAny(['=', ':']);
-        if (delimiterIndex == -1)
-        {
-            optionName = withoutPrefix;
-            return true;
-        }
-
-        optionName = withoutPrefix[..delimiterIndex];
-        delimiter = withoutPrefix[delimiterIndex].ToString();
-        inlineValue = withoutPrefix[(delimiterIndex + 1)..];
-        return true;
-    }
-
-    private static bool IsSensitiveOptionName(string optionName)
-        => SensitiveOptionNames.Any(sensitive => sensitive.Equals(optionName, StringComparison.OrdinalIgnoreCase));
-
-    private static bool IsWebSocketEndpointOptionName(string optionName)
-        => PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey.Equals(optionName, StringComparison.OrdinalIgnoreCase);
-
-    private static string SanitizeWebSocketEndpoint(string endpoint)
-    {
-        if (!Uri.TryCreate(endpoint, UriKind.Absolute, out Uri? uri)
-            || uri.Scheme is not ("ws" or "wss"))
-        {
-            return RedactedPlaceholder;
-        }
-
-        UriBuilder builder = new(uri)
-        {
-            UserName = string.Empty,
-            Password = string.Empty,
-            Query = string.Empty,
-            Fragment = string.Empty,
-        };
-
-        return builder.Uri.AbsoluteUri;
-    }
-}
diff --git a/src/Platform/Microsoft.Testing.Platform/CommandLine/CommandLineOptionsValidator.Helpers.cs b/src/Platform/Microsoft.Testing.Platform/CommandLine/CommandLineOptionsValidator.Helpers.cs
index 5d4caff8ad..3ab2339df8 100644
--- a/src/Platform/Microsoft.Testing.Platform/CommandLine/CommandLineOptionsValidator.Helpers.cs
+++ b/src/Platform/Microsoft.Testing.Platform/CommandLine/CommandLineOptionsValidator.Helpers.cs
@@ -24,7 +24,6 @@ private static ValidationResult AddCommandLine(CommandLineParseResult parseResul
 
     private static ValidationResult InvalidWithCommandLine(CommandLineParseResult parseResult, string errorMessage)
     {
-        errorMessage = parseResult.RedactError(errorMessage);
         if (parseResult.CommandLine.Length == 0)
         {
             return ValidationResult.Invalid(errorMessage);
diff --git a/src/Platform/Microsoft.Testing.Platform/CommandLine/ParseResult.cs b/src/Platform/Microsoft.Testing.Platform/CommandLine/ParseResult.cs
index b80b84893c..6921b21b3e 100644
--- a/src/Platform/Microsoft.Testing.Platform/CommandLine/ParseResult.cs
+++ b/src/Platform/Microsoft.Testing.Platform/CommandLine/ParseResult.cs
@@ -9,8 +9,6 @@ namespace Microsoft.Testing.Platform.CommandLine;
 [Experimental("TPEXP", UrlFormat = "https://aka.ms/testingplatform/diagnostics#{0}")]
 public sealed class CommandLineParseResult : IEquatable<CommandLineParseResult>
 {
-    private readonly IReadOnlyList<string> _arguments;
-
     /// <summary>
     /// The prefix for options.
     /// </summary>
@@ -33,22 +31,11 @@ public CommandLineParseResult(string? toolName, IReadOnlyList<CommandLineParseOp
     }
 
     internal CommandLineParseResult(string? toolName, IReadOnlyList<CommandLineParseOption> options, IReadOnlyList<string> errors, IReadOnlyList<string> arguments)
-        : this(toolName, options, errors, arguments, arguments)
-    {
-    }
-
-    internal CommandLineParseResult(
-        string? toolName,
-        IReadOnlyList<CommandLineParseOption> options,
-        IReadOnlyList<string> errors,
-        IReadOnlyList<string> arguments,
-        IReadOnlyList<string> expandedArguments)
     {
         ToolName = toolName;
         Options = options;
-        _arguments = expandedArguments;
-        Errors = errors.Select(RedactError).ToArray();
-        CommandLine = CommandLineArgumentsRedactor.Redact([.. arguments]);
+        Errors = errors;
+        CommandLine = string.Join(" ", arguments);
     }
 
     /// <summary>
@@ -68,8 +55,6 @@ internal CommandLineParseResult(
 
     internal string CommandLine { get; }
 
-    internal string RedactError(string error) => CommandLineArgumentsRedactor.RedactError(error, _arguments);
-
     /// <summary>
     /// Gets a value indicating whether the parsing has errors.
     /// </summary>
diff --git a/src/Platform/Microsoft.Testing.Platform/CommandLine/Parser.cs b/src/Platform/Microsoft.Testing.Platform/CommandLine/Parser.cs
index 2918f1b178..f4c728b247 100644
--- a/src/Platform/Microsoft.Testing.Platform/CommandLine/Parser.cs
+++ b/src/Platform/Microsoft.Testing.Platform/CommandLine/Parser.cs
@@ -101,7 +101,7 @@ private static CommandLineParseResult Parse(List<string> args, IEnvironment envi
             options.Add(new(currentOption, [.. currentOptionArguments]));
         }
 
-        return new CommandLineParseResult(toolName, options, errors, originalArgs, args);
+        return new CommandLineParseResult(toolName, options, errors, originalArgs);
 
         static void ParseOptionAndSeparators(string arg, out string? currentOption, out string? currentArg)
         {
diff --git a/src/Platform/Microsoft.Testing.Platform/CommandLine/PlatformCommandLineProvider.cs b/src/Platform/Microsoft.Testing.Platform/CommandLine/PlatformCommandLineProvider.cs
index 6b5046586d..2306aae0dd 100644
--- a/src/Platform/Microsoft.Testing.Platform/CommandLine/PlatformCommandLineProvider.cs
+++ b/src/Platform/Microsoft.Testing.Platform/CommandLine/PlatformCommandLineProvider.cs
@@ -27,7 +27,6 @@ internal sealed class PlatformCommandLineProvider : CommandLineOptionsProviderBa
 
     private static readonly string SupportedDiscoverTestsValues = $"'{DiscoverTestsTextArgument}', '{DiscoverTestsJsonArgument}'";
     private static readonly string SupportedServerProtocolValues = $"'{JsonRpcProtocolName}', '{DotnetTestCliProtocolName}'";
-    private static readonly string SupportedDotNetTestTransportValues = $"'{DotNetTestTransportPipeArgument}', '{DotNetTestTransportWebSocketArgument}'";
     public const string ResultDirectoryOptionKey = "results-directory";
     public const string IgnoreExitCodeOptionKey = "ignore-exit-code";
     public const string MinimumExpectedTestsOptionKey = "minimum-expected-tests";
@@ -47,20 +46,6 @@ internal sealed class PlatformCommandLineProvider : CommandLineOptionsProviderBa
     public const string DotNetTestPipeOptionKey = "dotnet-test-pipe";
     public const string DotnetTestCliProtocolName = "dotnettestcli";
 
-    // Pre-launch transport selection for the 'dotnet test' pipe protocol (a.k.a. dotnettestcli). The wire
-    // protocol (message/serializer/version contract) is transport-neutral; this option only selects which
-    // duplex channel carries it. 'pipe' (the default, implied when only '--dotnet-test-pipe' is given) keeps
-    // the existing System.IO.Pipes behavior byte-for-byte. 'websocket' is required on runtimes that cannot use
-    // named pipes (browser-wasm) and is opt-in elsewhere.
-    public const string DotNetTestTransportOptionKey = "dotnet-test-transport";
-    public const string DotNetTestTransportPipeArgument = "pipe";
-    public const string DotNetTestTransportWebSocketArgument = "websocket";
-
-    // WebSocket-transport-specific endpoint/auth options. Both are required together with
-    // '--dotnet-test-transport websocket' and mutually exclusive with '--dotnet-test-pipe'.
-    public const string DotNetTestWebSocketEndpointOptionKey = "dotnet-test-websocket-endpoint";
-    public const string DotNetTestWebSocketTokenOptionKey = "dotnet-test-websocket-token";
-
     private static readonly string[] VerbosityOptions = ["Trace", "Debug", "Information", "Warning", "Error", "Critical"];
 
     private static readonly string SupportedZeroTestsPolicyValues = $"'{ZeroTestsPolicyStrictArgument}', '{ZeroTestsPolicyAllowSkippedArgument}'";
@@ -96,10 +81,7 @@ internal sealed class PlatformCommandLineProvider : CommandLineOptionsProviderBa
         new(SkipBuildersNumberCheckOptionKey, PlatformResources.PlatformCommandLineSkipBuildersNumberCheckOptionDescription, ArgumentArity.Zero, true, isBuiltIn: true),
         new(NoBannerOptionKey, PlatformResources.PlatformCommandLineNoBannerOptionDescription, ArgumentArity.ZeroOrOne, true, isBuiltIn: true),
         new(TestHostControllerPIDOptionKey, PlatformResources.PlatformCommandLineTestHostControllerPIDOptionDescription, ArgumentArity.ZeroOrOne, true, isBuiltIn: true),
-        new(DotNetTestPipeOptionKey, PlatformResources.PlatformCommandLineDotnetTestPipe, ArgumentArity.ExactlyOne, true, isBuiltIn: true),
-        new(DotNetTestTransportOptionKey, PlatformResources.PlatformCommandLineDotnetTestTransportOptionDescription, ArgumentArity.ExactlyOne, true, isBuiltIn: true),
-        new(DotNetTestWebSocketEndpointOptionKey, PlatformResources.PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription, ArgumentArity.ExactlyOne, true, isBuiltIn: true),
-        new(DotNetTestWebSocketTokenOptionKey, PlatformResources.PlatformCommandLineDotnetTestWebSocketTokenOptionDescription, ArgumentArity.ExactlyOne, true, isBuiltIn: true),
+        new(DotNetTestPipeOptionKey, PlatformResources.PlatformCommandLineDotnetTestPipe, ArgumentArity.ExactlyOne, true, isBuiltIn: true)
     ];
 
     public PlatformCommandLineProvider()
@@ -139,32 +121,6 @@ public override Task<ValidationResult> ValidateOptionArgumentsAsync(CommandLineO
             return ValidationResult.InvalidTask(string.Format(CultureInfo.InvariantCulture, PlatformResources.PlatformCommandLineServerInvalidArgument, arguments[0], SupportedServerProtocolValues));
         }
 
-        if (commandOption.Name == DotNetTestTransportOptionKey
-            && arguments.Length == 1
-            && !DotNetTestTransportPipeArgument.Equals(arguments[0], StringComparison.OrdinalIgnoreCase)
-            && !DotNetTestTransportWebSocketArgument.Equals(arguments[0], StringComparison.OrdinalIgnoreCase))
-        {
-            return ValidationResult.InvalidTask(string.Format(CultureInfo.InvariantCulture, PlatformResources.PlatformCommandLineDotnetTestTransportInvalidArgument, arguments[0], SupportedDotNetTestTransportValues));
-        }
-
-        if (commandOption.Name == DotNetTestWebSocketEndpointOptionKey
-            && arguments is [string endpoint]
-            && (!Uri.TryCreate(endpoint, UriKind.Absolute, out Uri? endpointUri)
-                || endpointUri.Scheme is not ("ws" or "wss")
-                || RoslynString.IsNullOrEmpty(endpointUri.Host)
-                || !RoslynString.IsNullOrEmpty(endpointUri.Fragment)
-                || !RoslynString.IsNullOrEmpty(endpointUri.UserInfo)))
-        {
-            return ValidationResult.InvalidTask(PlatformResources.PlatformCommandLineDotnetTestWebSocketEndpointInvalid);
-        }
-
-        if (commandOption.Name == DotNetTestWebSocketTokenOptionKey
-            && arguments is [string token]
-            && RoslynString.IsNullOrWhiteSpace(token))
-        {
-            return ValidationResult.InvalidTask(PlatformResources.PlatformCommandLineDotnetTestWebSocketTokenEmpty);
-        }
-
         if (commandOption.Name == ClientPortOptionKey
             && (!int.TryParse(arguments[0], NumberStyles.Integer, CultureInfo.InvariantCulture, out int port)
                 || port < System.Net.IPEndPoint.MinPort
@@ -278,84 +234,16 @@ public override Task<ValidationResult> ValidateCommandLineOptionsAsync(ICommandL
             return ValidationResult.InvalidTask(PlatformResources.OnlyOneFilterSupported);
         }
 
-        // The '--server dotnettestcli' protocol path requires exactly one pre-launch transport to carry the
-        // (transport-neutral) wire protocol: either the legacy named pipe ('--dotnet-test-pipe', the default,
-        // implied whenever it alone is given) or an explicit WebSocket transport ('--dotnet-test-transport
-        // websocket' plus its endpoint/token). Without one of these, the dotnet test connection silently never
-        // activates and the application falls back to console mode, leading to confusing behavior. All of these
-        // options are internal and are expected to be passed together by 'dotnet test'.
-        bool isDotnetTestCliServer = commandLineOptions.TryGetOptionArgumentList(ServerOptionKey, out string[]? serverProtocolArgs)
+        // The '--server dotnettestcli' protocol path requires '--dotnet-test-pipe' to connect to the
+        // dotnet test pipe. Without it, the dotnet test connection silently never activates and the
+        // application falls back to console mode, leading to confusing behavior. Both options are
+        // internal and are expected to be passed together by 'dotnet test'.
+        if (commandLineOptions.TryGetOptionArgumentList(ServerOptionKey, out string[]? serverProtocolArgs)
             && serverProtocolArgs is { Length: 1 }
-            && DotnetTestCliProtocolName.Equals(serverProtocolArgs[0], StringComparison.OrdinalIgnoreCase);
-        bool hasPipe = commandLineOptions.IsOptionSet(DotNetTestPipeOptionKey);
-        bool hasTransportOption = commandLineOptions.TryGetOptionArgumentList(DotNetTestTransportOptionKey, out string[]? transportArgs)
-            && transportArgs is { Length: 1 };
-        bool isWebSocketTransport = hasTransportOption && DotNetTestTransportWebSocketArgument.Equals(transportArgs![0], StringComparison.OrdinalIgnoreCase);
-        bool isPipeTransport = hasTransportOption && DotNetTestTransportPipeArgument.Equals(transportArgs![0], StringComparison.OrdinalIgnoreCase);
-        bool hasEndpoint = commandLineOptions.IsOptionSet(DotNetTestWebSocketEndpointOptionKey);
-        bool hasToken = commandLineOptions.IsOptionSet(DotNetTestWebSocketTokenOptionKey);
-        bool hasDotnetTestTransportOptions = hasPipe || hasTransportOption || hasEndpoint || hasToken;
-
-        if (hasDotnetTestTransportOptions && !isDotnetTestCliServer)
+            && DotnetTestCliProtocolName.Equals(serverProtocolArgs[0], StringComparison.OrdinalIgnoreCase)
+            && !commandLineOptions.IsOptionSet(DotNetTestPipeOptionKey))
         {
-            return ValidationResult.InvalidTask(PlatformResources.PlatformCommandLineDotnetTestOptionsRequireServer);
-        }
-
-        if (isDotnetTestCliServer)
-        {
-            // 1. Conflict: a pipe name together with anything WebSocket-shaped (explicit websocket transport, an
-            // endpoint, or a token) - the two transports are mutually exclusive.
-            if (hasPipe && (isWebSocketTransport || hasEndpoint || hasToken))
-            {
-                return ValidationResult.InvalidTask(PlatformResources.PlatformCommandLineDotnetTestTransportConflict);
-            }
-
-            // 2. WebSocket-only options given without selecting the WebSocket transport, and no pipe either: the
-            // more specific and actionable message ("these options require --dotnet-test-transport websocket")
-            // beats the generic "no transport selected" message from step 3 below.
-            if (!hasPipe && !isWebSocketTransport && (hasEndpoint || hasToken))
-            {
-                return ValidationResult.InvalidTask(PlatformResources.PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport);
-            }
-
-            // 3. Nothing selects a transport at all (covers: no options given, or --dotnet-test-transport pipe
-            // given explicitly without the required --dotnet-test-pipe name).
-            if (!hasPipe && !isWebSocketTransport)
-            {
-                return ValidationResult.InvalidTask(
-                    isPipeTransport
-                        ? string.Format(CultureInfo.InvariantCulture, PlatformResources.PlatformCommandLineDotnetTestCliRequiresPipe, DotnetTestCliProtocolName, DotNetTestPipeOptionKey)
-                        : PlatformResources.PlatformCommandLineDotnetTestCliRequiresTransport);
-            }
-
-            // 4. WebSocket transport selected (or implied) but incomplete.
-            if (isWebSocketTransport && (!hasEndpoint || !hasToken))
-            {
-                return ValidationResult.InvalidTask(PlatformResources.PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken);
-            }
-
-            // Reject impossible transport/runtime combinations as early as possible (before we ever try to
-            // construct a NamedPipeClient, which would throw PlatformNotSupportedException deep inside the
-            // connection bootstrap). System.IO.Pipes is not available on either single-threaded wasm runtime.
-            if (hasPipe && OperatingSystem.IsBrowser())
-            {
-                return ValidationResult.InvalidTask(PlatformResources.PlatformCommandLinePipeTransportNotSupportedOnBrowser);
-            }
-
-            if (hasPipe && OperatingSystem.IsWasi())
-            {
-                return ValidationResult.InvalidTask(PlatformResources.PlatformCommandLinePipeTransportNotSupportedOnWasi);
-            }
-
-            // The WebSocket transport is implemented for browser-wasm (via JS interop) and for regular
-            // (non-wasm) runtimes (via System.Net.WebSockets.ClientWebSocket). wasi-wasm has neither a
-            // ClientWebSocket implementation nor an established JS-interop equivalent in this repo, so it is
-            // not yet supported by any transport; fail fast with an actionable message instead of silently
-            // falling back to console mode.
-            if (isWebSocketTransport && OperatingSystem.IsWasi())
-            {
-                return ValidationResult.InvalidTask(PlatformResources.PlatformCommandLineWebSocketTransportNotSupportedOnWasi);
-            }
+            return ValidationResult.InvalidTask(string.Format(CultureInfo.InvariantCulture, PlatformResources.PlatformCommandLineDotnetTestCliRequiresPipe, DotnetTestCliProtocolName, DotNetTestPipeOptionKey));
         }
 
         if (commandLineOptions.IsOptionSet(DiagnosticFileLoggerSynchronousWriteOptionKey))
diff --git a/src/Platform/Microsoft.Testing.Platform/IPC/NamedPipeConnectionBase.cs b/src/Platform/Microsoft.Testing.Platform/IPC/NamedPipeConnectionBase.cs
index 4f0b255e0f..2f91407151 100644
--- a/src/Platform/Microsoft.Testing.Platform/IPC/NamedPipeConnectionBase.cs
+++ b/src/Platform/Microsoft.Testing.Platform/IPC/NamedPipeConnectionBase.cs
@@ -14,11 +14,9 @@
 
 namespace Microsoft.Testing.Platform.IPC;
 
-// Duplex-stream framing/transport shared by NamedPipeServer, NamedPipeClient, and DotnetTestWebSocketClient. This is
-// deliberately NOT part of the source-shared serializer registry (NamedPipeBase): the transport differs per repo
-// (e.g. dotnet/sdk inlines its own read/write loop), so only the registry + serializers are shared. This type stays
-// local to Microsoft.Testing.Platform. It operates on any duplex Stream (PipeStream, a WebSocket-backed Stream, ...);
-// the only pipe-specific behavior (WaitForPipeDrain) is isolated behind an `is PipeStream` check.
+// Named-pipe framing/transport shared by NamedPipeServer and NamedPipeClient. This is deliberately NOT part of the
+// source-shared serializer registry (NamedPipeBase): the transport differs per repo (e.g. dotnet/sdk inlines its own
+// read/write loop), so only the registry + serializers are shared. This type stays local to Microsoft.Testing.Platform.
 [Embedded]
 [SuppressMessage("Design", "CA1001:Types that own disposable fields should be disposable", Justification = "Disposal is delegated to subclasses via DisposeBuffers().")]
 internal abstract class NamedPipeConnectionBase : NamedPipeBase
@@ -30,15 +28,12 @@ internal abstract class NamedPipeConnectionBase : NamedPipeBase
     /// <summary>
     /// Serializes <paramref name="message"/> using <paramref name="serializer"/>, frames it with a
     /// 4-byte size header and 4-byte serializer-ID prefix, writes the frame to <paramref name="stream"/>,
-    /// flushes, and (on Windows, when <paramref name="stream"/> is a named pipe) waits for the pipe to drain.
+    /// flushes, and (on Windows) waits for the pipe to drain.
     /// </summary>
-    /// <remarks>
-    /// This method is transport-neutral: <paramref name="stream"/> may be a <see cref="PipeStream"/> (the
-    /// named-pipe transport) or any other duplex <see cref="Stream"/> (e.g. a WebSocket-backed duplex stream).
-    /// The only pipe-specific behavior - <see cref="PipeStream.WaitForPipeDrain"/> - is isolated behind an
-    /// <c>is PipeStream</c> check so it only ever runs for the named-pipe transport.
-    /// </remarks>
-    protected async Task WriteMessageAsync(Stream stream, INamedPipeSerializer serializer, object message, CancellationToken cancellationToken)
+#if !MTP_MSBUILD_TASKS
+    [UnsupportedOSPlatform("browser")]
+#endif
+    protected async Task WriteMessageAsync(PipeStream stream, INamedPipeSerializer serializer, object message, CancellationToken cancellationToken)
     {
         // Serialize the message body
         _serializationBuffer.Position = 0;
@@ -108,9 +103,9 @@ protected async Task WriteMessageAsync(Stream stream, INamedPipeSerializer seria
             await stream.WriteAsync(_messageBuffer.GetBuffer(), 0, (int)_messageBuffer.Position, cancellationToken).ConfigureAwait(false);
 #endif
             await stream.FlushAsync(cancellationToken).ConfigureAwait(false);
-            if (stream is PipeStream pipeStream && RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
-                pipeStream.WaitForPipeDrain();
+                stream.WaitForPipeDrain();
             }
         }
         finally
@@ -124,10 +119,10 @@ protected async Task WriteMessageAsync(Stream stream, INamedPipeSerializer seria
     /// Reads one complete framed message from <paramref name="stream"/>, deserializes it, and returns
     /// the result.  Returns <see langword="null"/> when the stream reaches EOF (peer disconnected).
     /// </summary>
-    /// <remarks>
-    /// Transport-neutral: see the remarks on <see cref="WriteMessageAsync"/>.
-    /// </remarks>
-    protected async Task<object?> ReadNextMessageAsync(Stream stream, CancellationToken cancellationToken)
+#if !MTP_MSBUILD_TASKS
+    [UnsupportedOSPlatform("browser")]
+#endif
+    protected async Task<object?> ReadNextMessageAsync(PipeStream stream, CancellationToken cancellationToken)
     {
         _messageBuffer.SetLength(0);
 
diff --git a/src/Platform/Microsoft.Testing.Platform/InternalAPI/InternalAPI.Unshipped.txt b/src/Platform/Microsoft.Testing.Platform/InternalAPI/InternalAPI.Unshipped.txt
index de470a8bb3..2cee85ffaa 100644
--- a/src/Platform/Microsoft.Testing.Platform/InternalAPI/InternalAPI.Unshipped.txt
+++ b/src/Platform/Microsoft.Testing.Platform/InternalAPI/InternalAPI.Unshipped.txt
@@ -240,50 +240,3 @@ Microsoft.Testing.Platform.OutputDevice.Terminal.TerminalTestReporter.TerminalTe
 Microsoft.Testing.Platform.OutputDevice.Terminal.TestProgressStateAwareTerminal.TestProgressStateAwareTerminal(Microsoft.Testing.Platform.OutputDevice.Terminal.ITerminal! terminal, System.Func<bool?>! showProgress, Microsoft.Testing.Platform.OutputDevice.Terminal.IProgressRenderer! renderer, Microsoft.Testing.Platform.Logging.ILogger! logger) -> void
 Microsoft.Testing.Platform.ServerMode.ServerModeManager.MessageHandlerFactory.MessageHandlerFactory(string! host, int port, Microsoft.Testing.Platform.OutputDevice.IOutputDevice! outputDevice, Microsoft.Testing.Platform.Logging.ILogger! logger) -> void
 Microsoft.Testing.Platform.ServerMode.TcpMessageHandler.TcpMessageHandler(System.Net.Sockets.TcpClient! client, System.IO.Stream! clientToServerStream, System.IO.Stream! serverToClientStream, Microsoft.Testing.Platform.ServerMode.IMessageFormatter! formatter, Microsoft.Testing.Platform.Logging.ILogger! logger) -> void
-const Microsoft.Testing.Platform.CommandLine.PlatformCommandLineProvider.DotNetTestTransportOptionKey = "dotnet-test-transport" -> string!
-const Microsoft.Testing.Platform.CommandLine.PlatformCommandLineProvider.DotNetTestTransportPipeArgument = "pipe" -> string!
-const Microsoft.Testing.Platform.CommandLine.PlatformCommandLineProvider.DotNetTestTransportWebSocketArgument = "websocket" -> string!
-const Microsoft.Testing.Platform.CommandLine.PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey = "dotnet-test-websocket-endpoint" -> string!
-const Microsoft.Testing.Platform.CommandLine.PlatformCommandLineProvider.DotNetTestWebSocketTokenOptionKey = "dotnet-test-websocket-token" -> string!
-const Microsoft.Testing.Platform.IPC.HandshakeMessagePropertyNames.Transport = 16 -> byte
-const Microsoft.Testing.Platform.IPC.HandshakeMessageTransportNames.NamedPipe = "NamedPipe" -> string!
-const Microsoft.Testing.Platform.IPC.HandshakeMessageTransportNames.WebSocket = "WebSocket" -> string!
-const Microsoft.Testing.Platform.IPC.ProtocolConstants.SupportedVersions = "1.0.0;1.1.0;1.2.0;1.3.0;1.4.0;1.5.0" -> string!
-Microsoft.Testing.Platform.DotnetTestTransportKind
-Microsoft.Testing.Platform.DotnetTestTransportKind.NamedPipe = 0 -> Microsoft.Testing.Platform.DotnetTestTransportKind
-Microsoft.Testing.Platform.DotnetTestTransportKind.WebSocket = 1 -> Microsoft.Testing.Platform.DotnetTestTransportKind
-Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream
-Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.ClientWebSocketDuplexStream(System.Net.WebSockets.WebSocket! webSocket) -> void
-Microsoft.Testing.Platform.IPC.DotnetTestWebSocketClient
-Microsoft.Testing.Platform.IPC.DotnetTestWebSocketClient.ConnectAsync(System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-Microsoft.Testing.Platform.IPC.DotnetTestWebSocketClient.Dispose() -> void
-Microsoft.Testing.Platform.IPC.DotnetTestWebSocketClient.DotnetTestWebSocketClient(System.Uri! endpoint, string! authToken, Microsoft.Testing.Platform.Helpers.IEnvironment! environment, bool exitProcessOnConnectionLoss) -> void
-Microsoft.Testing.Platform.IPC.DotnetTestWebSocketClient.DotnetTestWebSocketClient(System.Uri! endpoint, string! authToken, Microsoft.Testing.Platform.Helpers.IEnvironment! environment) -> void
-Microsoft.Testing.Platform.IPC.DotnetTestWebSocketClient.IsConnected.get -> bool
-Microsoft.Testing.Platform.IPC.DotnetTestWebSocketClient.RequestReplyAsync<TRequest, TResponse>(TRequest request, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<TResponse>!
-Microsoft.Testing.Platform.IPC.HandshakeMessageTransportNames
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Stream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Stream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.ReadNextMessageAsync(System.IO.Pipes.PipeStream! stream, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<object?>!
-*REMOVED*Microsoft.Testing.Platform.IPC.NamedPipeConnectionBase.WriteMessageAsync(System.IO.Pipes.PipeStream! stream, Microsoft.Testing.Platform.IPC.INamedPipeSerializer! serializer, object! message, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.CanRead.get -> bool
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.CanSeek.get -> bool
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.CanWrite.get -> bool
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.Flush() -> void
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.FlushAsync(System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.Length.get -> long
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.Position.get -> long
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.Position.set -> void
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.Read(byte[]! buffer, int offset, int count) -> int
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.ReadAsync(byte[]! buffer, int offset, int count, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<int>!
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.Seek(long offset, System.IO.SeekOrigin origin) -> long
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.SetLength(long value) -> void
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.Write(byte[]! buffer, int offset, int count) -> void
-override Microsoft.Testing.Platform.IPC.ClientWebSocketDuplexStream.WriteAsync(byte[]! buffer, int offset, int count, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-static Microsoft.Testing.Platform.DotnetTestHelper.TryGetDotnetTestTransport(this Microsoft.Testing.Platform.CommandLine.CommandLineHandler! commandLineHandler, out Microsoft.Testing.Platform.DotnetTestTransportKind transport) -> bool
-static Microsoft.Testing.Platform.IPC.DotnetTestWebSocketClient.BuildAuthenticatedUri(System.Uri! endpoint, string! token) -> System.Uri!
-Microsoft.Testing.Platform.CommandLine.CommandLineArgumentsRedactor
-static Microsoft.Testing.Platform.CommandLine.CommandLineArgumentsRedactor.Redact(string![]! args) -> string!
-static Microsoft.Testing.Platform.CommandLine.CommandLineArgumentsRedactor.RedactError(string! error, System.Collections.Generic.IReadOnlyList<string!>! args) -> string!
-[TPEXP]Microsoft.Testing.Platform.CommandLine.CommandLineParseResult.RedactError(string! error) -> string!
-[TPEXP]Microsoft.Testing.Platform.CommandLine.CommandLineParseResult.CommandLineParseResult(string? toolName, System.Collections.Generic.IReadOnlyList<Microsoft.Testing.Platform.CommandLine.CommandLineParseOption!>! options, System.Collections.Generic.IReadOnlyList<string!>! errors, System.Collections.Generic.IReadOnlyList<string!>! arguments, System.Collections.Generic.IReadOnlyList<string!>! expandedArguments) -> void
diff --git a/src/Platform/Microsoft.Testing.Platform/InternalAPI/net/InternalAPI.Unshipped.txt b/src/Platform/Microsoft.Testing.Platform/InternalAPI/net/InternalAPI.Unshipped.txt
index eaec3119dc..ef0dac082d 100644
--- a/src/Platform/Microsoft.Testing.Platform/InternalAPI/net/InternalAPI.Unshipped.txt
+++ b/src/Platform/Microsoft.Testing.Platform/InternalAPI/net/InternalAPI.Unshipped.txt
@@ -3,22 +3,6 @@ static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.ReadFields(Syst
 static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.TryReadExecutionScopedField(System.IO.Stream! stream, ushort fieldId, int fieldSize, ref string? executionId, ref string? instanceId) -> bool
 static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.WriteExecutionScopedHeader(System.IO.Stream! stream, string? executionId, string? instanceId, ushort payloadFieldCount) -> void
 static Microsoft.Testing.Platform.IPC.Serializers.BaseSerializer.WriteListPayload<T>(System.IO.Stream! stream, ushort fieldId, T[]? list, System.Action<System.IO.Stream!, T>! writeItem) -> void
-Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream
-static Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.ConnectAsync(System.Uri! uri, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream!>!
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.CanRead.get -> bool
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.CanSeek.get -> bool
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.CanWrite.get -> bool
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.Flush() -> void
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.FlushAsync(System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.Length.get -> long
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.Position.get -> long
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.Position.set -> void
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.Read(byte[]! buffer, int offset, int count) -> int
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.ReadAsync(byte[]! buffer, int offset, int count, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<int>!
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.Seek(long offset, System.IO.SeekOrigin origin) -> long
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.SetLength(long value) -> void
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.Write(byte[]! buffer, int offset, int count) -> void
-override Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream.WriteAsync(byte[]! buffer, int offset, int count, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
 Microsoft.Testing.Platform.OutputDevice.BrowserOutputDevice.BrowserOutputDevice(Microsoft.Testing.Platform.Helpers.IConsole! console, Microsoft.Testing.Platform.Services.ITestApplicationModuleInfo! testApplicationModuleInfo, Microsoft.Testing.Platform.Helpers.IAsyncMonitor! asyncMonitor, Microsoft.Testing.Platform.Helpers.IRuntimeFeature! runtimeFeature, Microsoft.Testing.Platform.Helpers.IEnvironment! environment, Microsoft.Testing.Platform.Services.IPlatformInformation! platformInformation, Microsoft.Testing.Platform.CommandLine.ICommandLineOptions! commandLineOptions, Microsoft.Testing.Platform.Services.IStopPoliciesService! policiesService) -> void
 override Microsoft.Testing.Platform.OutputDevice.BrowserOutputDevice.DisplayActiveTestProgress.get -> bool
 *REMOVED*Microsoft.Testing.Platform.OutputDevice.BrowserOutputDevice.BrowserOutputDevice(Microsoft.Testing.Platform.Helpers.IConsole! console, Microsoft.Testing.Platform.Services.ITestApplicationModuleInfo! testApplicationModuleInfo, Microsoft.Testing.Platform.Helpers.IAsyncMonitor! asyncMonitor, Microsoft.Testing.Platform.Helpers.IRuntimeFeature! runtimeFeature, Microsoft.Testing.Platform.Helpers.IEnvironment! environment, Microsoft.Testing.Platform.Services.IPlatformInformation! platformInformation, Microsoft.Testing.Platform.Services.IStopPoliciesService! policiesService) -> void
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.cs b/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.cs
index da8c98fbb1..b06cd4e0c0 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.cs
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.cs
@@ -53,28 +53,6 @@ internal static partial class PlatformResources
 
     internal static string @PlatformCommandLineDotnetTestCliRequiresPipe => GetResourceString("PlatformCommandLineDotnetTestCliRequiresPipe");
 
-    internal static string @PlatformCommandLineDotnetTestCliRequiresTransport => GetResourceString("PlatformCommandLineDotnetTestCliRequiresTransport");
-
-    internal static string @PlatformCommandLineDotnetTestOptionsRequireServer => GetResourceString("PlatformCommandLineDotnetTestOptionsRequireServer");
-
-    internal static string @PlatformCommandLineDotnetTestTransportInvalidArgument => GetResourceString("PlatformCommandLineDotnetTestTransportInvalidArgument");
-
-    internal static string @PlatformCommandLineDotnetTestTransportConflict => GetResourceString("PlatformCommandLineDotnetTestTransportConflict");
-
-    internal static string @PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken => GetResourceString("PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken");
-
-    internal static string @PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport => GetResourceString("PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport");
-
-    internal static string @PlatformCommandLineDotnetTestWebSocketEndpointInvalid => GetResourceString("PlatformCommandLineDotnetTestWebSocketEndpointInvalid");
-
-    internal static string @PlatformCommandLineDotnetTestWebSocketTokenEmpty => GetResourceString("PlatformCommandLineDotnetTestWebSocketTokenEmpty");
-
-    internal static string @PlatformCommandLinePipeTransportNotSupportedOnBrowser => GetResourceString("PlatformCommandLinePipeTransportNotSupportedOnBrowser");
-
-    internal static string @PlatformCommandLinePipeTransportNotSupportedOnWasi => GetResourceString("PlatformCommandLinePipeTransportNotSupportedOnWasi");
-
-    internal static string @PlatformCommandLineWebSocketTransportNotSupportedOnWasi => GetResourceString("PlatformCommandLineWebSocketTransportNotSupportedOnWasi");
-
     internal static string @PlatformCommandLineExitOnProcessExitSingleArgument => GetResourceString("PlatformCommandLineExitOnProcessExitSingleArgument");
 
     internal static string @PlatformCommandLineDiagnosticOptionIsMissing => GetResourceString("PlatformCommandLineDiagnosticOptionIsMissing");
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.resx b/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.resx
index 1cd1f6e8be..e89aed2514 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.resx
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.resx
@@ -597,14 +597,6 @@ The default is TestResults in the directory that contains the test application.<
     <value>'--server {0}' requires '--{1}' to be specified.</value>
     <comment>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</comment>
   </data>
-  <data name="PlatformCommandLineDotnetTestCliRequiresTransport" xml:space="preserve">
-    <value>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</value>
-    <comment>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</comment>
-  </data>
-  <data name="PlatformCommandLineDotnetTestOptionsRequireServer" xml:space="preserve">
-    <value>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</value>
-    <comment>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</comment>
-  </data>
   <data name="PlatformCommandLineSkipBuildersNumberCheckOptionDescription" xml:space="preserve">
     <value>For testing purposes</value>
   </data>
@@ -615,54 +607,6 @@ The default is TestResults in the directory that contains the test application.<
     <value>dotnet test pipe.</value>
     <comment>{Locked="dotnet test"}</comment>
   </data>
-  <data name="PlatformCommandLineDotnetTestTransportOptionDescription" xml:space="preserve">
-    <value>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</value>
-    <comment>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</comment>
-  </data>
-  <data name="PlatformCommandLineDotnetTestTransportInvalidArgument" xml:space="preserve">
-    <value>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</value>
-    <comment>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</comment>
-  </data>
-  <data name="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription" xml:space="preserve">
-    <value>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</value>
-    <comment>{Locked="--dotnet-test-transport websocket"}</comment>
-  </data>
-  <data name="PlatformCommandLineDotnetTestWebSocketEndpointInvalid" xml:space="preserve">
-    <value>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</value>
-    <comment>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</comment>
-  </data>
-  <data name="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription" xml:space="preserve">
-    <value>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</value>
-    <comment>{Locked="--dotnet-test-transport websocket"}</comment>
-  </data>
-  <data name="PlatformCommandLineDotnetTestWebSocketTokenEmpty" xml:space="preserve">
-    <value>'--dotnet-test-websocket-token' requires a non-empty value.</value>
-    <comment>{Locked="--dotnet-test-websocket-token"}</comment>
-  </data>
-  <data name="PlatformCommandLineDotnetTestTransportConflict" xml:space="preserve">
-    <value>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</value>
-    <comment>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</comment>
-  </data>
-  <data name="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken" xml:space="preserve">
-    <value>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</value>
-    <comment>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</comment>
-  </data>
-  <data name="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport" xml:space="preserve">
-    <value>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</value>
-    <comment>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</comment>
-  </data>
-  <data name="PlatformCommandLinePipeTransportNotSupportedOnBrowser" xml:space="preserve">
-    <value>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</value>
-    <comment>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</comment>
-  </data>
-  <data name="PlatformCommandLinePipeTransportNotSupportedOnWasi" xml:space="preserve">
-    <value>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</value>
-    <comment>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</comment>
-  </data>
-  <data name="PlatformCommandLineWebSocketTransportNotSupportedOnWasi" xml:space="preserve">
-    <value>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</value>
-    <comment>{Locked="--server dotnettestcli"}</comment>
-  </data>
   <data name="TreeNodeFilterDescription" xml:space="preserve">
     <value>Use a tree filter to filter down the tests to execute</value>
   </data>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.cs.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.cs.xlf
index dab0e1fe53..bd7bba562c 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.cs.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.cs.xlf
@@ -621,66 +621,11 @@ Volitelně přijímá hodnotu „text“ (výchozí výstup čitelný pro člov
         <target state="translated">Parametr „--server {0}“ vyžaduje zadání hodnoty „--{1}“.</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">dotnet test kanál.</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Volitelně přijímá hodnotu „text“ (výchozí výstup čitelný pro člov
         <target state="translated">Nezobrazovat úvodní banner, zprávu o autorských právech ani banner telemetrie</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">Zadejte port serveru.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Takes one argument as a time value with an explicit unit suffix. Accepted suffixes are 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)', and 'd'/'day(s)', e.g. '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">Neplatná hodnota {0} pro parametr --zero-tests-policy. Platné hodnoty jsou {1}.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.de.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.de.xlf
index 45f0888bb0..617918e2f8 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.de.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.de.xlf
@@ -621,66 +621,11 @@ Akzeptiert optional „text“ (die standardmäsige lesbare Ausgabe) oder „jso
         <target state="translated">„--server {0}' reqiueres'--{1}“ muss angegeben werden.</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">dotnet test pipe.</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Akzeptiert optional „text“ (die standardmäsige lesbare Ausgabe) oder „jso
         <target state="translated">Zeigen Sie das Startbanner, die Copyrightmeldung oder das Telemetriebanner nicht an.</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">Geben Sie den Port des Servers an.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Verwendet ein Argument als Zeitwert mit einem expliziten Einheitensuffix. Akzeptierte Suffixe sind 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)', and 'd'/'day(s)', z. B. '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">Ungültiger Wert „{0}“ für „--zero-tests-policy“. Gültige Werte sind „{1}“.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.es.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.es.xlf
index ec61bf0f87..e0960d9b39 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.es.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.es.xlf
@@ -621,66 +621,11 @@ Opcionalmente, acepta "text" (la salida legible por el usuario predeterminada) o
         <target state="translated">La opción "--server {0}" requiere que se especifique "--{1}".</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">canalización de dotnet test</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Opcionalmente, acepta "text" (la salida legible por el usuario predeterminada) o
         <target state="translated">No muestre el banner de inicio, el mensaje de copyright o el banner de telemetría.</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">Especifique el puerto del servidor.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Takes one argument as a time value with an explicit unit suffix. Accepted suffixes are 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)', and 'd'/'day(s)', e.g. '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">Valor no válido "{0}" para "--zero-tests-policy". Los valores válidos son {1}.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.fr.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.fr.xlf
index 713322ca03..13f2c0a0c7 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.fr.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.fr.xlf
@@ -621,66 +621,11 @@ Accepte éventuellement « text » (sortie lisible par l’humain par défaut)
         <target state="translated">« --server {0} » nécessite la spécification de « --{1} ».</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">canal de dotnet test.</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Accepte éventuellement « text » (sortie lisible par l’humain par défaut)
         <target state="translated">Ne pas afficher la bannière de démarrage, le message de copyright ou la bannière de télémétrie.</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">Spécifier le port du serveur.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Prend un argument correspondant à une valeur de temps avec un suffixe d’unité explicite. Les suffixes acceptés sont 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)' et 'd'/'day(s)', par exemple '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">Valeur non valide « {0} » pour « --zero-tests-policy ». Les valeurs valides sont {1}.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.it.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.it.xlf
index f8e662ed12..d1d0ac4313 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.it.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.it.xlf
@@ -621,66 +621,11 @@ Facoltativamente accetta ''text'' (output leggibile predefinito) o ''json'' per
         <target state="translated">'--server {0}' richiede che sia specificato '--{1}'.</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">pipe di dotnet test.</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Facoltativamente accetta ''text'' (output leggibile predefinito) o ''json'' per
         <target state="translated">Non visualizzare il banner di avvio, il messaggio di copyright o il banner di telemetria.</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">Specifica la porta del server.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Accetta un argomento come valore di ora con un suffisso di unità esplicito. I suffissi accettati sono 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)' e 'd'/'day(s)', ad esempio '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">Valore ''{0}'' non valido per ''--zero-tests-policy''. I valori validi sono {1}.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ja.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ja.xlf
index c3ec09d40f..04980f3e0f 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ja.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ja.xlf
@@ -621,66 +621,11 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">'--server {0}' には '--{1}' を指定する必要があります。</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">dotnet test パイプ。</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -753,16 +698,6 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">スタートアップ バナー、著作権メッセージ、テレメトリ バナーは表示しないでください。</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">サーバーのポートを指定します。</target>
@@ -824,11 +759,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 明示的な単位サフィックスを持つ時間値を 1 つ、引数として指定します。使用可能なサフィックスは、'ms'/'mil(s)'/'millisecond(s)'、's'/'sec(s)'/'second(s)'、'm'/'min(s)'/'minute(s)'、'h'/'hour(s)'、'd'/'day(s)' です (例: '500ms'、'5400s'、'90m'、'1.5h'、'1d')。</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">'--zero-tests-policy' の値 '{0}' は無効です。有効な値は {1} です。</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ko.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ko.xlf
index e2b7bb7c45..b569dd3ac1 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ko.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ko.xlf
@@ -621,66 +621,11 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">'--server {0}'를 사용하려면 '--{1}'를 지정해야 합니다.</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">dotnet test 파이프.</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">시작 배너, 저작권 메시지 또는 원격 분석 배너를 표시하지 마세요.</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">서버의 포트를 지정합니다.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 명시적 단위 접미사가 포함된 시간 값을 하나의 인수로 입력해야 합니다. 허용되는 접미사는 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)', 'd'/'day(s)'입니다. (예: '500ms', '5400s', '90m', '1.5h', '1d')</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">'--zero-tests-policy'에 잘못된 값 '{0}'이(가) 지정되었습니다. 유효한 값은 {1}입니다.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pl.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pl.xlf
index 6ec32db6aa..6c871df623 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pl.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pl.xlf
@@ -621,66 +621,11 @@ Opcjonalnie akceptuje „text” (domyślne dane wyjściowe czytelne dla człowi
         <target state="translated">Element „--server {0}„ wymaga określenia elementu „--{1}”.</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">potok dotnet test.</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Opcjonalnie akceptuje „text” (domyślne dane wyjściowe czytelne dla człowi
         <target state="translated">Nie wyświetlaj baneru startowego, komunikatu o prawach autorskich ani transparentu telemetrii.</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">Określ port serwera.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Takes one argument as a time value with an explicit unit suffix. Accepted suffixes are 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)', and 'd'/'day(s)', e.g. '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">Nieprawidłowa wartość „{0}” d; „--zero-tests-policy”. Prawidłowe wartości to {1}.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pt-BR.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pt-BR.xlf
index d9e153e642..d0c2bde469 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pt-BR.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pt-BR.xlf
@@ -621,66 +621,11 @@ Opcionalmente, aceita 'text' (a saída legível por humanos padrão) ou 'json' p
         <target state="translated">''--server {0}'' requer que ''--{1}'' seja especificado.</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">pipe de dotnet test.</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Opcionalmente, aceita 'text' (a saída legível por humanos padrão) ou 'json' p
         <target state="translated">Não exiba a faixa de inicialização, a mensagem de direitos autorais ou a faixa de telemetria.</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">Especifique a porta do servidor.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Recebe um argumento como valor temporal, com um sufixo de unidade explícito. Os sufixos aceitos são 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)' e 'd'/'day(s)'. Por exemplo: '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">Valor inválido "{0}" para "--zero-tests-policy". Os valores válidos são {1}.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ru.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ru.xlf
index 62aa8b25fd..076346dd4a 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ru.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ru.xlf
@@ -621,66 +621,11 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">Для --server {0} требуется указать --{1}.</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">dotnet test канал.</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">Не отображать баннер запуска, сообщение об авторских правах и баннер телеметрии.</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">Укажите порт сервера.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Takes one argument as a time value with an explicit unit suffix. Accepted suffixes are 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)', and 'd'/'day(s)', e.g. '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">Недопустимое значение "{0}" для "--zero-tests-policy". Допустимые значения: {1}.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.tr.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.tr.xlf
index 692fe301cd..fcad947c96 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.tr.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.tr.xlf
@@ -621,66 +621,11 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">'--server {0}' için '--{1}' belirtilmelidir.</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">dotnet test kanalı.</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">Başlangıç başlığını, telif hakkı iletisini veya telemetri başlığını görüntülemez.</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">Sunucunun bağlantı noktasını belirtir.</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Açık bir birim soneki bulunan bir zaman değeri olarak bir bağımsız değişken alır. Kabul edilen sonekler: 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)', and 'd'/'day(s)', ör. '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">'--zero-tests-policy' için geçersiz değer '{0}'. Geçerli değerler {1}.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hans.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hans.xlf
index 9ad55f993e..4b00eca074 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hans.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hans.xlf
@@ -621,66 +621,11 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">“--server {0}”需要指定“--{1}”。</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">dotnet test 管道。</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">请勿显示启动横幅、版权信息或遥测横幅。</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">指定服务器的端口。</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 Takes one argument as a time value with an explicit unit suffix. Accepted suffixes are 'ms'/'mil(s)'/'millisecond(s)', 's'/'sec(s)'/'second(s)', 'm'/'min(s)'/'minute(s)', 'h'/'hour(s)', and 'd'/'day(s)', e.g. '500ms', '5400s', '90m', '1.5h', '1d'.</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">"--zero-tests-policy" 的值“{0}”无效。有效值为 {1}。</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hant.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hant.xlf
index 1131eebdd2..0e94b44533 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hant.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hant.xlf
@@ -621,66 +621,11 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">'--server {0}' 要求指定 '--{1}'。</target>
         <note>{0} is the server protocol value. {1} is the required option name without the leading dashes. {Locked="--server"}{Locked="dotnettestcli"}{Locked="dotnet-test-pipe"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestCliRequiresTransport">
-        <source>'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</source>
-        <target state="new">'--server dotnettestcli' requires either '--dotnet-test-pipe' or '--dotnet-test-transport websocket' with both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token'.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestOptionsRequireServer">
-        <source>'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</source>
-        <target state="new">'--dotnet-test-pipe', '--dotnet-test-transport', '--dotnet-test-websocket-endpoint', and '--dotnet-test-websocket-token' require '--server dotnettestcli'.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineDotnetTestPipe">
         <source>dotnet test pipe.</source>
         <target state="translated">dotnet test 管道。</target>
         <note>{Locked="dotnet test"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportConflict">
-        <source>'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</source>
-        <target state="new">'--dotnet-test-pipe' cannot be combined with '--dotnet-test-transport websocket', '--dotnet-test-websocket-endpoint', or '--dotnet-test-websocket-token'. Choose a single transport.</target>
-        <note>{Locked="--dotnet-test-pipe"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportInvalidArgument">
-        <source>'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</source>
-        <target state="new">'--dotnet-test-transport' received unexpected value '{0}'. Supported values are: {1}.</target>
-        <note>{0} is the unexpected transport value. {1} is the comma-separated list of supported transport values. {Locked="--dotnet-test-transport"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestTransportOptionDescription">
-        <source>Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</source>
-        <target state="new">Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).</target>
-        <note>{Locked="dotnet test"}{Locked="pipe"}{Locked="websocket"}{Locked="--dotnet-test-pipe"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointInvalid">
-        <source>'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' requires an absolute 'ws' or 'wss' URI with a host and without user information or a fragment.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="ws"}{Locked="wss"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketEndpointOptionDescription">
-        <source>The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</source>
-        <target state="new">The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport">
-        <source>'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</source>
-        <target state="new">'--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' require '--dotnet-test-transport websocket' to be specified.</target>
-        <note>{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken">
-        <source>'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</source>
-        <target state="new">'--dotnet-test-transport websocket' requires both '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' to be specified.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenEmpty">
-        <source>'--dotnet-test-websocket-token' requires a non-empty value.</source>
-        <target state="new">'--dotnet-test-websocket-token' requires a non-empty value.</target>
-        <note>{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLineDotnetTestWebSocketTokenOptionDescription">
-        <source>The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</source>
-        <target state="new">The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.</target>
-        <note>{Locked="--dotnet-test-transport websocket"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineExitOnProcessExitInvalidDependentProcess">
         <source>Invalid PID '{0}'
 {1}</source>
@@ -752,16 +697,6 @@ Optionally accepts 'text' (the default human-readable output) or 'json' to print
         <target state="translated">不要顯示啟動橫幅、著作權訊息或遙測橫幅。</target>
         <note />
       </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnBrowser">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on browser-wasm (System.IO.Pipes is unavailable). Use '--dotnet-test-transport websocket' with '--dotnet-test-websocket-endpoint' and '--dotnet-test-websocket-token' instead.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}{Locked="--dotnet-test-transport websocket"}{Locked="--dotnet-test-websocket-endpoint"}{Locked="--dotnet-test-websocket-token"}</note>
-      </trans-unit>
-      <trans-unit id="PlatformCommandLinePipeTransportNotSupportedOnWasi">
-        <source>The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The named-pipe transport for '--server dotnettestcli' is not supported when running on wasi-wasm (System.IO.Pipes is unavailable). No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}{Locked="System.IO.Pipes"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLinePortOptionDescription">
         <source>Specify the port of the server.</source>
         <target state="translated">指定伺服器的連接埠。</target>
@@ -823,11 +758,6 @@ Takes one argument as a time value with an explicit unit suffix. Accepted suffix
 採用一個引數做為具有明確單位後置詞的時間值。接受的後置詞為 'ms'/'mil(s)'/'millisecond(s)'、's'/'sec(s)'/'second(s)'、'm'/'min(s)'/'minute(s)'、'h'/'hour(s)' 和 'd'/'day(s)'，例如 '500ms'、'5400s'、'90m'、'1.5h'、'1d'。</target>
         <note>{Locked="'ms'"}{Locked="'mil(s)'"}{Locked="'millisecond(s)'"}{Locked="'s'"}{Locked="'sec(s)'"}{Locked="'second(s)'"}{Locked="'m'"}{Locked="'min(s)'"}{Locked="'minute(s)'"}{Locked="'h'"}{Locked="'hour(s)'"}{Locked="'d'"}{Locked="'day(s)'"}{Locked="'500ms'"}{Locked="'5400s'"}{Locked="'90m'"}{Locked="'1.5h'"}{Locked="'1d'"}</note>
       </trans-unit>
-      <trans-unit id="PlatformCommandLineWebSocketTransportNotSupportedOnWasi">
-        <source>The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</source>
-        <target state="new">The websocket transport for '--server dotnettestcli' is not supported when running on wasi-wasm. No transport is currently implemented for wasi-wasm.</target>
-        <note>{Locked="--server dotnettestcli"}</note>
-      </trans-unit>
       <trans-unit id="PlatformCommandLineZeroTestsPolicyInvalidArgument">
         <source>Invalid value '{0}' for '--zero-tests-policy'. Valid values are {1}.</source>
         <target state="translated">'--zero-tests-policy' 的無效值 '{0}'。有效的值為 {1}。</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/DotnetTestConnection.cs b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/DotnetTestConnection.cs
index 7fcae950f4..8b67f24b08 100644
--- a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/DotnetTestConnection.cs
+++ b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/DotnetTestConnection.cs
@@ -14,6 +14,7 @@
 
 namespace Microsoft.Testing.Platform;
 
+[UnsupportedOSPlatform("browser")]
 internal sealed class DotnetTestConnection : IPushOnlyProtocol, IDisposable
 {
     private readonly CommandLineHandler _commandLineHandler;
@@ -22,18 +23,9 @@ internal sealed class DotnetTestConnection : IPushOnlyProtocol, IDisposable
     private readonly ITestApplicationCancellationTokenSource _cancellationTokenSource;
     private readonly ILogger _logger;
 
-    // The connected dotnettestcli transport - a NamedPipeClient (the default, System.IO.Pipes-based) or a
-    // DotnetTestWebSocketClient (required on browser-wasm; optional elsewhere). The wire protocol is identical
-    // over either; only the duplex channel underneath differs. See DotnetTestTransportKind.
-    private IClient? _transportClient;
-    private DotnetTestTransportKind? _transportKind;
+    private NamedPipeClient? _dotnetTestPipeClient;
 
-    // The reverse "server control" auxiliary channel is a NamedPipeClient regardless of the primary transport
-    // (see IsCompatibleProtocolAsync); it is only ever populated when IsServerControlChannelSupported is true,
-    // which already excludes browser/wasi.
-#pragma warning disable CA1416
     private NamedPipeClient? _serverControlPipeClient;
-#pragma warning restore CA1416
     private Task? _serverControlListenerTask;
     private CancellationTokenSource? _serverControlListenerCts;
     private string? _serverControlPipeName;
@@ -61,19 +53,17 @@ public DotnetTestConnection(CommandLineHandler commandLineHandler, IEnvironment
         _logger = logger;
     }
 
-    public bool IsServerMode => _transportClient?.IsConnected == true;
+    public bool IsServerMode => _dotnetTestPipeClient?.IsConnected == true;
 
     public Task<IPushOnlyProtocolConsumer> GetDataConsumerAsync()
         => Task.FromResult((IPushOnlyProtocolConsumer)new DotnetTestDataConsumer(this, _environment));
 
     public async Task AfterCommonServiceSetupAsync()
     {
-        // If we are in server mode and a transport was selected, connect using it before anything else can run.
-        // PlatformCommandLineProvider.ValidateCommandLineOptionsAsync has already rejected impossible
-        // combinations (e.g. the named-pipe transport on browser-wasm/wasi-wasm, or conflicting/incomplete
-        // transport options), so by the time we get here exactly one well-formed transport is selected.
+        // If we are in server mode and the pipe name is provided
+        // then, we need to connect to the pipe server.
         if (_commandLineHandler.HasDotnetTestServerOption() &&
-            _commandLineHandler.TryGetDotnetTestTransport(out DotnetTestTransportKind transport))
+            _commandLineHandler.TryGetOptionArgumentList(PlatformCommandLineProvider.DotNetTestPipeOptionKey, out string[]? arguments))
         {
             // The execution id is used to identify the test execution
             // We are storing it as an env var so that it can be read by the test host, test host controller and the test host orchestrator
@@ -83,45 +73,16 @@ public async Task AfterCommonServiceSetupAsync()
                 _environment.SetEnvironmentVariable(EnvironmentVariableConstants.TESTINGPLATFORM_DOTNETTEST_EXECUTIONID, Guid.NewGuid().ToString("N"));
             }
 
-            // CreateNamedPipeClient is never reached on browser/wasi: command-line validation already rejects
-            // the named-pipe transport there (see PlatformCommandLineProvider.ValidateCommandLineOptionsAsync).
-#pragma warning disable CA1416
-            _transportClient = transport == DotnetTestTransportKind.WebSocket
-                ? CreateWebSocketClient()
-                : CreateNamedPipeClient();
-#pragma warning restore CA1416
-            _transportKind = transport;
+            _dotnetTestPipeClient = new(arguments[0], _environment);
+            _dotnetTestPipeClient.RegisterAllSerializers();
 
-            await _transportClient.ConnectAsync(_cancellationTokenSource.CancellationToken).ConfigureAwait(false);
+            await _dotnetTestPipeClient.ConnectAsync(_cancellationTokenSource.CancellationToken).ConfigureAwait(false);
         }
     }
 
-    // Isolated in its own method (rather than inline in AfterCommonServiceSetupAsync) so the
-    // browser/wasi-unsupported annotation is scoped as tightly as possible to just the named-pipe path.
-    [UnsupportedOSPlatform("browser")]
-    [UnsupportedOSPlatform("wasi")]
-    private NamedPipeClient CreateNamedPipeClient()
-    {
-        ApplicationStateGuard.Ensure(_commandLineHandler.TryGetOptionArgumentList(PlatformCommandLineProvider.DotNetTestPipeOptionKey, out string[]? arguments));
-        NamedPipeClient client = new(arguments[0], _environment);
-        client.RegisterAllSerializers();
-        return client;
-    }
-
-    private DotnetTestWebSocketClient CreateWebSocketClient()
-    {
-        ApplicationStateGuard.Ensure(_commandLineHandler.TryGetOptionArgumentList(PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey, out string[]? endpointArguments));
-        ApplicationStateGuard.Ensure(_commandLineHandler.TryGetOptionArgumentList(PlatformCommandLineProvider.DotNetTestWebSocketTokenOptionKey, out string[]? tokenArguments));
-        DotnetTestWebSocketClient client = new(new Uri(endpointArguments[0], UriKind.Absolute), tokenArguments[0], _environment);
-        client.RegisterAllSerializers();
-        return client;
-    }
-
     public async Task HelpInvokedAsync()
     {
-        RoslynDebug.Assert(_transportClient is not null);
-        IClient transportClient = _transportClient
-            ?? throw new InvalidOperationException("The dotnet test transport client is not initialized.");
+        RoslynDebug.Assert(_dotnetTestPipeClient is not null);
 
         List<CommandLineOptionMessage> commandLineHelpOptions = [];
         foreach (ICommandLineOptionsProvider commandLineOptionProvider in _commandLineHandler.CommandLineOptionsProviders)
@@ -141,7 +102,7 @@ public async Task HelpInvokedAsync()
             }
         }
 
-        await transportClient.RequestReplyAsync<CommandLineOptionMessages, VoidResponse>(new CommandLineOptionMessages(_testApplicationModuleInfo.GetCurrentTestApplicationFullPath(), [.. commandLineHelpOptions.OrderBy(option => option.Name)]), _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
+        await _dotnetTestPipeClient.RequestReplyAsync<CommandLineOptionMessages, VoidResponse>(new CommandLineOptionMessages(_testApplicationModuleInfo.GetCurrentTestApplicationFullPath(), [.. commandLineHelpOptions.OrderBy(option => option.Name)]), _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
     }
 
     public bool IsIDE { get; private set; }
@@ -164,9 +125,7 @@ public async Task HelpInvokedAsync()
 
     public async Task<bool> IsCompatibleProtocolAsync(string hostType, IReadOnlyDictionary<byte, string>? additionalHandshakeProperties = null)
     {
-        RoslynDebug.Assert(_transportClient is not null);
-        IClient transportClient = _transportClient
-            ?? throw new InvalidOperationException("The dotnet test transport client is not initialized.");
+        RoslynDebug.Assert(_dotnetTestPipeClient is not null);
 
         string supportedProtocolVersions = ProtocolConstants.SupportedVersions;
         Dictionary<byte, string> properties = new()
@@ -181,7 +140,6 @@ public async Task<bool> IsCompatibleProtocolAsync(string hostType, IReadOnlyDict
             { HandshakeMessagePropertyNames.ExecutionId,  _environment.GetEnvironmentVariable(EnvironmentVariableConstants.TESTINGPLATFORM_DOTNETTEST_EXECUTIONID) ?? string.Empty },
             { HandshakeMessagePropertyNames.InstanceId, InstanceId },
             { HandshakeMessagePropertyNames.ExecutionMode, GetExecutionMode() },
-            { HandshakeMessagePropertyNames.Transport, _transportKind == DotnetTestTransportKind.WebSocket ? HandshakeMessageTransportNames.WebSocket : HandshakeMessageTransportNames.NamedPipe },
         };
 
         if (hostType is HandshakeMessageHostTypes.TestHost or HandshakeMessageHostTypes.ServerTestHost)
@@ -199,7 +157,7 @@ public async Task<bool> IsCompatibleProtocolAsync(string hostType, IReadOnlyDict
 
         HandshakeMessage handshakeMessage = new(properties);
 
-        HandshakeMessage response = await transportClient.RequestReplyAsync<HandshakeMessage, HandshakeMessage>(handshakeMessage, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
+        HandshakeMessage response = await _dotnetTestPipeClient.RequestReplyAsync<HandshakeMessage, HandshakeMessage>(handshakeMessage, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
 
         IsIDE = response.Properties?.TryGetValue(HandshakeMessagePropertyNames.IsIDE, out string? isIDEValue) == true &&
             bool.TryParse(isIDEValue, out bool isIDE) &&
@@ -209,13 +167,7 @@ public async Task<bool> IsCompatibleProtocolAsync(string hostType, IReadOnlyDict
             !RoslynString.IsNullOrEmpty(serverControlPipeName))
         {
             _serverControlPipeName = serverControlPipeName;
-
-            // The reverse "server control" channel is itself a named pipe advertised by the SDK, regardless of
-            // which transport carries the primary data channel. On runtimes without named-pipe support
-            // (browser-wasm, wasi-wasm) we cannot open it, so the feature stays off there - the same
-            // best-effort fallback already used when the SDK simply never advertises the property at all. A
-            // WebSocket-based reverse control channel is a natural follow-up but is out of scope here.
-            IsServerControlChannelSupported = !OperatingSystem.IsBrowser() && !OperatingSystem.IsWasi();
+            IsServerControlChannelSupported = true;
         }
 
         if (response.Properties?.TryGetValue(HandshakeMessagePropertyNames.SupportedProtocolVersions, out string? protocolVersion) is true)
@@ -253,33 +205,33 @@ private string GetAttemptNumber()
 
     public async Task SendMessageAsync(IRequest message)
     {
-        IClient transportClient = _transportClient
-            ?? throw new InvalidOperationException("The dotnet test transport client is not connected.");
+        NamedPipeClient dotnetTestPipeClient = _dotnetTestPipeClient
+            ?? throw new InvalidOperationException("The dotnet test pipe client is not connected.");
 
         switch (message)
         {
             case DiscoveredTestMessages discoveredTestMessages:
-                await transportClient.RequestReplyAsync<DiscoveredTestMessages, VoidResponse>(discoveredTestMessages, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
+                await dotnetTestPipeClient.RequestReplyAsync<DiscoveredTestMessages, VoidResponse>(discoveredTestMessages, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
                 break;
 
             case TestResultMessages testResultMessages:
-                await transportClient.RequestReplyAsync<TestResultMessages, VoidResponse>(testResultMessages, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
+                await dotnetTestPipeClient.RequestReplyAsync<TestResultMessages, VoidResponse>(testResultMessages, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
                 break;
 
             case FileArtifactMessages fileArtifactMessages:
-                await transportClient.RequestReplyAsync<FileArtifactMessages, VoidResponse>(fileArtifactMessages, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
+                await dotnetTestPipeClient.RequestReplyAsync<FileArtifactMessages, VoidResponse>(fileArtifactMessages, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
                 break;
 
             case TestSessionEvent testSessionEvent:
-                await transportClient.RequestReplyAsync<TestSessionEvent, VoidResponse>(testSessionEvent, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
+                await dotnetTestPipeClient.RequestReplyAsync<TestSessionEvent, VoidResponse>(testSessionEvent, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
                 break;
 
             case AzureDevOpsLogMessage azureDevOpsLogMessage:
-                await transportClient.RequestReplyAsync<AzureDevOpsLogMessage, VoidResponse>(azureDevOpsLogMessage, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
+                await dotnetTestPipeClient.RequestReplyAsync<AzureDevOpsLogMessage, VoidResponse>(azureDevOpsLogMessage, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
                 break;
 
             case DisplayMessage displayMessage:
-                await transportClient.RequestReplyAsync<DisplayMessage, VoidResponse>(displayMessage, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
+                await dotnetTestPipeClient.RequestReplyAsync<DisplayMessage, VoidResponse>(displayMessage, _cancellationTokenSource.CancellationToken).ConfigureAwait(false);
                 break;
         }
     }
@@ -315,10 +267,6 @@ public Task StartServerControlChannelAsync(Func<CancellationToken, Task> onCance
 
         // exitProcessOnConnectionLoss: false - a dropped control pipe must not kill the test host; the listener
         // turns it into a cooperative cancel instead.
-        // NamedPipeClient (and ConnectAndListenForServerControlAsync, which takes one) is unsupported on
-        // browser/wasi, but IsServerControlChannelSupported is only ever true when neither is the current
-        // runtime (see IsCompatibleProtocolAsync), so this whole block is unreachable there.
-#pragma warning disable CA1416 // IsServerControlChannelSupported already excludes browser/wasi at the call site.
         var controlClient = new NamedPipeClient(_serverControlPipeName, _environment, exitProcessOnConnectionLoss: false);
         controlClient.RegisterAllSerializers();
         _serverControlPipeClient = controlClient;
@@ -327,12 +275,9 @@ public Task StartServerControlChannelAsync(Func<CancellationToken, Task> onCance
         // slow/absent control server can never delay (or fail) test execution start.
         _serverControlListenerTask = Task.Run(
             () => ConnectAndListenForServerControlAsync(controlClient, onCancelSessionRequestedAsync, _serverControlListenerCts.Token));
-#pragma warning restore CA1416
         return Task.CompletedTask;
     }
 
-    [UnsupportedOSPlatform("browser")]
-    [UnsupportedOSPlatform("wasi")]
     private async Task ConnectAndListenForServerControlAsync(NamedPipeClient controlClient, Func<CancellationToken, Task> onCancelSessionRequestedAsync, CancellationToken cancellationToken)
     {
         try
@@ -356,8 +301,6 @@ private async Task ConnectAndListenForServerControlAsync(NamedPipeClient control
         await ListenForServerControlAsync(controlClient, onCancelSessionRequestedAsync, cancellationToken).ConfigureAwait(false);
     }
 
-    [UnsupportedOSPlatform("browser")]
-    [UnsupportedOSPlatform("wasi")]
     private async Task ListenForServerControlAsync(NamedPipeClient controlClient, Func<CancellationToken, Task> onCancelSessionRequestedAsync, CancellationToken cancellationToken)
     {
         try
@@ -426,9 +369,7 @@ public async Task OnExitAsync()
         // Framework cancellation of an already-parked overlapped read is not reliable - disposing the stream is
         // what forces it to unblock. We cancelled first (above) so the listener treats the resulting failure as
         // shutdown rather than "host gone => cancel".
-#pragma warning disable CA1416 // _serverControlPipeClient is only ever non-null when IsServerControlChannelSupported was true (excludes browser/wasi).
         _serverControlPipeClient?.Dispose();
-#pragma warning restore CA1416
 
         if (_serverControlListenerTask is { } listenerTask)
         {
@@ -446,9 +387,7 @@ public void Dispose()
         _serverControlListenerCts?.Cancel();
 
         // Disposing the pipe client forces a parked read to abort even where token cancellation alone would not.
-#pragma warning disable CA1416 // _serverControlPipeClient is only ever non-null when IsServerControlChannelSupported was true (excludes browser/wasi).
         _serverControlPipeClient?.Dispose();
-#pragma warning restore CA1416
 
         if (_serverControlListenerTask is { } listenerTask)
         {
@@ -465,7 +404,7 @@ public void Dispose()
         }
 
         _serverControlListenerCts?.Dispose();
-        _transportClient?.Dispose();
+        _dotnetTestPipeClient?.Dispose();
     }
 
     private async Task TryLogAsync(LogLevel logLevel, string message)
diff --git a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/DotnetTestHelper.cs b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/DotnetTestHelper.cs
index 6eb667eccd..ad9aeaa230 100644
--- a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/DotnetTestHelper.cs
+++ b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/DotnetTestHelper.cs
@@ -5,57 +5,10 @@
 
 namespace Microsoft.Testing.Platform;
 
-/// <summary>
-/// The pre-launch transport selected for the 'dotnet test' pipe protocol (a.k.a. dotnettestcli). The wire
-/// protocol itself (message/serializer/version contract) is identical regardless of which value is selected -
-/// only the duplex channel that carries it differs. See <c>docs/mstest-runner-protocol/004-protocol-dotnet-test-pipe.md</c>.
-/// </summary>
-internal enum DotnetTestTransportKind
-{
-    /// <summary>
-    /// The original <see cref="System.IO.Pipes"/>-based transport, selected via <c>--dotnet-test-pipe</c>. This
-    /// is the default whenever only that option is present, preserving exact wire and behavioral compatibility.
-    /// Not available on <c>browser-wasm</c> or <c>wasi-wasm</c> (no named-pipe support on either runtime).
-    /// </summary>
-    NamedPipe,
-
-    /// <summary>
-    /// The WebSocket-based transport, selected via <c>--dotnet-test-transport websocket</c> together with
-    /// <c>--dotnet-test-websocket-endpoint</c> and <c>--dotnet-test-websocket-token</c>. Required on
-    /// <c>browser-wasm</c>; optional elsewhere.
-    /// </summary>
-    WebSocket,
-}
-
 internal static class DotnetTestHelper
 {
     public static bool HasDotnetTestServerOption(this CommandLineHandler commandLineHandler) =>
         commandLineHandler.TryGetOptionArgumentList(PlatformCommandLineProvider.ServerOptionKey, out string[]? serverArgs) &&
         serverArgs.Length == 1 &&
         serverArgs[0].Equals(PlatformCommandLineProvider.DotnetTestCliProtocolName, StringComparison.OrdinalIgnoreCase);
-
-    /// <summary>
-    /// Resolves which transport carries the dotnettestcli protocol for this process, mirroring the validation
-    /// already enforced by <see cref="PlatformCommandLineProvider.ValidateCommandLineOptionsAsync"/> (which
-    /// guarantees, by the time this runs, that exactly one of the two option groups below is present).
-    /// </summary>
-    public static bool TryGetDotnetTestTransport(this CommandLineHandler commandLineHandler, out DotnetTestTransportKind transport)
-    {
-        if (commandLineHandler.TryGetOptionArgumentList(PlatformCommandLineProvider.DotNetTestTransportOptionKey, out string[]? transportArgs) &&
-            transportArgs is { Length: 1 } &&
-            PlatformCommandLineProvider.DotNetTestTransportWebSocketArgument.Equals(transportArgs[0], StringComparison.OrdinalIgnoreCase))
-        {
-            transport = DotnetTestTransportKind.WebSocket;
-            return true;
-        }
-
-        if (commandLineHandler.IsOptionSet(PlatformCommandLineProvider.DotNetTestPipeOptionKey))
-        {
-            transport = DotnetTestTransportKind.NamedPipe;
-            return true;
-        }
-
-        transport = default;
-        return false;
-    }
 }
diff --git a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/IPC/Constants.cs b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/IPC/Constants.cs
index b296e102d3..8e11c4ba1b 100644
--- a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/IPC/Constants.cs
+++ b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/IPC/Constants.cs
@@ -95,25 +95,6 @@ internal static class HandshakeMessagePropertyNames
 
     // Semicolon-separated lowercase file extensions used as a compatibility fallback for untagged artifacts.
     internal const byte SupportedPostProcessorExtensionsLegacy = 15;
-
-    // Identifies which pre-launch transport carried this handshake: a value from HandshakeMessageTransportNames
-    // ("NamedPipe" or "WebSocket"). The wire protocol is identical over either transport; this property exists
-    // purely for diagnostics/telemetry and future negotiation (e.g. so the SDK can log or validate which
-    // transport a given connecting process actually used). Always sent by the test host / test host controller
-    // / orchestrator; an older SDK that does not recognize the id simply ignores it, so it is not gated on the
-    // negotiated protocol version, but ProtocolConstants.SupportedVersions was still bumped to 1.5.0 alongside it
-    // so the negotiated-version state advances in lockstep with the other additive capabilities in this file.
-    internal const byte Transport = 16;
-}
-
-[Embedded]
-internal static class HandshakeMessageTransportNames
-{
-    // System.IO.Pipes-based transport (the original, default transport selected via --dotnet-test-pipe).
-    internal const string NamedPipe = "NamedPipe";
-
-    // WebSocket-based transport (selected via --dotnet-test-transport websocket), required on browser-wasm.
-    internal const string WebSocket = "WebSocket";
 }
 
 [Embedded]
@@ -203,12 +184,5 @@ internal static class ProtocolConstants
     // --timeout, ...). The feature is gated on the presence of the handshake property (a capability), not on this
     // version string, so an older SDK that never advertises the pipe leaves the feature disabled. The version is
     // still bumped so the negotiated-version state advances in lockstep.
-    // 1.5.0 adds the Transport handshake property (HandshakeMessagePropertyNames.Transport): the test host now
-    // always reports which pre-launch transport it connected over ("NamedPipe" or "WebSocket" - see
-    // HandshakeMessageTransportNames). This is a capability-style property gated on presence, not on this version
-    // string, so an older SDK that does not look at it is unaffected; the version is bumped only so the
-    // negotiated-version state advances in lockstep with the other additive capabilities in this file. Introduced
-    // alongside the WebSocket transport (docs/mstest-runner-protocol/004-protocol-dotnet-test-pipe.md), which is
-    // required to bootstrap the dotnettestcli protocol on runtimes without System.IO.Pipes support (browser-wasm).
-    internal const string SupportedVersions = "1.0.0;1.1.0;1.2.0;1.3.0;1.4.0;1.5.0";
+    internal const string SupportedVersions = "1.0.0;1.1.0;1.2.0;1.3.0;1.4.0";
 }
diff --git a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/IPC/DotnetTestDataConsumer.cs b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/IPC/DotnetTestDataConsumer.cs
index 09a3b89fc5..a362ed4eda 100644
--- a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/IPC/DotnetTestDataConsumer.cs
+++ b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/IPC/DotnetTestDataConsumer.cs
@@ -10,6 +10,7 @@
 
 namespace Microsoft.Testing.Platform.IPC;
 
+[UnsupportedOSPlatform("browser")]
 internal sealed class DotnetTestDataConsumer : IPushOnlyProtocolConsumer
 {
     private readonly DotnetTestConnection? _dotnetTestConnection;
diff --git a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/Transport/BrowserWebSocketDuplexStream.cs b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/Transport/BrowserWebSocketDuplexStream.cs
deleted file mode 100644
index fcddcbd2e1..0000000000
--- a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/Transport/BrowserWebSocketDuplexStream.cs
+++ /dev/null
@@ -1,442 +0,0 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-#if NET7_0_OR_GREATER
-using System.Runtime.InteropServices.JavaScript;
-
-namespace Microsoft.Testing.Platform.IPC;
-
-/// <summary>
-/// Adapts a browser-native <c>WebSocket</c> object (reached through JS interop, following the same
-/// <c>[JSImport]</c> pattern as <see cref="OutputDevice.BrowserOutputDevice"/>) to a duplex
-/// <see cref="Stream"/>, so the transport-neutral framing in <see cref="NamedPipeConnectionBase"/> can drive it
-/// unchanged - the same way <see cref="ClientWebSocketDuplexStream"/> adapts <see cref="System.Net.WebSockets.ClientWebSocket"/>
-/// on non-browser runtimes. <see cref="System.Net.WebSockets.ClientWebSocket"/> is not implemented on
-/// <c>browser-wasm</c> (it throws <see cref="PlatformNotSupportedException"/>), so this type talks to the
-/// browser's own <c>WebSocket</c> API directly instead.
-/// </summary>
-/// <remarks>
-/// <para>
-/// The companion JS module is embedded as a string constant and imported through a <c>data:</c> URL via
-/// <see cref="JSHost.ImportAsync(string, string, System.Threading.CancellationToken)"/>. This keeps the browser
-/// transport fully self-contained in this file - no changes to the generated wasm bootstrap/entry point or to
-/// the published asset set are required, unlike a conventional <c>.js</c> asset shipped alongside the app.
-/// </para>
-/// <para>
-/// Each connection owns one JS <c>WebSocket</c> object (kept alive on the .NET side as a <see cref="JSObject"/>
-/// proxy). <c>send</c> writes one binary frame per call, mirroring the one-frame-per-<c>WriteAsync</c> contract
-/// the framing layer already relies on for named pipes and the non-browser WebSocket adapter. Frames are
-/// exchanged as base64 strings (see the module source for why) rather than raw bytes. <c>receive</c> returns
-/// the next queued message, or a reserved non-base64 sentinel once the socket has closed - messages arriving
-/// before the .NET side calls <c>receive</c> are buffered in a JS-side queue so no data is lost while a
-/// request/reply round-trip is in flight.
-/// </para>
-/// </remarks>
-[SupportedOSPlatform("browser")]
-internal sealed partial class BrowserWebSocketDuplexStream : Stream
-{
-    private const string ModuleName = "Microsoft.Testing.Platform/DotnetTestWebSocket";
-    private const string ClosedSentinel = "__MTP_WEBSOCKET_CLOSED__";
-
-    // language=javascript
-    private const string ModuleSource = """
-        const pendingOpens = new Map();
-
-        export function open(url, connectionId) {
-            return new Promise((resolve, reject) => {
-                let ws;
-                try {
-                    ws = new WebSocket(url);
-                } catch (e) {
-                    reject(e);
-                    return;
-                }
-
-                ws.binaryType = "arraybuffer";
-                ws._queue = [];
-                ws._waiter = null;
-                ws._closed = false;
-                ws._openRejected = false;
-                pendingOpens.set(connectionId, { ws, reject });
-
-                ws.onopen = () => {
-                    pendingOpens.delete(connectionId);
-                    resolve(ws);
-                };
-                ws.onerror = () => {
-                    if (!ws._openRejected) {
-                        ws._openRejected = true;
-                        pendingOpens.delete(connectionId);
-                        reject(new Error("The WebSocket connection failed or was refused by the peer."));
-                    }
-                };
-                ws.onmessage = (ev) => {
-                    const data = new Uint8Array(ev.data);
-                    if (ws._waiter) {
-                        const waiter = ws._waiter;
-                        ws._waiter = null;
-                        waiter.resolve(toBase64(data));
-                    } else {
-                        ws._queue.push(data);
-                    }
-                };
-                ws.onclose = () => {
-                    ws._closed = true;
-                    if (pendingOpens.delete(connectionId) && !ws._openRejected) {
-                        ws._openRejected = true;
-                        reject(new Error("The WebSocket connection closed before opening."));
-                    }
-                    if (ws._waiter) {
-                        const waiter = ws._waiter;
-                        ws._waiter = null;
-                        waiter.resolve("__MTP_WEBSOCKET_CLOSED__");
-                    }
-                };
-            });
-        }
-
-        export function cancelOpen(connectionId) {
-            const pending = pendingOpens.get(connectionId);
-            if (!pending) {
-                return;
-            }
-
-            pendingOpens.delete(connectionId);
-            pending.ws._openRejected = true;
-            pending.reject(new Error("The WebSocket connection attempt was cancelled."));
-            pending.ws.onopen = () => {
-                try {
-                    pending.ws.close();
-                } catch {
-                    // Best-effort close if the host completes the upgrade after cancellation.
-                }
-            };
-            try {
-                pending.ws.close();
-            } catch {
-                // Best-effort: the host may reject close while the socket is still transitioning.
-            }
-        }
-
-        export function pendingOpenCount() {
-            return pendingOpens.size;
-        }
-
-        // Data is exchanged as base64 strings rather than raw byte arrays: the wasm JS-interop source
-        // generator does not support marshalling byte[]/Uint8Array across an async (Task-returning) boundary,
-        // but string marshalling is always supported. The close sentinel contains characters that are invalid in
-        // base64 so it cannot collide with any legal message, including a zero-length binary message ("").
-        function toBase64(bytes) {
-            // Avoid spreading very large arrays into String.fromCharCode (call-stack argument limits);
-            // build the binary string in bounded chunks instead.
-            let binary = "";
-            const chunkSize = 0x8000;
-            for (let i = 0; i < bytes.length; i += chunkSize) {
-                binary += String.fromCharCode.apply(null, bytes.subarray(i, i + chunkSize));
-            }
-
-            return btoa(binary);
-        }
-
-        function fromBase64(base64) {
-            const binary = atob(base64);
-            const bytes = new Uint8Array(binary.length);
-            for (let i = 0; i < binary.length; i++) {
-                bytes[i] = binary.charCodeAt(i);
-            }
-
-            return bytes;
-        }
-
-        export function send(ws, base64Data) {
-            ws.send(fromBase64(base64Data));
-        }
-
-        export function receive(ws) {
-            if (ws._queue.length > 0) {
-                return Promise.resolve(toBase64(ws._queue.shift()));
-            }
-
-            if (ws._closed) {
-                return Promise.resolve("__MTP_WEBSOCKET_CLOSED__");
-            }
-
-            return new Promise((resolve, reject) => {
-                ws._waiter = { resolve, reject };
-            });
-        }
-
-        // Called when the .NET side cancels a pending receive() (see WaitForReceiveAsync). Clears the waiter so
-        // that a message arriving afterward is queued for the *next* receive() call instead of being handed to
-        // this now-abandoned one and silently lost. Resolving the abandoned promise (rather than leaving it
-        // permanently pending) also lets the JS engine release it instead of holding onto its closure forever.
-        export function cancelReceive(ws) {
-            if (ws._waiter) {
-                const waiter = ws._waiter;
-                ws._waiter = null;
-                waiter.resolve("__MTP_WEBSOCKET_CLOSED__");
-                return true;
-            }
-
-            // Delivery already claimed and cleared the waiter. The .NET side must consume that completed
-            // receive rather than throw cancellation and strand the delivered payload on an abandoned task.
-            return false;
-        }
-
-        export function close(ws) {
-            try {
-                ws.close();
-            } catch {
-                // Best-effort: the socket may already be closed/closing.
-            }
-        }
-        """;
-
-    private static Task? s_moduleReady;
-    private static int s_nextConnectionId;
-
-    private readonly JSObject _socket;
-    private byte[] _pendingRead = [];
-    private int _pendingReadOffset;
-    private bool _disposed;
-
-    private BrowserWebSocketDuplexStream(JSObject socket) => _socket = socket;
-
-    /// <summary>
-    /// Imports the companion JS module (idempotent - safe to call before every connection attempt) and opens a
-    /// new browser WebSocket to <paramref name="uri"/>. The returned stream is only valid once the JS <c>onopen</c>
-    /// event has fired; a connection failure (refused, DNS, TLS, ...) surfaces as an awaited exception here rather
-    /// than being discovered on the first read/write.
-    /// </summary>
-    public static async Task<BrowserWebSocketDuplexStream> ConnectAsync(Uri uri, CancellationToken cancellationToken)
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-
-        s_moduleReady ??= JSHost.ImportAsync(ModuleName, $"data:text/javascript;charset=utf-8;base64,{Convert.ToBase64String(Encoding.UTF8.GetBytes(ModuleSource))}", CancellationToken.None);
-        await s_moduleReady.WaitAsync(cancellationToken).ConfigureAwait(false);
-
-        int connectionId = Interlocked.Increment(ref s_nextConnectionId);
-        Task<JSObject> openTask = OpenAsync(uri.ToString(), connectionId);
-        try
-        {
-            JSObject socket = await openTask.WaitAsync(cancellationToken).ConfigureAwait(false);
-            return new BrowserWebSocketDuplexStream(socket);
-        }
-        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
-        {
-            try
-            {
-                CancelOpen(connectionId);
-            }
-            catch (JSException)
-            {
-                // Best-effort: opening may have completed or failed while cancellation was being observed.
-            }
-
-            _ = CloseSocketWhenOpenedAsync(openTask);
-            throw;
-        }
-    }
-
-    private static async Task CloseSocketWhenOpenedAsync(Task<JSObject> openTask)
-    {
-        try
-        {
-            JSObject socket = await openTask.ConfigureAwait(false);
-            try
-            {
-                Close(socket);
-            }
-            catch (JSException)
-            {
-                // Best-effort close after a cancelled connection attempt.
-            }
-            finally
-            {
-                socket.Dispose();
-            }
-        }
-        catch (JSException)
-        {
-            // Observe a connection failure that completed after the caller was already cancelled.
-        }
-    }
-
-    public override bool CanRead => true;
-
-    public override bool CanWrite => true;
-
-    public override bool CanSeek => false;
-
-    public override long Length => throw new NotSupportedException();
-
-    public override long Position
-    {
-        get => throw new NotSupportedException();
-        set
-        {
-            _ = value;
-            throw new NotSupportedException();
-        }
-    }
-
-    public override void Flush()
-    {
-    }
-
-    public override Task FlushAsync(CancellationToken cancellationToken) => Task.CompletedTask;
-
-    public override long Seek(long offset, SeekOrigin origin) => throw new NotSupportedException();
-
-    public override void SetLength(long value) => throw new NotSupportedException();
-
-    public override int Read(byte[] buffer, int offset, int count)
-        => throw new NotSupportedException($"{nameof(BrowserWebSocketDuplexStream)} only supports asynchronous reads.");
-
-    public override void Write(byte[] buffer, int offset, int count)
-        => throw new NotSupportedException($"{nameof(BrowserWebSocketDuplexStream)} only supports asynchronous writes.");
-
-    public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-    {
-        while (count > 0 && _pendingReadOffset >= _pendingRead.Length)
-        {
-            string next = await WaitForReceiveAsync(cancellationToken).ConfigureAwait(false);
-
-            if (next == ClosedSentinel)
-            {
-                return 0;
-            }
-
-            _pendingRead = Convert.FromBase64String(next);
-            _pendingReadOffset = 0;
-
-            // A zero-length binary WebSocket message is legal and is not EOF. Keep receiving until data or the
-            // distinct close sentinel arrives, matching ClientWebSocketDuplexStream.
-        }
-
-        int toCopy = Math.Min(count, _pendingRead.Length - _pendingReadOffset);
-        Array.Copy(_pendingRead, _pendingReadOffset, buffer, offset, toCopy);
-        _pendingReadOffset += toCopy;
-        return toCopy;
-    }
-
-    /// <summary>
-    /// Awaits the JS-side <c>receive()</c> promise while honoring <paramref name="cancellationToken"/>, even
-    /// though the promise itself has no cancellation hook across the interop boundary.
-    /// </summary>
-    /// <remarks>
-    /// Without this, a caller that cancels a pending read (e.g. <see cref="DotnetTestWebSocketClient.RequestReplyAsync{TRequest, TResponse}"/>
-    /// racing a timeout, or a shutdown path) would hang until the peer either sends more data or closes the
-    /// socket - on <c>browser-wasm</c>, the very runtime this transport exists for, that would be an unrecoverable
-    /// hang. This races the receive against the token and throws <see cref="OperationCanceledException"/> as
-    /// soon as it fires.
-    /// <para>
-    /// On cancellation, <see cref="CancelReceive"/> is called (best-effort) to clear the abandoned JS-side
-    /// waiter. This is not just cleanup: without it, the *next* message the peer sends after the cancellation
-    /// would resolve the stale, unobserved promise instead of being queued - silently losing that message from
-    /// the point of view of whichever call replaces this one. <see cref="CancelReceive"/> ensures a message that
-    /// arrives after cancellation is queued normally instead. Closing the socket itself is deliberately not part
-    /// of this - a cancelled read must not affect the connection's ability to serve a subsequent read.
-    /// </para>
-    /// </remarks>
-    private async Task<string> WaitForReceiveAsync(CancellationToken cancellationToken)
-    {
-        cancellationToken.ThrowIfCancellationRequested();
-        Task<string> receiveTask = ReceiveAsync(_socket);
-        if (!cancellationToken.CanBeCanceled)
-        {
-            return await receiveTask.ConfigureAwait(false);
-        }
-
-        TaskCompletionSource<bool> cancellationTcs = new(TaskCreationOptions.RunContinuationsAsynchronously);
-        using (cancellationToken.Register(static state => ((TaskCompletionSource<bool>)state!).TrySetResult(true), cancellationTcs))
-        {
-            Task completed = await Task.WhenAny(receiveTask, cancellationTcs.Task).ConfigureAwait(false);
-            if (completed == cancellationTcs.Task)
-            {
-                bool cancellationWon;
-                try
-                {
-                    cancellationWon = CancelReceive(_socket);
-                }
-                catch (JSException)
-                {
-                    // Best-effort: the socket may already be gone (closed/disposed racing with this cancellation).
-                    cancellationWon = true;
-                }
-
-                if (cancellationWon)
-                {
-                    cancellationToken.ThrowIfCancellationRequested();
-                }
-            }
-        }
-
-        return await receiveTask.ConfigureAwait(false);
-    }
-
-    public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-    {
-        // Send() is a synchronous JS call (WebSocket.send buffers the frame internally and returns immediately),
-        // so there is no in-flight operation to race against the token the way WaitForReceiveAsync races a
-        // receive; the only meaningful cancellation behavior is rejecting an already-cancelled token before
-        // doing the (synchronous, uncancellable-once-started) work, exactly like other synchronous-under-the-hood
-        // Stream implementations do.
-        cancellationToken.ThrowIfCancellationRequested();
-        try
-        {
-            Send(_socket, Convert.ToBase64String(buffer, offset, count));
-        }
-        catch (JSException ex)
-        {
-            throw new IOException("The WebSocket send failed.", ex);
-        }
-
-        await Task.CompletedTask.ConfigureAwait(false);
-    }
-
-    protected override void Dispose(bool disposing)
-    {
-        if (!_disposed && disposing)
-        {
-            try
-            {
-                Close(_socket);
-            }
-            catch (JSException)
-            {
-                // Best-effort close; the socket may already be gone (peer closed first, page navigating away, ...).
-            }
-            finally
-            {
-                _socket.Dispose();
-                _disposed = true;
-            }
-        }
-
-        base.Dispose(disposing);
-    }
-
-    [JSImport("open", ModuleName)]
-    private static partial Task<JSObject> OpenAsync(string url, int connectionId);
-
-    [JSImport("cancelOpen", ModuleName)]
-    private static partial void CancelOpen(int connectionId);
-
-    [JSImport("pendingOpenCount", ModuleName)]
-    private static partial int GetPendingOpenCount();
-
-    [JSImport("send", ModuleName)]
-    private static partial void Send(JSObject socket, string base64Data);
-
-    [JSImport("receive", ModuleName)]
-    private static partial Task<string> ReceiveAsync(JSObject socket);
-
-    [JSImport("cancelReceive", ModuleName)]
-    private static partial bool CancelReceive(JSObject socket);
-
-    [JSImport("close", ModuleName)]
-    private static partial void Close(JSObject socket);
-}
-
-#endif
diff --git a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/Transport/ClientWebSocketDuplexStream.cs b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/Transport/ClientWebSocketDuplexStream.cs
deleted file mode 100644
index 585fdb2afb..0000000000
--- a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/Transport/ClientWebSocketDuplexStream.cs
+++ /dev/null
@@ -1,118 +0,0 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-using System.Net.WebSockets;
-
-namespace Microsoft.Testing.Platform.IPC;
-
-/// <summary>
-/// Adapts a connected <see cref="System.Net.WebSockets.WebSocket"/> (typically a client-side
-/// <see cref="System.Net.WebSockets.ClientWebSocket"/>, but any concrete <see cref="WebSocket"/> works - e.g. a
-/// server-side socket obtained from an HTTP listener, which is how tests exercise this adapter without a real
-/// peer) to a duplex <see cref="Stream"/> so the transport-neutral framing in <see cref="NamedPipeConnectionBase"/>
-/// (originally written against <see cref="System.IO.Pipes.PipeStream"/>) can drive it unchanged. Each
-/// <c>WriteAsync</c> call from the framing layer writes exactly one already-assembled frame, so it maps 1:1 to
-/// one binary WebSocket message (<c>endOfMessage: true</c>). Reads are treated as a plain byte stream:
-/// consecutive <see cref="WebSocket.ReceiveAsync(ArraySegment{byte}, CancellationToken)"/> chunks are handed back
-/// verbatim (buffering any leftover bytes across calls) without relying on message boundaries, which keeps this
-/// adapter correct regardless of how the peer chooses to fragment its writes.
-/// </summary>
-/// <remarks>
-/// This adapter is for non-browser runtimes only: <see cref="System.Net.WebSockets.ClientWebSocket"/> throws
-/// <see cref="PlatformNotSupportedException"/> on <c>browser-wasm</c>. See <c>BrowserWebSocketDuplexStream</c>
-/// for the browser-specific JS-interop implementation.
-/// </remarks>
-[UnsupportedOSPlatform("browser")]
-internal sealed class ClientWebSocketDuplexStream : Stream
-{
-    private readonly WebSocket _webSocket;
-    private readonly byte[] _receiveBuffer = new byte[8192];
-    private int _receiveOffset;
-    private int _receiveCount;
-    private bool _disposed;
-
-    public ClientWebSocketDuplexStream(WebSocket webSocket) => _webSocket = webSocket;
-
-    public override bool CanRead => true;
-
-    public override bool CanWrite => true;
-
-    public override bool CanSeek => false;
-
-    public override long Length => throw new NotSupportedException();
-
-    public override long Position
-    {
-        get => throw new NotSupportedException();
-        set
-        {
-            _ = value;
-            throw new NotSupportedException();
-        }
-    }
-
-    public override void Flush()
-    {
-        // WebSocket sends are not buffered on our side; nothing to flush.
-    }
-
-    public override Task FlushAsync(CancellationToken cancellationToken) => Task.CompletedTask;
-
-    public override long Seek(long offset, SeekOrigin origin) => throw new NotSupportedException();
-
-    public override void SetLength(long value) => throw new NotSupportedException();
-
-    public override int Read(byte[] buffer, int offset, int count)
-        => throw new NotSupportedException($"{nameof(ClientWebSocketDuplexStream)} only supports asynchronous reads.");
-
-    public override void Write(byte[] buffer, int offset, int count)
-        => throw new NotSupportedException($"{nameof(ClientWebSocketDuplexStream)} only supports asynchronous writes.");
-
-    public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-    {
-        // A loop, not recursion: WebSocket.ReceiveAsync frequently completes synchronously when data is already
-        // buffered (common over loopback), so a recursive retry here would consume a real stack frame per
-        // zero-byte message with no opportunity for the awaited continuation to yield - a peer that sends many
-        // consecutive zero-byte messages (deliberately or due to a bug) could drive that recursion arbitrarily
-        // deep and crash the process with an uncatchable StackOverflowException. A loop has no such bound.
-        while (count > 0 && _receiveCount == 0)
-        {
-            WebSocketReceiveResult result = await _webSocket.ReceiveAsync(new ArraySegment<byte>(_receiveBuffer), cancellationToken).ConfigureAwait(false);
-            if (result.MessageType == WebSocketMessageType.Close)
-            {
-                return 0;
-            }
-
-            _receiveOffset = 0;
-            _receiveCount = result.Count;
-
-            // A binary frame (or an individual fragment of one) can legitimately carry zero bytes (e.g. an
-            // empty keep-alive, or a zero-byte fragment followed by more fragments); loop rather than reporting
-            // a false EOF. Only a Close frame (handled above) means the peer actually disconnected - a
-            // zero-byte non-Close result, whether or not it is the final fragment of its message, must not be
-            // returned as 0 (which Stream.Read/ReadAsync conventionally means EOF). The framing layer above
-            // always reads a bounded number of bytes so this cannot spin indefinitely against a well-behaved
-            // peer.
-        }
-
-        int toCopy = Math.Min(count, _receiveCount);
-        Array.Copy(_receiveBuffer, _receiveOffset, buffer, offset, toCopy);
-        _receiveOffset += toCopy;
-        _receiveCount -= toCopy;
-        return toCopy;
-    }
-
-    public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
-        => await _webSocket.SendAsync(new ArraySegment<byte>(buffer, offset, count), WebSocketMessageType.Binary, endOfMessage: true, cancellationToken).ConfigureAwait(false);
-
-    protected override void Dispose(bool disposing)
-    {
-        if (!_disposed && disposing)
-        {
-            _webSocket.Dispose();
-            _disposed = true;
-        }
-
-        base.Dispose(disposing);
-    }
-}
diff --git a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/Transport/DotnetTestWebSocketClient.cs b/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/Transport/DotnetTestWebSocketClient.cs
deleted file mode 100644
index 735293ff5a..0000000000
--- a/src/Platform/Microsoft.Testing.Platform/ServerMode/DotnetTest/Transport/DotnetTestWebSocketClient.cs
+++ /dev/null
@@ -1,240 +0,0 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-using System.Net.WebSockets;
-
-using Microsoft.Testing.Platform.Helpers;
-
-namespace Microsoft.Testing.Platform.IPC;
-
-/// <summary>
-/// A <see cref="IClient"/> implementation of the 'dotnet test' pipe protocol (a.k.a. dotnettestcli) over a
-/// WebSocket transport instead of a named pipe. This is the transport used on runtimes that cannot open
-/// <see cref="System.IO.Pipes"/> connections - today, <c>browser-wasm</c> (via <c>BrowserWebSocketDuplexStream</c>);
-/// it is also available on every other runtime (via <see cref="ClientWebSocketDuplexStream"/>, wrapping
-/// <see cref="ClientWebSocket"/>) for testing and for scenarios where a loopback WebSocket gateway is preferable
-/// to a named pipe (e.g. crossing a container/sandbox boundary).
-/// </summary>
-/// <remarks>
-/// The wire protocol (message/serializer/version contract, framing) is entirely unchanged from the named-pipe
-/// transport: this class reuses <see cref="NamedPipeConnectionBase.WriteMessageAsync"/> and
-/// <see cref="NamedPipeConnectionBase.ReadNextMessageAsync"/> against whichever duplex <see cref="Stream"/>
-/// <see cref="ConnectAsync"/> produces. Only the connection bootstrap (how the duplex channel is established
-/// and authenticated) differs from <see cref="NamedPipeClient"/>.
-/// </remarks>
-internal sealed class DotnetTestWebSocketClient : NamedPipeConnectionBase, IClient
-{
-    private readonly Uri _endpoint;
-    private readonly string _authToken;
-    private readonly IEnvironment _environment;
-    private readonly bool _exitProcessOnConnectionLoss;
-    private readonly SemaphoreSlim _lock = new(1, 1);
-
-    private Stream? _stream;
-    private ClientWebSocket? _clientWebSocket;
-    private bool _disposed;
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="DotnetTestWebSocketClient"/> class for the primary data
-    /// channel (exits the process on connection loss).
-    /// </summary>
-    /// <param name="endpoint">
-    /// The loopback WebSocket endpoint (e.g. <c>ws://127.0.0.1:12345/dotnettest</c>) that the SDK/gateway is
-    /// already listening on. Resolved and supplied by the SDK, mirroring how the named-pipe transport receives an
-    /// already-resolved OS pipe name rather than computing one itself.
-    /// </param>
-    /// <param name="authToken">
-    /// A per-run secret the SDK generated for this connection. It is never logged; see
-    /// <see cref="BuildAuthenticatedUri(Uri, string)"/> for how it is transmitted.
-    /// </param>
-    /// <param name="environment">The environment abstraction used for process-exit on connection loss.</param>
-    public DotnetTestWebSocketClient(Uri endpoint, string authToken, IEnvironment environment)
-        : this(endpoint, authToken, environment, exitProcessOnConnectionLoss: true)
-    {
-    }
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="DotnetTestWebSocketClient"/> class.
-    /// </summary>
-    /// <param name="endpoint">
-    /// The loopback WebSocket endpoint (e.g. <c>ws://127.0.0.1:12345/dotnettest</c>) that the SDK/gateway is
-    /// already listening on. Resolved and supplied by the SDK, mirroring how the named-pipe transport receives an
-    /// already-resolved OS pipe name rather than computing one itself.
-    /// </param>
-    /// <param name="authToken">
-    /// A per-run secret the SDK generated for this connection. It is never logged; see
-    /// <see cref="BuildAuthenticatedUri(Uri, string)"/> for how it is transmitted.
-    /// </param>
-    /// <param name="environment">The environment abstraction used for process-exit on connection loss.</param>
-    /// <param name="exitProcessOnConnectionLoss">
-    /// See <see cref="NamedPipeClient(string, IEnvironment, bool)"/> for the semantics; the primary data channel
-    /// uses <see langword="true"/>, auxiliary channels use <see langword="false"/>.
-    /// </param>
-    public DotnetTestWebSocketClient(Uri endpoint, string authToken, IEnvironment environment, bool exitProcessOnConnectionLoss)
-    {
-        _endpoint = endpoint;
-        _authToken = authToken;
-        _environment = environment;
-        _exitProcessOnConnectionLoss = exitProcessOnConnectionLoss;
-    }
-
-    public bool IsConnected => _stream is not null;
-
-    public async Task ConnectAsync(CancellationToken cancellationToken)
-    {
-        Uri authenticatedEndpoint = BuildAuthenticatedUri(_endpoint, _authToken);
-
-#if NET7_0_OR_GREATER
-        if (OperatingSystem.IsBrowser())
-        {
-            _stream = await BrowserWebSocketDuplexStream.ConnectAsync(authenticatedEndpoint, cancellationToken).ConfigureAwait(false);
-            return;
-        }
-#endif
-        var clientWebSocket = new ClientWebSocket();
-        try
-        {
-            await clientWebSocket.ConnectAsync(authenticatedEndpoint, cancellationToken).ConfigureAwait(false);
-        }
-        catch
-        {
-            clientWebSocket.Dispose();
-            throw;
-        }
-
-        _clientWebSocket = clientWebSocket;
-        _stream = new ClientWebSocketDuplexStream(clientWebSocket);
-    }
-
-    /// <summary>
-    /// Appends the per-run authentication token to <paramref name="endpoint"/> as a query-string parameter.
-    /// </summary>
-    /// <remarks>
-    /// The browser's native <c>WebSocket</c> constructor only accepts a URL and an optional subprotocol list - it
-    /// cannot set arbitrary request headers on the upgrade handshake - so a bearer header is not an option for the
-    /// browser transport. A query-string token is the same approach ASP.NET Core SignalR uses for its WebSocket
-    /// transport for the identical reason. This is also why CORS cannot serve as authentication here: CORS governs
-    /// which origins may *read* a cross-origin response, not who may *open* a WebSocket connection in the first
-    /// place, so without an explicit token any process that can reach the loopback port could connect. Callers must
-    /// never log the returned <see cref="Uri"/> verbatim (or any log line derived from it) since it carries the
-    /// secret - diagnostics should log only <see cref="Uri.Host"/>/<see cref="Uri.Port"/>/<see cref="Uri.AbsolutePath"/>.
-    /// </remarks>
-    internal static Uri BuildAuthenticatedUri(Uri endpoint, string token)
-    {
-        string tokenFragment = $"dotnetTestToken={Uri.EscapeDataString(token)}";
-        string original = endpoint.OriginalString;
-        int fragmentIndex = original.IndexOf('#');
-        string beforeFragment = fragmentIndex >= 0 ? original[..fragmentIndex] : original;
-        string fragment = fragmentIndex >= 0 ? original[fragmentIndex..] : string.Empty;
-        string separator = beforeFragment.Contains('?') ? "&" : "?";
-        return new Uri($"{beforeFragment}{separator}{tokenFragment}{fragment}", UriKind.Absolute);
-    }
-
-    public async Task<TResponse> RequestReplyAsync<TRequest, TResponse>(TRequest request, CancellationToken cancellationToken)
-        where TRequest : IRequest
-        where TResponse : IResponse
-    {
-        RoslynDebug.Assert(_stream is not null);
-
-        await _lock.WaitAsync(cancellationToken).ConfigureAwait(false);
-        try
-        {
-            INamedPipeSerializer requestSerializer = GetSerializer(typeof(TRequest));
-
-            try
-            {
-                await WriteMessageAsync(_stream, requestSerializer, request!, cancellationToken).ConfigureAwait(false);
-            }
-            catch (Exception ex) when (ex is IOException or ObjectDisposedException or WebSocketException)
-            {
-                // The peer disconnected while we were writing the request. Mirror NamedPipeClient's handling: if
-                // we cannot deliver the request there's no way to recover, so exit abnormally instead of
-                // surfacing a raw transport error to the caller (for the primary data channel).
-                if (!_exitProcessOnConnectionLoss)
-                {
-                    throw;
-                }
-
-                _environment.Exit((int)ExitCode.GenericFailure);
-                throw;
-            }
-
-            object? response;
-            try
-            {
-                response = await ReadNextMessageAsync(_stream, cancellationToken).ConfigureAwait(false);
-            }
-            catch (Exception ex) when (ex is IOException or ObjectDisposedException or WebSocketException)
-            {
-                // Unlike a named pipe (which reports a clean disconnect as a 0-byte read, i.e. a null response
-                // below), an abrupt WebSocket disconnect - e.g. the peer's process being killed mid-response,
-                // before it can complete the WebSocket close handshake - surfaces here as a thrown exception
-                // instead of a null result. Route it through the same connection-loss handling as a null
-                // response so both failure shapes are indistinguishable to the caller.
-                await HandleMissingResponseAsync(ex).ConfigureAwait(false);
-                throw; // Unreachable: HandleMissingResponseAsync always throws or terminates the process.
-            }
-
-            if (response is null)
-            {
-                await HandleMissingResponseAsync(cause: null).ConfigureAwait(false);
-            }
-
-            return (TResponse)response!;
-        }
-        finally
-        {
-            _lock.Release();
-        }
-    }
-
-    /// <summary>
-    /// Reacts to the transport being closed by the peer before a response was received - whether observed as a
-    /// null/EOF read or as a thrown transport exception (see the two callers in
-    /// <see cref="RequestReplyAsync{TRequest, TResponse}"/>). Mirrors <see cref="NamedPipeClient"/>'s identical
-    /// connection-loss policy: when the primary data channel (<c>exitProcessOnConnectionLoss: true</c>) loses its
-    /// peer there is no way to recover, so the process exits abnormally after a best-effort diagnostic; an
-    /// auxiliary channel (<c>exitProcessOnConnectionLoss: false</c>) instead always throws so the caller can react
-    /// cooperatively.
-    /// </summary>
-    /// <remarks>Never returns normally: either throws, or terminates the process via <c>_environment.Exit</c>.</remarks>
-    private async Task HandleMissingResponseAsync(Exception? cause)
-    {
-        if (!_exitProcessOnConnectionLoss)
-        {
-            throw new IOException("The WebSocket transport was closed by the peer before a response was received.", cause);
-        }
-
-        // Surface a diagnostic on stderr so the user has a chance to understand why this process is exiting. We
-        // deliberately use Console.Error (and not stdout) to avoid corrupting any machine-readable output that
-        // may be flowing through stdout.
-        try
-        {
-            await Console.Error.WriteLineAsync($"[DotnetTestWebSocketClient] The WebSocket transport was closed by the peer before a response was received. The peer process likely exited or was killed. Terminating with exit code {(int)ExitCode.GenericFailure}.").ConfigureAwait(false);
-        }
-        catch (Exception ex) when (ex is IOException or ObjectDisposedException or InvalidOperationException or NotSupportedException or ArgumentException or OperationCanceledException)
-        {
-            // Best-effort diagnostic only; never let logging failures shadow the original problem.
-        }
-
-        _environment.Exit((int)ExitCode.GenericFailure);
-
-        // _environment.Exit normally terminates the process and never returns. Guard against alternate
-        // IEnvironment implementations (e.g. tests) that don't terminate by throwing explicitly.
-        throw new InvalidOperationException("The WebSocket transport was closed by the peer before a response was received.", cause);
-    }
-
-    public void Dispose()
-    {
-        if (_disposed)
-        {
-            return;
-        }
-
-        _disposed = true;
-        _lock.Dispose();
-        DisposeBuffers();
-        _stream?.Dispose();
-        _clientWebSocket?.Dispose();
-    }
-}
diff --git a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/BrowserWasmExecutionTests.cs b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/BrowserWasmExecutionTests.cs
index 241b4eb3d0..fbef99fc27 100644
--- a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/BrowserWasmExecutionTests.cs
+++ b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/BrowserWasmExecutionTests.cs
@@ -1,8 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
-using System.Globalization;
-
 namespace Microsoft.Testing.Platform.Acceptance.IntegrationTests;
 
 /// <summary>
@@ -225,215 +223,6 @@ public void ExistingAssemblyTest()
 // Set exitCode rather than calling process.exit(): process.exit() can terminate Node before
 // redirected stdout/stderr has flushed, which would truncate the MTP summary this test asserts on.
 process.exitCode = exitCode;
-""";
-
-    private const string NodeWebSocketGatewayRunnerSource = """
-import { createHash } from 'node:crypto';
-import { createServer } from 'node:net';
-import { dotnet } from './_framework/dotnet.js';
-
-const token = 'browser-transport-secret';
-let authenticated = false;
-let transport = null;
-let requestCount = 0;
-let disconnected = false;
-
-function websocketFrame(payload) {
-    if (payload.length < 126) {
-        return Buffer.concat([Buffer.from([0x82, payload.length]), payload]);
-    }
-
-    const header = Buffer.alloc(4);
-    header[0] = 0x82;
-    header[1] = 126;
-    header.writeUInt16BE(payload.length, 2);
-    return Buffer.concat([header, payload]);
-}
-
-function protocolFrame(serializerId, body = Buffer.alloc(0)) {
-    const frame = Buffer.alloc(8 + body.length);
-    frame.writeInt32LE(4 + body.length, 0);
-    frame.writeInt32LE(serializerId, 4);
-    body.copy(frame, 8);
-    return frame;
-}
-
-function handshakeReply() {
-    const version = Buffer.from('1.5.0');
-    const body = Buffer.alloc(2 + 1 + 4 + version.length);
-    body.writeUInt16LE(1, 0);
-    body[2] = 4;
-    body.writeInt32LE(version.length, 3);
-    version.copy(body, 7);
-    return protocolFrame(9, body);
-}
-
-function readHandshakeTransport(body) {
-    let offset = 0;
-    const count = body.readUInt16LE(offset);
-    offset += 2;
-    for (let i = 0; i < count; i++) {
-        const key = body[offset++];
-        const length = body.readInt32LE(offset);
-        offset += 4;
-        const value = body.subarray(offset, offset + length).toString('utf8');
-        offset += length;
-        if (key === 16) {
-            return value;
-        }
-    }
-
-    return null;
-}
-
-function consumeFrames(socket, state) {
-    while (state.buffer.length >= 2) {
-        const first = state.buffer[0];
-        const second = state.buffer[1];
-        let length = second & 0x7f;
-        let offset = 2;
-        if (length === 126) {
-            if (state.buffer.length < 4) return;
-            length = state.buffer.readUInt16BE(2);
-            offset = 4;
-        } else if (length === 127) {
-            if (state.buffer.length < 10) return;
-            length = Number(state.buffer.readBigUInt64BE(2));
-            offset = 10;
-        }
-
-        const masked = (second & 0x80) !== 0;
-        const maskLength = masked ? 4 : 0;
-        if (state.buffer.length < offset + maskLength + length) return;
-
-        let payload = Buffer.from(state.buffer.subarray(offset + maskLength, offset + maskLength + length));
-        if (masked) {
-            const mask = state.buffer.subarray(offset, offset + 4);
-            for (let i = 0; i < payload.length; i++) payload[i] ^= mask[i % 4];
-        }
-
-        state.buffer = state.buffer.subarray(offset + maskLength + length);
-        const opcode = first & 0x0f;
-        if (opcode === 8) {
-            disconnected = true;
-            socket.end();
-            continue;
-        }
-
-        if (opcode !== 2) continue;
-        requestCount++;
-        const serializerId = payload.readInt32LE(4);
-        if (serializerId === 9) {
-            transport = readHandshakeTransport(payload.subarray(8));
-            socket.write(websocketFrame(Buffer.alloc(0)));
-            socket.write(websocketFrame(handshakeReply()));
-        } else {
-            // All post-handshake request/reply messages emitted by this no-op passing framework expect
-            // VoidResponse, matching FakeDotnetTestSdk's named-pipe harness.
-            socket.write(websocketFrame(protocolFrame(0)));
-        }
-    }
-}
-
-const server = createServer(socket => {
-    const state = { upgraded: false, buffer: Buffer.alloc(0) };
-    socket.on('end', () => { disconnected = true; });
-    socket.on('close', () => { disconnected = true; });
-    socket.on('data', chunk => {
-        state.buffer = Buffer.concat([state.buffer, chunk]);
-        if (!state.upgraded) {
-            const end = state.buffer.indexOf('\r\n\r\n');
-            if (end < 0) return;
-            const request = state.buffer.subarray(0, end).toString('utf8');
-            authenticated = request.includes(`dotnetTestToken=${token}`);
-            const key = /^Sec-WebSocket-Key:\s*(.+)$/mi.exec(request)?.[1]?.trim();
-            const accept = createHash('sha1').update(key + '258EAFA5-E914-47DA-95CA-C5AB0DC85B11').digest('base64');
-            socket.write(
-                'HTTP/1.1 101 Switching Protocols\r\n' +
-                'Upgrade: websocket\r\n' +
-                'Connection: Upgrade\r\n' +
-                `Sec-WebSocket-Accept: ${accept}\r\n\r\n`);
-            state.buffer = state.buffer.subarray(end + 4);
-            state.upgraded = true;
-        }
-
-        consumeFrames(socket, state);
-    });
-});
-
-await new Promise(resolve => server.listen(0, '127.0.0.1', resolve));
-const port = server.address().port;
-const { runMain } = await dotnet.withApplicationArguments(
-    '--server', 'dotnettestcli',
-    '--dotnet-test-transport', 'websocket',
-    '--dotnet-test-websocket-endpoint', `ws://127.0.0.1:${port}/dotnettest`,
-    '--dotnet-test-websocket-token', token).create();
-const exitCode = await runMain();
-await new Promise(resolve => setTimeout(resolve, 1000));
-server.close();
-
-console.log(`BROWSER_WEBSOCKET_AUTHENTICATED=${authenticated}`);
-console.log(`BROWSER_WEBSOCKET_TRANSPORT=${transport}`);
-console.log(`BROWSER_WEBSOCKET_REQUESTS=${requestCount}`);
-console.log(`BROWSER_WEBSOCKET_DISCONNECTED=${disconnected}`);
-process.exitCode = exitCode;
-""";
-
-    private const string NodeStalledWebSocketRunnerSource = """
-import { createServer } from 'node:net';
-import { dotnet } from './_framework/dotnet.js';
-
-const sockets = new Set();
-const server = createServer(socket => {
-    sockets.add(socket);
-    socket.on('close', () => sockets.delete(socket));
-    // Deliberately never complete the HTTP upgrade. BrowserWebSocketDuplexStream.ConnectAsync must still
-    // observe its .NET cancellation token while the browser-native WebSocket remains in CONNECTING state.
-});
-await new Promise(resolve => server.listen(0, '127.0.0.1', resolve));
-const port = server.address().port;
-const { runMain } = await dotnet.withApplicationArguments('connect-cancel', `ws://127.0.0.1:${port}/stalled`).create();
-const exitCode = await runMain();
-for (const socket of sockets) socket.destroy();
-server.close();
-process.exitCode = exitCode;
-""";
-
-    private const string NodeWebSocketIoCancellationRunnerSource = """
-import { createHash } from 'node:crypto';
-import { createServer } from 'node:net';
-import { dotnet } from './_framework/dotnet.js';
-
-function websocketFrame(payload) {
-    return Buffer.concat([Buffer.from([0x82, payload.length]), payload]);
-}
-
-const server = createServer(socket => {
-    let buffer = Buffer.alloc(0);
-    socket.on('data', chunk => {
-        buffer = Buffer.concat([buffer, chunk]);
-        const end = buffer.indexOf('\r\n\r\n');
-        if (end < 0) return;
-        const request = buffer.subarray(0, end).toString('utf8');
-        const key = /^Sec-WebSocket-Key:\s*(.+)$/mi.exec(request)?.[1]?.trim();
-        const accept = createHash('sha1').update(key + '258EAFA5-E914-47DA-95CA-C5AB0DC85B11').digest('base64');
-        socket.write(
-            'HTTP/1.1 101 Switching Protocols\r\n' +
-            'Upgrade: websocket\r\n' +
-            'Connection: Upgrade\r\n' +
-            `Sec-WebSocket-Accept: ${accept}\r\n\r\n`);
-        socket.removeAllListeners('data');
-        setTimeout(() => socket.write(websocketFrame(Buffer.from('after-cancel'))), 750);
-        setTimeout(() => socket.destroy(), 1500);
-    });
-});
-
-await new Promise(resolve => server.listen(0, '127.0.0.1', resolve));
-const port = server.address().port;
-const { runMain } = await dotnet.withApplicationArguments(`ws://127.0.0.1:${port}/cancellation`).create();
-const exitCode = await runMain();
-server.close();
-process.exitCode = exitCode;
 """;
 
     // The runsettings XML (declaring an <EnvironmentVariables> section) that the run-settings validation
@@ -589,115 +378,6 @@ public async Task ExecuteRequestAsync(ExecuteRequestContext context)
         context.Complete();
     }
 }
-""";
-
-    private const string WebSocketCancellationSourceCode = """
-#file BrowserWebSocketCancellationProject.csproj
-<Project Sdk="Microsoft.NET.Sdk">
-  <PropertyGroup>
-    <TargetFramework>$TargetFramework$</TargetFramework>
-    <RuntimeIdentifier>$BrowserRid$</RuntimeIdentifier>
-    <OutputType>Exe</OutputType>
-    <SelfContained>true</SelfContained>
-    <Nullable>enable</Nullable>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <WasmMainJSPath>main.js</WasmMainJSPath>
-    <WasmBuildNative>false</WasmBuildNative>
-    <PublishTrimmed>false</PublishTrimmed>
-    <NoWarn>$(NoWarn);NETSDK1201</NoWarn>
-  </PropertyGroup>
-  <ItemGroup>
-    <PackageReference Include="Microsoft.Testing.Platform" Version="$MicrosoftTestingPlatformVersion$" />
-  </ItemGroup>
-</Project>
-
-#file main.js
-import { dotnet } from './_framework/dotnet.js';
-const { runMain } = await dotnet.withApplicationArgumentsFromQuery().create();
-globalThis.mtpExitCode = await runMain();
-
-#file Program.cs
-using System.Reflection;
-using Microsoft.Testing.Platform.Builder;
-
-Type streamType = typeof(TestApplication).Assembly.GetType("Microsoft.Testing.Platform.IPC.BrowserWebSocketDuplexStream", throwOnError: true)!;
-MethodInfo connectAsync = streamType.GetMethod("ConnectAsync", BindingFlags.Public | BindingFlags.Static)!;
-if (args[0] == "connect-cancel")
-{
-    using CancellationTokenSource cancellationTokenSource = new(TimeSpan.FromMilliseconds(250));
-    Task connectTask = (Task)connectAsync.Invoke(null, [new Uri(args[1]), cancellationTokenSource.Token])!;
-    try
-    {
-        await connectTask;
-        Console.Error.WriteLine("Browser WebSocket connection unexpectedly completed.");
-        return 1;
-    }
-    catch (OperationCanceledException) when (cancellationTokenSource.IsCancellationRequested)
-    {
-        Console.WriteLine("BROWSER_WEBSOCKET_CONNECT_CANCELLED=true");
-        MethodInfo pendingOpenCount = streamType.GetMethod("GetPendingOpenCount", BindingFlags.NonPublic | BindingFlags.Static)!;
-        Console.WriteLine($"BROWSER_WEBSOCKET_PENDING_OPEN_COUNT={pendingOpenCount.Invoke(null, null)}");
-        return 0;
-    }
-}
-
-Task successfulConnectTask = (Task)connectAsync.Invoke(null, [new Uri(args[0]), CancellationToken.None])!;
-await successfulConnectTask;
-using Stream stream = (Stream)successfulConnectTask.GetType().GetProperty("Result")!.GetValue(successfulConnectTask)!;
-
-byte[] buffer = new byte[32];
-using CancellationTokenSource preCancelledRead = new();
-preCancelledRead.Cancel();
-try
-{
-    await stream.ReadAsync(buffer, 0, buffer.Length, preCancelledRead.Token);
-    Console.Error.WriteLine("Browser WebSocket read unexpectedly ignored pre-cancellation.");
-    return 6;
-}
-catch (OperationCanceledException)
-{
-    Console.WriteLine("BROWSER_WEBSOCKET_PRE_CANCELLED_READ=true");
-}
-
-Task<int> zeroCountRead = stream.ReadAsync(buffer, 0, 0, CancellationToken.None);
-if (await Task.WhenAny(zeroCountRead, Task.Delay(100)) != zeroCountRead || await zeroCountRead != 0)
-{
-    Console.Error.WriteLine("Browser WebSocket zero-count read did not complete immediately.");
-    return 4;
-}
-Console.WriteLine("BROWSER_WEBSOCKET_ZERO_COUNT_READ=0");
-
-using (CancellationTokenSource readCancellation = new(TimeSpan.FromMilliseconds(100)))
-{
-    try
-    {
-        await stream.ReadAsync(buffer, 0, buffer.Length, readCancellation.Token);
-        Console.Error.WriteLine("Browser WebSocket read unexpectedly completed before cancellation.");
-        return 2;
-    }
-    catch (OperationCanceledException) when (readCancellation.IsCancellationRequested)
-    {
-        Console.WriteLine("BROWSER_WEBSOCKET_READ_CANCELLED=true");
-    }
-}
-
-int read = await stream.ReadAsync(buffer, 0, buffer.Length, CancellationToken.None);
-Console.WriteLine($"BROWSER_WEBSOCKET_MESSAGE_AFTER_CANCEL={System.Text.Encoding.UTF8.GetString(buffer, 0, read)}");
-
-using CancellationTokenSource writeCancellation = new();
-writeCancellation.Cancel();
-try
-{
-    await stream.WriteAsync(new byte[] { 1, 2, 3 }, 0, 3, writeCancellation.Token);
-    Console.Error.WriteLine("Browser WebSocket write unexpectedly ignored pre-cancellation.");
-    return 3;
-}
-catch (OperationCanceledException)
-{
-    Console.WriteLine("BROWSER_WEBSOCKET_WRITE_CANCELLED=true");
-}
-
-return 0;
 """;
 
     public TestContext TestContext { get; set; } = null!;
@@ -877,79 +557,6 @@ public async Task BrowserWasmExecution_FrameworkWarningReachesNode()
             $"Expected exit code {(int)ExitCode.Success} (Success) for the warning asset.{Environment.NewLine}{combined}");
     }
 
-    [TestMethod]
-    public async Task BrowserWasmExecution_DotnetTestWebSocketTransport_RunsProtocolSession()
-    {
-        string? node = WasmRuntime.LocateNode();
-        if (node is null)
-        {
-            Assert.Inconclusive(WasmRuntime.NodeUnavailableMessage);
-            return;
-        }
-
-        using TestAsset generator = await GenerateBrowserWasmWarningAssetAsync();
-
-        (int exitCode, _, _, string combined) = await PublishAndRunUnderNodeAsync(generator, node, NodeWebSocketGatewayRunnerSource, enableWebSocket: true);
-
-        Assert.AreEqual(
-            (int)ExitCode.Success,
-            exitCode,
-            $"Expected the browser-wasm WebSocket protocol run to succeed.{Environment.NewLine}{combined}");
-        Assert.Contains("BROWSER_WEBSOCKET_AUTHENTICATED=true", combined);
-        Assert.Contains("BROWSER_WEBSOCKET_TRANSPORT=WebSocket", combined);
-        Assert.IsTrue(
-            TryReadMarkerInt(combined, "BROWSER_WEBSOCKET_REQUESTS=", out int requestCount) && requestCount > 1,
-            $"Expected the gateway to receive the handshake plus protocol traffic.{Environment.NewLine}{combined}");
-        Assert.Contains("BROWSER_WEBSOCKET_DISCONNECTED=true", combined);
-    }
-
-    [TestMethod]
-    public async Task BrowserWasmExecution_DotnetTestWebSocketConnect_HonorsCancellationWhileUpgradeIsStalled()
-    {
-        string? node = WasmRuntime.LocateNode();
-        if (node is null)
-        {
-            Assert.Inconclusive(WasmRuntime.NodeUnavailableMessage);
-            return;
-        }
-
-        using TestAsset generator = await GenerateBrowserWasmWebSocketCancellationAssetAsync();
-
-        (int exitCode, _, _, string combined) = await PublishAndRunUnderNodeAsync(generator, node, NodeStalledWebSocketRunnerSource, enableWebSocket: true);
-
-        Assert.AreEqual(
-            (int)ExitCode.Success,
-            exitCode,
-            $"Expected a stalled browser WebSocket upgrade to be cancelled cleanly.{Environment.NewLine}{combined}");
-        Assert.Contains("BROWSER_WEBSOCKET_CONNECT_CANCELLED=true", combined);
-        Assert.Contains("BROWSER_WEBSOCKET_PENDING_OPEN_COUNT=0", combined);
-    }
-
-    [TestMethod]
-    public async Task BrowserWasmExecution_DotnetTestWebSocketReadAndWrite_HonorCancellationWithoutLosingNextMessage()
-    {
-        string? node = WasmRuntime.LocateNode();
-        if (node is null)
-        {
-            Assert.Inconclusive(WasmRuntime.NodeUnavailableMessage);
-            return;
-        }
-
-        using TestAsset generator = await GenerateBrowserWasmWebSocketCancellationAssetAsync();
-
-        (int exitCode, _, _, string combined) = await PublishAndRunUnderNodeAsync(generator, node, NodeWebSocketIoCancellationRunnerSource, enableWebSocket: true);
-
-        Assert.AreEqual(
-            (int)ExitCode.Success,
-            exitCode,
-            $"Expected browser WebSocket read/write cancellation to complete cleanly.{Environment.NewLine}{combined}");
-        Assert.Contains("BROWSER_WEBSOCKET_READ_CANCELLED=true", combined);
-        Assert.Contains("BROWSER_WEBSOCKET_PRE_CANCELLED_READ=true", combined);
-        Assert.Contains("BROWSER_WEBSOCKET_MESSAGE_AFTER_CANCEL=after-cancel", combined);
-        Assert.Contains("BROWSER_WEBSOCKET_WRITE_CANCELLED=true", combined);
-        Assert.Contains("BROWSER_WEBSOCKET_ZERO_COUNT_READ=0", combined);
-    }
-
     [TestMethod]
     public async Task BrowserWasmExecution_RunSettingsEnvironmentVariables_FailsWithClearDiagnostic()
     {
@@ -1012,11 +619,7 @@ public async Task BrowserWasmExecution_RunSettingsEnvironmentVariables_FailsWith
     // Publishes the generated browser-wasm asset, staging + booting it under Node. Only a missing
     // 'wasm-tools' workload is an acceptable skip (Inconclusive); any other publish failure is a real
     // regression and fails the test. Returns the process exit code plus captured stdout/stderr.
-    private async Task<(int ExitCode, string Output, string Error, string Combined)> PublishAndRunUnderNodeAsync(
-        TestAsset generator,
-        string node,
-        string runnerSource = NodeRunnerSource,
-        bool enableWebSocket = false)
+    private async Task<(int ExitCode, string Output, string Error, string Combined)> PublishAndRunUnderNodeAsync(TestAsset generator, string node)
     {
         DotnetMuxerResult publishResult = await WasmRuntime.PublishForBrowserAsync(
             generator.TargetAssetPath, TargetFramework, TestContext.CancellationToken);
@@ -1034,22 +637,7 @@ public async Task BrowserWasmExecution_RunSettingsEnvironmentVariables_FailsWith
             Directory.Exists(appBundle),
             $"Expected the browser-wasm AppBundle directory at '{appBundle}'.");
 
-        return await WasmRuntime.RunUnderNodeAsync(node, appBundle, runnerSource, TestContext.CancellationToken, enableWebSocket);
-    }
-
-    private static bool TryReadMarkerInt(string output, string marker, out int value)
-    {
-        int markerIndex = output.IndexOf(marker, StringComparison.Ordinal);
-        if (markerIndex < 0)
-        {
-            value = 0;
-            return false;
-        }
-
-        int valueStart = markerIndex + marker.Length;
-        int valueEnd = output.IndexOfAny(['\r', '\n'], valueStart);
-        string text = valueEnd < 0 ? output[valueStart..] : output[valueStart..valueEnd];
-        return int.TryParse(text, CultureInfo.InvariantCulture, out value);
+        return await WasmRuntime.RunUnderNodeAsync(node, appBundle, NodeRunnerSource, TestContext.CancellationToken);
     }
 
     private Task<TestAsset> GenerateBrowserWasmAssetAsync()
@@ -1070,14 +658,6 @@ private Task<TestAsset> GenerateBrowserWasmWarningAssetAsync()
                 .PatchCodeWithReplace("$ErrorText$", ErrorText)
                 .PatchCodeWithReplace("$MicrosoftTestingPlatformVersion$", MicrosoftTestingPlatformVersion));
 
-    private Task<TestAsset> GenerateBrowserWasmWebSocketCancellationAssetAsync()
-        => TestAsset.GenerateAssetAsync(
-            "BrowserWebSocketCancellationProject",
-            WebSocketCancellationSourceCode
-                .PatchCodeWithReplace("$TargetFramework$", TargetFramework)
-                .PatchCodeWithReplace("$BrowserRid$", WasmRuntime.BrowserRid)
-                .PatchCodeWithReplace("$MicrosoftTestingPlatformVersion$", MicrosoftTestingPlatformVersion));
-
     private Task<TestAsset> GenerateBrowserWasmCustomHostAssetAsync()
     {
         var versions = XDocument.Load(Path.Combine(RootFinder.Find(), "eng", "Versions.props"));
diff --git a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DotnetTestPipe/DotnetTestPipeBaselineTests.cs b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DotnetTestPipe/DotnetTestPipeBaselineTests.cs
index d64a6bb2b9..057bcbf7f8 100644
--- a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DotnetTestPipe/DotnetTestPipeBaselineTests.cs
+++ b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DotnetTestPipe/DotnetTestPipeBaselineTests.cs
@@ -25,13 +25,12 @@ public class DotnetTestPipeBaselineTests : AcceptanceTestBase<DotnetTestPipeBase
 
     public TestContext TestContext { get; set; } = null!;
 
-    // The test host (testfx) now advertises protocol 1.0.0 through 1.5.0. The 1.1.0 bump
+    // The test host (testfx) now advertises protocol 1.0.0 through 1.4.0. The 1.1.0 bump
     // signalled that TerminalOutputDevice is no longer plugged in under the pipe protocol (microsoft/testfx#7161
     // and dotnet/sdk#51615); 1.2.0 added AzureDevOpsLogMessage forwarding; 1.3.0 added generic DisplayMessage
-    // (warning/error) forwarding; 1.4.0 added the reverse server-control channel (server-initiated cancellation);
-    // 1.5.0 added the Transport handshake capability property (NamedPipe/WebSocket).
+    // (warning/error) forwarding; 1.4.0 added the reverse server-control channel (server-initiated cancellation).
     // This mirrors ProtocolConstants.SupportedVersions on the host side.
-    private const string HostAdvertisedProtocolVersions = "1.0.0;1.1.0;1.2.0;1.3.0;1.4.0;1.5.0";
+    private const string HostAdvertisedProtocolVersions = "1.0.0;1.1.0;1.2.0;1.3.0;1.4.0";
 
     [TestMethod]
     public async Task DotnetTestPipe_TestAppAdvertisesAllSupportedVersions_NegotiatesDownToV100WithOldSdk()
@@ -62,10 +61,6 @@ public async Task DotnetTestPipe_TestAppAdvertisesAllSupportedVersions_Negotiate
             "1",
             result.ReceivedHandshake[DotnetTestPipeProtocol.HandshakeProperties.AttemptNumber],
             "A non-retried test host should report attempt 1.");
-        Assert.AreEqual(
-            "NamedPipe",
-            result.ReceivedHandshake[DotnetTestPipeProtocol.HandshakeProperties.Transport],
-            "The legacy pipe path must identify its transport as NamedPipe.");
     }
 
     [TestMethod]
diff --git a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DotnetTestPipe/DotnetTestPipeProtocol.cs b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DotnetTestPipe/DotnetTestPipeProtocol.cs
index a869ae8b99..8e7049ce0e 100644
--- a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DotnetTestPipe/DotnetTestPipeProtocol.cs
+++ b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DotnetTestPipe/DotnetTestPipeProtocol.cs
@@ -64,7 +64,6 @@ public static class HandshakeProperties
         public const byte AttemptNumber = 13;
         public const byte SupportedPostProcessorKinds = 14;
         public const byte SupportedPostProcessorExtensionsLegacy = 15;
-        public const byte Transport = 16;
     }
 
     public static class ServerControlKinds
diff --git a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/HelpInfoAllExtensionsTests.cs b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/HelpInfoAllExtensionsTests.cs
index 84f32ee504..c6397aa222 100644
--- a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/HelpInfoAllExtensionsTests.cs
+++ b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/HelpInfoAllExtensionsTests.cs
@@ -317,18 +317,6 @@ Note that this is slowing down the test execution.
         Arity: 1
         Hidden: True
         Description: dotnet test pipe.
-      --dotnet-test-transport
-        Arity: 1
-        Hidden: True
-        Description: Pre-launch transport used to carry the 'dotnet test' pipe protocol. The available values are 'pipe' and 'websocket'. Defaults to 'pipe' (implied whenever only '--dotnet-test-pipe' is specified).
-      --dotnet-test-websocket-endpoint
-        Arity: 1
-        Hidden: True
-        Description: The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected.
-      --dotnet-test-websocket-token
-        Arity: 1
-        Hidden: True
-        Description: The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'.
       --exit-on-process-exit
         Arity: 1
         Hidden: False
diff --git a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/HelpInfoTests.cs b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/HelpInfoTests.cs
index 8ed140a529..dc8fd587b1 100644
--- a/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/HelpInfoTests.cs
+++ b/test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/HelpInfoTests.cs
@@ -211,18 +211,6 @@ Note that this is slowing down the test execution\.
         Arity: 1
         Hidden: True
         Description: dotnet test pipe\.
-      --dotnet-test-transport
-        Arity: 1
-        Hidden: True
-        Description: Pre-launch transport used to carry the 'dotnet test' pipe protocol\. The available values are 'pipe' and 'websocket'\. Defaults to 'pipe' \(implied whenever only '--dotnet-test-pipe' is specified\)\.
-      --dotnet-test-websocket-endpoint
-        Arity: 1
-        Hidden: True
-        Description: The WebSocket endpoint URI the test host connects to when '--dotnet-test-transport websocket' is selected\.
-      --dotnet-test-websocket-token
-        Arity: 1
-        Hidden: True
-        Description: The per-run authentication token the test host presents when connecting via '--dotnet-test-transport websocket'\.
       --exit-on-process-exit
         Arity: 1
         Hidden: False
diff --git a/test/UnitTests/Microsoft.Testing.Platform.DotnetTestProtocolContract.UnitTests/DotnetTestProtocolContractTests.cs b/test/UnitTests/Microsoft.Testing.Platform.DotnetTestProtocolContract.UnitTests/DotnetTestProtocolContractTests.cs
index b3349b029a..6dffe0cfdd 100644
--- a/test/UnitTests/Microsoft.Testing.Platform.DotnetTestProtocolContract.UnitTests/DotnetTestProtocolContractTests.cs
+++ b/test/UnitTests/Microsoft.Testing.Platform.DotnetTestProtocolContract.UnitTests/DotnetTestProtocolContractTests.cs
@@ -84,7 +84,6 @@ public void HandshakeMessagePropertyNames_AreStable()
             [HandshakeMessagePropertyNames.AttemptNumber] = nameof(HandshakeMessagePropertyNames.AttemptNumber),
             [HandshakeMessagePropertyNames.SupportedPostProcessorKinds] = nameof(HandshakeMessagePropertyNames.SupportedPostProcessorKinds),
             [HandshakeMessagePropertyNames.SupportedPostProcessorExtensionsLegacy] = nameof(HandshakeMessagePropertyNames.SupportedPostProcessorExtensionsLegacy),
-            [HandshakeMessagePropertyNames.Transport] = nameof(HandshakeMessagePropertyNames.Transport),
         };
 
         Assert.AreEqual(nameof(HandshakeMessagePropertyNames.PID), properties[0]);
@@ -103,16 +102,6 @@ public void HandshakeMessagePropertyNames_AreStable()
         Assert.AreEqual(nameof(HandshakeMessagePropertyNames.AttemptNumber), properties[13]);
         Assert.AreEqual(nameof(HandshakeMessagePropertyNames.SupportedPostProcessorKinds), properties[14]);
         Assert.AreEqual(nameof(HandshakeMessagePropertyNames.SupportedPostProcessorExtensionsLegacy), properties[15]);
-        Assert.AreEqual(nameof(HandshakeMessagePropertyNames.Transport), properties[16]);
-    }
-
-    [TestMethod]
-    public void HandshakeMessageTransportNames_AreStable()
-    {
-        string[] transports = [HandshakeMessageTransportNames.NamedPipe, HandshakeMessageTransportNames.WebSocket];
-
-        Assert.AreEqual("NamedPipe", transports[0]);
-        Assert.AreEqual("WebSocket", transports[1]);
     }
 
     [TestMethod]
@@ -170,6 +159,6 @@ public void ProtocolVersion_IsStable()
         // Indirect through a collection so the MSTest analyzer does not flag the comparison of a compile-time
         // constant as "always true" (MSTEST0032).
         string[] versions = [ProtocolConstants.SupportedVersions];
-        Assert.AreEqual("1.0.0;1.1.0;1.2.0;1.3.0;1.4.0;1.5.0", versions[0]);
+        Assert.AreEqual("1.0.0;1.1.0;1.2.0;1.3.0;1.4.0", versions[0]);
     }
 }
diff --git a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineArgumentsRedactorTests.cs b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineArgumentsRedactorTests.cs
deleted file mode 100644
index f2860c9009..0000000000
--- a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineArgumentsRedactorTests.cs
+++ /dev/null
@@ -1,200 +0,0 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-using Microsoft.Testing.Platform.CommandLine;
-
-namespace Microsoft.Testing.Platform.UnitTests.CommandLine;
-
-/// <summary>
-/// Tests for <see cref="CommandLineArgumentsRedactor"/>, which masks secret option values (currently
-/// <c>--dotnet-test-websocket-token</c>) before command-line arguments are written to the <c>--diagnostic</c>
-/// log. See <c>docs/mstest-runner-protocol/004-protocol-dotnet-test-pipe.md</c> §15.4.
-/// </summary>
-[TestClass]
-public sealed class CommandLineArgumentsRedactorTests
-{
-    [TestMethod]
-    public void Redact_WithNoArguments_ReturnsEmptyString()
-        => Assert.AreEqual(string.Empty, CommandLineArgumentsRedactor.Redact([]));
-
-    [TestMethod]
-    public void Redact_WithNoSensitiveOptions_ReturnsArgumentsUnchanged()
-    {
-        string[] args = ["--server", "dotnettestcli", "--dotnet-test-pipe", "some-pipe-name", "--diagnostic"];
-
-        Assert.AreEqual("--server dotnettestcli --dotnet-test-pipe some-pipe-name --diagnostic", CommandLineArgumentsRedactor.Redact(args));
-    }
-
-    [TestMethod]
-    public void Redact_WithSpaceSeparatedTokenValue_MasksValueAndKeepsOptionName()
-    {
-        string[] args = ["--server", "dotnettestcli", "--dotnet-test-websocket-token", "s3cr3t-token-value", "--dotnet-test-websocket-endpoint", "ws://127.0.0.1:5000/dotnettest"];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("s3cr3t-token-value", result);
-        Assert.Contains("--dotnet-test-websocket-token ***REDACTED***", result);
-        Assert.AreEqual("--server dotnettestcli --dotnet-test-websocket-token ***REDACTED*** --dotnet-test-websocket-endpoint ws://127.0.0.1:5000/dotnettest", result);
-    }
-
-    [TestMethod]
-    [DataRow('=')]
-    [DataRow(':')]
-    public void Redact_WithInlineDelimitedTokenValue_MasksValueOnly(char delimiter)
-    {
-        string[] args = [$"--dotnet-test-websocket-token{delimiter}s3cr3t-token-value"];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("s3cr3t-token-value", result);
-        Assert.AreEqual($"--dotnet-test-websocket-token{delimiter}***REDACTED***", result);
-    }
-
-    [TestMethod]
-    public void Redact_IsCaseInsensitiveForOptionNameButPreservesOriginalCasing()
-    {
-        string[] args = ["--DOTNET-TEST-WEBSOCKET-TOKEN", "s3cr3t-token-value"];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("s3cr3t-token-value", result);
-        Assert.AreEqual("--DOTNET-TEST-WEBSOCKET-TOKEN ***REDACTED***", result);
-    }
-
-    [TestMethod]
-    public void Redact_WhenTokenOptionIsLastArgumentWithNoValue_DoesNotThrowAndLeavesOptionUnchanged()
-    {
-        string[] args = ["--server", "dotnettestcli", "--dotnet-test-websocket-token"];
-
-        Assert.AreEqual("--server dotnettestcli --dotnet-test-websocket-token", CommandLineArgumentsRedactor.Redact(args));
-    }
-
-    [TestMethod]
-    public void Redact_WhenTokenOptionIsRepeated_MasksEachOccurrenceIndependently()
-    {
-        string[] args = ["--dotnet-test-websocket-token", "first-secret", "--dotnet-test-websocket-token", "second-secret"];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("first-secret", result);
-        Assert.DoesNotContain("second-secret", result);
-        Assert.AreEqual("--dotnet-test-websocket-token ***REDACTED*** --dotnet-test-websocket-token ***REDACTED***", result);
-    }
-
-    [TestMethod]
-    public void Redact_WhenSpaceSeparatedTokenLooksLikeOption_MasksToken()
-    {
-        string[] args = ["--dotnet-test-websocket-token", "-secret", "--diagnostic"];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("-secret", result);
-        Assert.AreEqual("--dotnet-test-websocket-token ***REDACTED*** --diagnostic", result);
-    }
-
-    [TestMethod]
-    [DataRow("--dotnet-test-websocket-endpoint", " ")]
-    [DataRow("--dotnet-test-websocket-endpoint=", "=")]
-    public void Redact_WebSocketEndpoint_RemovesUserInfoQueryAndFragment(string option, string separator)
-    {
-        string[] args = separator == " "
-            ? [option, "ws://user:password@localhost:123/run?dotnetTestToken=secret#fragment"]
-            : [$"{option}ws://user:password@localhost:123/run?dotnetTestToken=secret#fragment"];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("user", result);
-        Assert.DoesNotContain("password", result);
-        Assert.DoesNotContain("secret", result);
-        Assert.DoesNotContain("fragment", result);
-        Assert.AreEqual($"--dotnet-test-websocket-endpoint{separator}ws://localhost:123/run", result);
-    }
-
-    [TestMethod]
-    public void Redact_WhenTokenValueIsMissingBeforeEndpoint_SanitizesEndpoint()
-    {
-        string[] args =
-        [
-            "--dotnet-test-websocket-token",
-            "--dotnet-test-websocket-endpoint",
-            "ws://localhost/run?key=secret",
-        ];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("secret", result);
-        Assert.AreEqual("--dotnet-test-websocket-token --dotnet-test-websocket-endpoint ws://localhost/run", result);
-    }
-
-    [TestMethod]
-    public void Redact_WhenEndpointHasExtraValues_SanitizesEveryValueUntilNextOption()
-    {
-        string[] args =
-        [
-            "--dotnet-test-websocket-endpoint",
-            "ws://localhost/a?token=one",
-            "ws://localhost/b?token=two",
-            "--diagnostic",
-        ];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("one", result);
-        Assert.DoesNotContain("two", result);
-        Assert.AreEqual("--dotnet-test-websocket-endpoint ws://localhost/a ws://localhost/b --diagnostic", result);
-    }
-
-    [TestMethod]
-    public void Redact_WhenInlineEndpointHasExtraValue_SanitizesExtraValueUntilNextOption()
-    {
-        string[] args =
-        [
-            "--dotnet-test-websocket-endpoint=ws://localhost/a?token=one",
-            "ws://localhost/b?token=two",
-            "--diagnostic",
-        ];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("one", result);
-        Assert.DoesNotContain("two", result);
-        Assert.AreEqual("--dotnet-test-websocket-endpoint=ws://localhost/a ws://localhost/b --diagnostic", result);
-    }
-
-    [TestMethod]
-    public void Redact_WhenInlineTokenHasExtraValue_RedactsExtraValueUntilNextOption()
-    {
-        string[] args = ["--dotnet-test-websocket-token=first", "second", "--diagnostic"];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("first", result);
-        Assert.DoesNotContain("second", result);
-        Assert.AreEqual("--dotnet-test-websocket-token=***REDACTED*** ***REDACTED*** --diagnostic", result);
-    }
-
-    [TestMethod]
-    public void Redact_WhenExtraStrayValueFollowsTokenOption_RedactsUntilNextOption()
-    {
-        // Defensive: even if a caller mistakenly supplies more than one token for the (ArgumentArity.ExactlyOne)
-        // option, no fragment of the secret should survive in diagnostics.
-        string[] args = ["--dotnet-test-websocket-token", "secret-part-one", "secret-part-two", "--diagnostic"];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("secret-part-one", result);
-        Assert.DoesNotContain("secret-part-two", result);
-        Assert.AreEqual("--dotnet-test-websocket-token ***REDACTED*** ***REDACTED*** --diagnostic", result);
-    }
-
-    [TestMethod]
-    public void Redact_WithSingleDashOption_IsRecognizedAsAnOption()
-    {
-        string[] args = ["-dotnet-test-websocket-token", "s3cr3t-token-value"];
-
-        string result = CommandLineArgumentsRedactor.Redact(args);
-
-        Assert.DoesNotContain("s3cr3t-token-value", result);
-        Assert.AreEqual("-dotnet-test-websocket-token ***REDACTED***", result);
-    }
-}
diff --git a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineHandlerTests.cs b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineHandlerTests.cs
index 44d07d4bcb..b8959be2b3 100644
--- a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineHandlerTests.cs
+++ b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineHandlerTests.cs
@@ -44,116 +44,6 @@ public async Task ParseAndValidateAsync_InvalidCommandLineArguments_ReturnsFalse
         Assert.Contains("Unexpected argument 'a'", result.ErrorMessage);
     }
 
-    [TestMethod]
-    public async Task ParseAndValidateAsync_InvalidWebSocketEndpoint_DoesNotExposeTokenInError()
-    {
-        string[] args =
-        [
-            "--server", "dotnettestcli",
-            "--dotnet-test-transport", "websocket",
-            "--dotnet-test-websocket-endpoint", "not-a-uri",
-            "--dotnet-test-websocket-token", "super-secret",
-        ];
-        CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
-
-        ValidationResult result = await CommandLineOptionsValidator.ValidateAsync(
-            parseResult,
-            _systemCommandLineOptionsProviders,
-            _extensionCommandLineOptionsProviders,
-            new Mock<ICommandLineOptions>().Object);
-
-        Assert.IsFalse(result.IsValid);
-        Assert.DoesNotContain("super-secret", result.ErrorMessage);
-        Assert.Contains("***REDACTED***", result.ErrorMessage);
-    }
-
-    [TestMethod]
-    public async Task ParseAndValidateAsync_ShortInvalidEndpoint_DoesNotCorruptValidationError()
-    {
-        string[] args =
-        [
-            "--server", "dotnettestcli",
-            "--dotnet-test-transport", "websocket",
-            "--dotnet-test-websocket-endpoint", "a",
-            "--dotnet-test-websocket-token", "secret",
-        ];
-        CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
-
-        ValidationResult result = await CommandLineOptionsValidator.ValidateAsync(
-            parseResult,
-            _systemCommandLineOptionsProviders,
-            _extensionCommandLineOptionsProviders,
-            new Mock<ICommandLineOptions>().Object);
-
-        Assert.IsFalse(result.IsValid);
-        Assert.Contains("requires an absolute", result.ErrorMessage);
-        Assert.DoesNotContain("***REDACTED***bsolute", result.ErrorMessage);
-    }
-
-    [TestMethod]
-    [DataRow("-super-secret")]
-    [DataRow("'super'secret'")]
-    [DataRow(" 'super'secret' ")]
-    public async Task ParseAndValidateAsync_InvalidTokenValue_DoesNotExposeTokenInError(string token)
-    {
-        string[] args = ["--dotnet-test-websocket-token", token];
-        CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
-
-        ValidationResult result = await CommandLineOptionsValidator.ValidateAsync(
-            parseResult,
-            _systemCommandLineOptionsProviders,
-            _extensionCommandLineOptionsProviders,
-            new Mock<ICommandLineOptions>().Object);
-
-        Assert.IsFalse(result.IsValid);
-        Assert.DoesNotContain("super-secret", result.ErrorMessage);
-        Assert.DoesNotContain("super'secret", result.ErrorMessage);
-        Assert.Contains("***REDACTED***", result.ErrorMessage);
-    }
-
-    [TestMethod]
-    [DataRow("")]
-    [DataRow(" ")]
-    public async Task ParseAndValidateAsync_EmptyToken_ReturnsValidationErrorWithoutThrowing(string token)
-    {
-        string[] args = ["--dotnet-test-websocket-token", token];
-        CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
-
-        ValidationResult result = await CommandLineOptionsValidator.ValidateAsync(
-            parseResult,
-            _systemCommandLineOptionsProviders,
-            _extensionCommandLineOptionsProviders,
-            new Mock<ICommandLineOptions>().Object);
-
-        Assert.IsFalse(result.IsValid);
-        Assert.Contains("non-empty", result.ErrorMessage);
-    }
-
-    [TestMethod]
-    public async Task ParseAndValidateAsync_ResponseFileToken_DoesNotExposeTokenInError()
-    {
-        string responseFile = Path.GetTempFileName();
-        try
-        {
-            File.WriteAllText(responseFile, "--dotnet-test-websocket-token -super-secret");
-            CommandLineParseResult parseResult = CommandLineParser.Parse([$"@{responseFile}"], new SystemEnvironment());
-
-            ValidationResult result = await CommandLineOptionsValidator.ValidateAsync(
-                parseResult,
-                _systemCommandLineOptionsProviders,
-                _extensionCommandLineOptionsProviders,
-                new Mock<ICommandLineOptions>().Object);
-
-            Assert.IsFalse(result.IsValid);
-            Assert.DoesNotContain("super-secret", result.ErrorMessage);
-            Assert.Contains("***REDACTED***", result.ErrorMessage);
-        }
-        finally
-        {
-            File.Delete(responseFile);
-        }
-    }
-
     [TestMethod]
     public async Task ParseAndValidateAsync_ValidArgumentWithColonFollowedByValidArgumentWithoutColon_ReturnsTrue()
     {
diff --git a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/PlatformCommandLineProviderTests.cs b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/PlatformCommandLineProviderTests.cs
index 1a6fc3f46d..f2395774e9 100644
--- a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/PlatformCommandLineProviderTests.cs
+++ b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/PlatformCommandLineProviderTests.cs
@@ -343,29 +343,13 @@ public async Task IsInvalid_When_Server_DotnetTestCli_Without_DotnetTestPipe(str
 
         ValidationResult validateOptionsResult = await provider.ValidateCommandLineOptionsAsync(new TestCommandLineOptions(options)).ConfigureAwait(false);
         Assert.IsFalse(validateOptionsResult.IsValid);
-        Assert.AreEqual(PlatformResources.PlatformCommandLineDotnetTestCliRequiresTransport, validateOptionsResult.ErrorMessage);
-    }
-
-    [TestMethod]
-    public async Task IsInvalid_When_Server_DotnetTestCli_With_ExplicitPipeTransport_Without_DotnetTestPipe()
-    {
-        var provider = new PlatformCommandLineProvider();
-        var options = new Dictionary<string, string[]>
-        {
-            { PlatformCommandLineProvider.ServerOptionKey, ["dotnettestcli"] },
-            { PlatformCommandLineProvider.DotNetTestTransportOptionKey, ["pipe"] },
-        };
-
-        ValidationResult result = await provider.ValidateCommandLineOptionsAsync(new TestCommandLineOptions(options)).ConfigureAwait(false);
-
-        Assert.IsFalse(result.IsValid);
         Assert.AreEqual(
             string.Format(
                 CultureInfo.InvariantCulture,
                 PlatformResources.PlatformCommandLineDotnetTestCliRequiresPipe,
                 PlatformCommandLineProvider.DotnetTestCliProtocolName,
                 PlatformCommandLineProvider.DotNetTestPipeOptionKey),
-            result.ErrorMessage);
+            validateOptionsResult.ErrorMessage);
     }
 
     [TestMethod]
@@ -394,207 +378,6 @@ public async Task IsValid_When_Server_NoArgument_Without_DotnetTestPipe()
         Assert.IsTrue(validateOptionsResult.IsValid);
     }
 
-    [TestMethod]
-    [DataRow("pipe")]
-    [DataRow("PIPE")]
-    [DataRow("websocket")]
-    [DataRow("WebSocket")]
-    public async Task IsValid_When_DotnetTestTransport_HasAcceptedArgument_AnyCasing(string argument)
-    {
-        var provider = new PlatformCommandLineProvider();
-        CommandLineOption option = provider.GetCommandLineOptions().First(x => x.Name == PlatformCommandLineProvider.DotNetTestTransportOptionKey);
-
-        ValidationResult validateOptionsResult = await provider.ValidateOptionArgumentsAsync(option, [argument]).ConfigureAwait(false);
-        Assert.IsTrue(validateOptionsResult.IsValid);
-    }
-
-    [TestMethod]
-    [DataRow("named-pipe")]
-    [DataRow("http")]
-    [DataRow("")]
-    public async Task IsInvalid_When_DotnetTestTransport_HasUnknownArgument(string argument)
-    {
-        var provider = new PlatformCommandLineProvider();
-        CommandLineOption option = provider.GetCommandLineOptions().First(x => x.Name == PlatformCommandLineProvider.DotNetTestTransportOptionKey);
-
-        ValidationResult validateOptionsResult = await provider.ValidateOptionArgumentsAsync(option, [argument]).ConfigureAwait(false);
-        Assert.IsFalse(validateOptionsResult.IsValid);
-        Assert.AreEqual(
-            string.Format(
-                CultureInfo.InvariantCulture,
-                PlatformResources.PlatformCommandLineDotnetTestTransportInvalidArgument,
-                argument,
-                "'pipe', 'websocket'"),
-            validateOptionsResult.ErrorMessage);
-    }
-
-    [TestMethod]
-    public async Task IsValid_When_Server_DotnetTestCli_With_WebSocketTransport_And_EndpointAndToken()
-    {
-        var provider = new PlatformCommandLineProvider();
-        var options = new Dictionary<string, string[]>
-        {
-            { PlatformCommandLineProvider.ServerOptionKey, ["dotnettestcli"] },
-            { PlatformCommandLineProvider.DotNetTestTransportOptionKey, ["websocket"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey, ["ws://127.0.0.1:5000/dotnettest"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketTokenOptionKey, ["some-token"] },
-        };
-
-        ValidationResult validateOptionsResult = await provider.ValidateCommandLineOptionsAsync(new TestCommandLineOptions(options)).ConfigureAwait(false);
-        Assert.IsTrue(validateOptionsResult.IsValid);
-    }
-
-    [TestMethod]
-    [DataRow(null)]
-    [DataRow("jsonrpc")]
-    public async Task IsInvalid_When_WebSocketOptions_AreUsedWithoutDotnetTestCliServer(string? serverProtocol)
-    {
-        var provider = new PlatformCommandLineProvider();
-        var options = new Dictionary<string, string[]>
-        {
-            { PlatformCommandLineProvider.DotNetTestTransportOptionKey, ["websocket"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey, ["ws://127.0.0.1:5000/dotnettest"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketTokenOptionKey, ["some-token"] },
-        };
-        if (serverProtocol is not null)
-        {
-            options.Add(PlatformCommandLineProvider.ServerOptionKey, [serverProtocol]);
-        }
-
-        ValidationResult result = await provider.ValidateCommandLineOptionsAsync(new TestCommandLineOptions(options)).ConfigureAwait(false);
-
-        Assert.IsFalse(result.IsValid);
-        Assert.AreEqual(PlatformResources.PlatformCommandLineDotnetTestOptionsRequireServer, result.ErrorMessage);
-    }
-
-    [TestMethod]
-    [DataRow("")]
-    [DataRow("not-a-uri")]
-    [DataRow("https://127.0.0.1:5000/dotnettest")]
-    [DataRow("ws:/dotnettest")]
-    [DataRow("ws://127.0.0.1:5000/dotnettest#fragment")]
-    [DataRow("ws://user:password@127.0.0.1:5000/dotnettest")]
-    public async Task IsInvalid_When_WebSocketEndpoint_IsNotAbsoluteWebSocketUriWithoutFragmentOrUserInfo(string endpoint)
-    {
-        var provider = new PlatformCommandLineProvider();
-        CommandLineOption option = provider.GetCommandLineOptions().First(x => x.Name == PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey);
-
-        ValidationResult result = await provider.ValidateOptionArgumentsAsync(option, [endpoint]).ConfigureAwait(false);
-
-        Assert.IsFalse(result.IsValid);
-        Assert.AreEqual(PlatformResources.PlatformCommandLineDotnetTestWebSocketEndpointInvalid, result.ErrorMessage);
-    }
-
-    [TestMethod]
-    [DataRow("ws://127.0.0.1:5000/dotnettest")]
-    [DataRow("wss://localhost/dotnettest?run=1")]
-    public async Task IsValid_When_WebSocketEndpoint_IsAbsoluteWebSocketUriWithoutFragment(string endpoint)
-    {
-        var provider = new PlatformCommandLineProvider();
-        CommandLineOption option = provider.GetCommandLineOptions().First(x => x.Name == PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey);
-
-        ValidationResult result = await provider.ValidateOptionArgumentsAsync(option, [endpoint]).ConfigureAwait(false);
-
-        Assert.IsTrue(result.IsValid);
-    }
-
-    [TestMethod]
-    [DataRow("")]
-    [DataRow(" ")]
-    public async Task IsInvalid_When_WebSocketToken_IsEmpty(string token)
-    {
-        var provider = new PlatformCommandLineProvider();
-        CommandLineOption option = provider.GetCommandLineOptions().First(x => x.Name == PlatformCommandLineProvider.DotNetTestWebSocketTokenOptionKey);
-
-        ValidationResult result = await provider.ValidateOptionArgumentsAsync(option, [token]).ConfigureAwait(false);
-
-        Assert.IsFalse(result.IsValid);
-        Assert.AreEqual(PlatformResources.PlatformCommandLineDotnetTestWebSocketTokenEmpty, result.ErrorMessage);
-    }
-
-    [TestMethod]
-    public async Task IsInvalid_When_Server_DotnetTestCli_With_WebSocketTransport_Missing_Endpoint()
-    {
-        var provider = new PlatformCommandLineProvider();
-        var options = new Dictionary<string, string[]>
-        {
-            { PlatformCommandLineProvider.ServerOptionKey, ["dotnettestcli"] },
-            { PlatformCommandLineProvider.DotNetTestTransportOptionKey, ["websocket"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketTokenOptionKey, ["some-token"] },
-        };
-
-        ValidationResult validateOptionsResult = await provider.ValidateCommandLineOptionsAsync(new TestCommandLineOptions(options)).ConfigureAwait(false);
-        Assert.IsFalse(validateOptionsResult.IsValid);
-        Assert.AreEqual(PlatformResources.PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken, validateOptionsResult.ErrorMessage);
-    }
-
-    [TestMethod]
-    public async Task IsInvalid_When_Server_DotnetTestCli_With_WebSocketTransport_Missing_Token()
-    {
-        var provider = new PlatformCommandLineProvider();
-        var options = new Dictionary<string, string[]>
-        {
-            { PlatformCommandLineProvider.ServerOptionKey, ["dotnettestcli"] },
-            { PlatformCommandLineProvider.DotNetTestTransportOptionKey, ["websocket"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey, ["ws://127.0.0.1:5000/dotnettest"] },
-        };
-
-        ValidationResult validateOptionsResult = await provider.ValidateCommandLineOptionsAsync(new TestCommandLineOptions(options)).ConfigureAwait(false);
-        Assert.IsFalse(validateOptionsResult.IsValid);
-        Assert.AreEqual(PlatformResources.PlatformCommandLineDotnetTestWebSocketRequiresEndpointAndToken, validateOptionsResult.ErrorMessage);
-    }
-
-    [TestMethod]
-    public async Task IsInvalid_When_Server_DotnetTestCli_With_Pipe_And_WebSocketTransport_Together()
-    {
-        var provider = new PlatformCommandLineProvider();
-        var options = new Dictionary<string, string[]>
-        {
-            { PlatformCommandLineProvider.ServerOptionKey, ["dotnettestcli"] },
-            { PlatformCommandLineProvider.DotNetTestPipeOptionKey, ["pipe-name"] },
-            { PlatformCommandLineProvider.DotNetTestTransportOptionKey, ["websocket"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey, ["ws://127.0.0.1:5000/dotnettest"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketTokenOptionKey, ["some-token"] },
-        };
-
-        ValidationResult validateOptionsResult = await provider.ValidateCommandLineOptionsAsync(new TestCommandLineOptions(options)).ConfigureAwait(false);
-        Assert.IsFalse(validateOptionsResult.IsValid);
-        Assert.AreEqual(PlatformResources.PlatformCommandLineDotnetTestTransportConflict, validateOptionsResult.ErrorMessage);
-    }
-
-    [TestMethod]
-    public async Task IsInvalid_When_Server_DotnetTestCli_With_Pipe_And_WebSocketEndpoint_Together()
-    {
-        var provider = new PlatformCommandLineProvider();
-        var options = new Dictionary<string, string[]>
-        {
-            { PlatformCommandLineProvider.ServerOptionKey, ["dotnettestcli"] },
-            { PlatformCommandLineProvider.DotNetTestPipeOptionKey, ["pipe-name"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey, ["ws://127.0.0.1:5000/dotnettest"] },
-        };
-
-        ValidationResult validateOptionsResult = await provider.ValidateCommandLineOptionsAsync(new TestCommandLineOptions(options)).ConfigureAwait(false);
-        Assert.IsFalse(validateOptionsResult.IsValid);
-        Assert.AreEqual(PlatformResources.PlatformCommandLineDotnetTestTransportConflict, validateOptionsResult.ErrorMessage);
-    }
-
-    [TestMethod]
-    public async Task IsInvalid_When_Server_DotnetTestCli_With_WebSocketOptions_But_Transport_Pipe()
-    {
-        var provider = new PlatformCommandLineProvider();
-        var options = new Dictionary<string, string[]>
-        {
-            { PlatformCommandLineProvider.ServerOptionKey, ["dotnettestcli"] },
-            { PlatformCommandLineProvider.DotNetTestTransportOptionKey, ["pipe"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketEndpointOptionKey, ["ws://127.0.0.1:5000/dotnettest"] },
-            { PlatformCommandLineProvider.DotNetTestWebSocketTokenOptionKey, ["some-token"] },
-        };
-
-        ValidationResult validateOptionsResult = await provider.ValidateCommandLineOptionsAsync(new TestCommandLineOptions(options)).ConfigureAwait(false);
-        Assert.IsFalse(validateOptionsResult.IsValid);
-        Assert.AreEqual(PlatformResources.PlatformCommandLineDotnetTestWebSocketOptionsRequireTransport, validateOptionsResult.ErrorMessage);
-    }
-
     [TestMethod]
     public void IsListTestsJsonOutput_ReturnsTrueOnlyWhenJsonArgumentSet()
     {
diff --git a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/IPC/DotnetTestWebSocketClientTests.cs b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/IPC/DotnetTestWebSocketClientTests.cs
deleted file mode 100644
index dbd30c79a1..0000000000
--- a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/IPC/DotnetTestWebSocketClientTests.cs
+++ /dev/null
@@ -1,473 +0,0 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-#if NET
-using System.Net;
-using System.Net.Sockets;
-using System.Net.WebSockets;
-using System.Security.Cryptography;
-using System.Text;
-#endif
-
-using Microsoft.Testing.Platform.Helpers;
-using Microsoft.Testing.Platform.IPC;
-using Microsoft.Testing.Platform.IPC.Models;
-using Microsoft.Testing.Platform.IPC.Serializers;
-
-using Moq;
-
-namespace Microsoft.Testing.Platform.UnitTests;
-
-/// <summary>
-/// Tests for the WebSocket transport of the 'dotnet test' pipe protocol (<see cref="DotnetTestWebSocketClient"/>,
-/// <see cref="ClientWebSocketDuplexStream"/>). These tests focus on the transport bootstrap itself -
-/// authentication, connect, and request/reply framing over a real loopback WebSocket - since the wire protocol
-/// carried over the connection is exactly the one the named-pipe transport already uses (see
-/// <see cref="IPCTests"/>/<see cref="ProtocolTests"/>).
-/// </summary>
-[TestClass]
-[UnsupportedOSPlatform("browser")]
-public sealed class DotnetTestWebSocketClientTests
-{
-    [TestMethod]
-    public void BuildAuthenticatedUri_AppendsTokenAsQueryParameter_WhenNoExistingQuery()
-    {
-        Uri result = DotnetTestWebSocketClient.BuildAuthenticatedUri(new Uri("ws://127.0.0.1:5000/dotnettest"), "abc123");
-
-        Assert.AreEqual("ws://127.0.0.1:5000/dotnettest?dotnetTestToken=abc123", result.AbsoluteUri);
-    }
-
-    [TestMethod]
-    public void BuildAuthenticatedUri_AppendsTokenWithAmpersand_WhenQueryAlreadyPresent()
-    {
-        Uri result = DotnetTestWebSocketClient.BuildAuthenticatedUri(new Uri("ws://127.0.0.1:5000/dotnettest?foo=bar"), "abc123");
-
-        Assert.AreEqual("ws://127.0.0.1:5000/dotnettest?foo=bar&dotnetTestToken=abc123", result.AbsoluteUri);
-    }
-
-    [TestMethod]
-    public void BuildAuthenticatedUri_EscapesSpecialCharactersInToken()
-    {
-        Uri result = DotnetTestWebSocketClient.BuildAuthenticatedUri(new Uri("ws://127.0.0.1:5000/dotnettest"), "a b&c=d");
-
-        Assert.AreEqual("ws://127.0.0.1:5000/dotnettest?dotnetTestToken=a%20b%26c%3Dd", result.AbsoluteUri);
-    }
-
-    [TestMethod]
-    public void BuildAuthenticatedUri_InsertsTokenBeforeFragment()
-    {
-        Uri result = DotnetTestWebSocketClient.BuildAuthenticatedUri(new Uri("ws://127.0.0.1:5000/dotnettest#frag"), "abc123");
-
-        Assert.AreEqual("ws://127.0.0.1:5000/dotnettest?dotnetTestToken=abc123#frag", result.AbsoluteUri);
-    }
-
-#if NET
-    [TestMethod]
-    public async Task ClientWebSocketDuplexStream_ReadAsync_WithZeroCount_ReturnsImmediatelyWithoutReceiving()
-    {
-        var webSocket = new Mock<WebSocket>();
-        using ClientWebSocketDuplexStream stream = new(webSocket.Object);
-
-        int result = await stream.ReadAsync([], 0, 0, CancellationToken.None);
-
-        Assert.AreEqual(0, result);
-        webSocket.Verify(
-            socket => socket.ReceiveAsync(It.IsAny<ArraySegment<byte>>(), It.IsAny<CancellationToken>()),
-            Times.Never);
-    }
-
-    [TestMethod]
-    [Timeout(30_000, CooperativeCancellation = true)]
-    public async Task ConnectAsync_RequestReplyAsync_RoundTripsRealFramingOverLoopbackWebSocket()
-    {
-        using CancellationTokenSource cts = new(TimeSpan.FromSeconds(25));
-        TcpListener listener = new(IPAddress.Loopback, 0);
-        listener.Start();
-        try
-        {
-            int port = ((IPEndPoint)listener.LocalEndpoint).Port;
-
-            Task<(HandshakeMessage Received, string RequestLine)> serverTask = AcceptReadAndReplyAsync(listener, new Dictionary<byte, string> { [9] = "negotiated-value" }, cts.Token);
-
-            IEnvironment environment = new Mock<IEnvironment>().Object;
-            DotnetTestWebSocketClient client = new(new Uri($"ws://127.0.0.1:{port}/dotnettest"), "s3cr3t-token", environment, exitProcessOnConnectionLoss: false);
-            RegisterSerializerViaReflection(client, new HandshakeMessageSerializer(), typeof(HandshakeMessage));
-
-            try
-            {
-                await client.ConnectAsync(cts.Token);
-                Assert.IsTrue(client.IsConnected);
-
-                HandshakeMessage sent = new(new Dictionary<byte, string> { [0] = "1234", [5] = "TestHost" });
-                HandshakeMessage response = await client.RequestReplyAsync<HandshakeMessage, HandshakeMessage>(sent, cts.Token);
-                Assert.IsNotNull(response.Properties);
-                Assert.AreEqual("negotiated-value", response.Properties![9]);
-
-                (HandshakeMessage received, string requestLine) = await serverTask;
-                Assert.AreEqual("1234", received.Properties?[0]);
-                Assert.AreEqual("TestHost", received.Properties?[5]);
-
-                // The token must have travelled as a query-string parameter (browsers cannot set custom
-                // headers on the WebSocket upgrade handshake) - see DotnetTestWebSocketClient.BuildAuthenticatedUri.
-                Assert.Contains("dotnetTestToken=s3cr3t-token", requestLine);
-            }
-            finally
-            {
-                client.Dispose();
-            }
-        }
-        finally
-        {
-            listener.Stop();
-        }
-    }
-
-    [TestMethod]
-    [Timeout(30_000, CooperativeCancellation = true)]
-    public async Task ConnectAsync_RequestReplyAsync_RoundTripsLargeMessageSpanningMultipleWebSocketReceives()
-    {
-        // ClientWebSocketDuplexStream's internal receive buffer is 8192 bytes. A property value comfortably
-        // larger than that forces NamedPipeConnectionBase.ReadNextMessageAsync to pull the frame across several
-        // WebSocket receives instead of a single one, exercising the offset/count buffering carried across
-        // ReadAsync calls (_receiveOffset/_receiveCount) that the single-frame round-trip test above never
-        // needs to touch.
-        string largeValue = new('x', 50_000);
-
-        using CancellationTokenSource cts = new(TimeSpan.FromSeconds(25));
-        TcpListener listener = new(IPAddress.Loopback, 0);
-        listener.Start();
-        try
-        {
-            int port = ((IPEndPoint)listener.LocalEndpoint).Port;
-
-            Task<(HandshakeMessage Received, string RequestLine)> serverTask = AcceptReadAndReplyAsync(listener, new Dictionary<byte, string> { [9] = "ok" }, cts.Token);
-
-            IEnvironment environment = new Mock<IEnvironment>().Object;
-            DotnetTestWebSocketClient client = new(new Uri($"ws://127.0.0.1:{port}/dotnettest"), "s3cr3t-token", environment, exitProcessOnConnectionLoss: false);
-            RegisterSerializerViaReflection(client, new HandshakeMessageSerializer(), typeof(HandshakeMessage));
-
-            try
-            {
-                await client.ConnectAsync(cts.Token);
-
-                HandshakeMessage sent = new(new Dictionary<byte, string> { [0] = largeValue });
-                HandshakeMessage response = await client.RequestReplyAsync<HandshakeMessage, HandshakeMessage>(sent, cts.Token);
-                Assert.AreEqual("ok", response.Properties?[9]);
-
-                (HandshakeMessage received, _) = await serverTask;
-                Assert.AreEqual(largeValue, received.Properties?[0]);
-            }
-            finally
-            {
-                client.Dispose();
-            }
-        }
-        finally
-        {
-            listener.Stop();
-        }
-    }
-
-    [TestMethod]
-    [Timeout(30_000, CooperativeCancellation = true)]
-    public async Task RequestReplyAsync_WhenServerClosesWithoutResponding_ThrowsIOException_WhenExitProcessOnConnectionLossIsFalse()
-    {
-        using CancellationTokenSource cts = new(TimeSpan.FromSeconds(25));
-        TcpListener listener = new(IPAddress.Loopback, 0);
-        listener.Start();
-        try
-        {
-            int port = ((IPEndPoint)listener.LocalEndpoint).Port;
-
-            Task serverTask = AcceptReadAndDisconnectWithoutRespondingAsync(listener, cts.Token);
-
-            IEnvironment environment = new Mock<IEnvironment>().Object;
-
-            // exitProcessOnConnectionLoss: false mirrors how DotnetTestConnection opens auxiliary channels: a
-            // dropped connection must surface as an exception the caller can handle, not kill the process. This
-            // is the WebSocket-transport counterpart of NamedPipeClient's identical behavior for exitProcessOnConnectionLoss: false.
-            DotnetTestWebSocketClient client = new(new Uri($"ws://127.0.0.1:{port}/dotnettest"), "s3cr3t-token", environment, exitProcessOnConnectionLoss: false);
-            RegisterSerializerViaReflection(client, new HandshakeMessageSerializer(), typeof(HandshakeMessage));
-
-            try
-            {
-                await client.ConnectAsync(cts.Token);
-
-                HandshakeMessage sent = new(new Dictionary<byte, string> { [0] = "1234" });
-                await Assert.ThrowsExactlyAsync<IOException>(() => client.RequestReplyAsync<HandshakeMessage, HandshakeMessage>(sent, cts.Token));
-
-                // IEnvironment.Exit must never have been called: with exitProcessOnConnectionLoss: false a
-                // connection loss is the caller's problem to handle, not a reason to terminate the process.
-                Mock.Get(environment).Verify(e => e.Exit(It.IsAny<int>()), Times.Never);
-
-                await serverTask;
-            }
-            finally
-            {
-                client.Dispose();
-            }
-        }
-        finally
-        {
-            listener.Stop();
-        }
-    }
-
-    [TestMethod]
-    [Timeout(30_000, CooperativeCancellation = true)]
-    public async Task RequestReplyAsync_WhenCancelled_ThrowsOperationCanceledExceptionAndDoesNotHang()
-    {
-        using CancellationTokenSource testCts = new(TimeSpan.FromSeconds(25));
-        TcpListener listener = new(IPAddress.Loopback, 0);
-        listener.Start();
-        try
-        {
-            int port = ((IPEndPoint)listener.LocalEndpoint).Port;
-
-            // The server accepts the connection and completes the WebSocket handshake, but then deliberately
-            // never reads the request or sends a reply - holding the connection open so RequestReplyAsync would
-            // otherwise wait forever. This isolates cancellation of the read from a peer disconnect (already
-            // covered by the test above): the connection stays healthy, only the caller's token fires.
-            Task<TcpClient> serverAcceptTask = AcceptAndCompleteHandshakeOnlyAsync(listener, testCts.Token);
-
-            IEnvironment environment = new Mock<IEnvironment>().Object;
-            DotnetTestWebSocketClient client = new(new Uri($"ws://127.0.0.1:{port}/dotnettest"), "s3cr3t-token", environment, exitProcessOnConnectionLoss: false);
-            RegisterSerializerViaReflection(client, new HandshakeMessageSerializer(), typeof(HandshakeMessage));
-
-            try
-            {
-                await client.ConnectAsync(testCts.Token);
-
-                using CancellationTokenSource requestCts = new(TimeSpan.FromMilliseconds(200));
-                HandshakeMessage sent = new(new Dictionary<byte, string> { [0] = "1234" });
-
-                // Not ThrowsExactlyAsync: cancelling a pending Stream read/write typically surfaces as
-                // TaskCanceledException (a subclass of OperationCanceledException), not the base type itself -
-                // same convention used elsewhere in this test project (e.g. TaskExtensionsTests).
-                await Assert.ThrowsAsync<OperationCanceledException>(() => client.RequestReplyAsync<HandshakeMessage, HandshakeMessage>(sent, requestCts.Token));
-            }
-            finally
-            {
-                client.Dispose();
-                using TcpClient serverClient = await serverAcceptTask;
-            }
-        }
-        finally
-        {
-            listener.Stop();
-        }
-    }
-
-    [TestMethod]
-    [Timeout(30_000, CooperativeCancellation = true)]
-    public async Task ReadAsync_WhenServerSendsEmptyBinaryMessageBeforeReply_IgnoresItInsteadOfTreatingAsEof()
-    {
-        // Regression test for a real bug found and fixed in ClientWebSocketDuplexStream.ReadAsync: a zero-length,
-        // non-Close binary WebSocket message (a legitimate occurrence - e.g. an empty keep-alive, or here, a
-        // deliberately injected empty frame) was briefly misreported as end-of-stream/peer-disconnected, because
-        // the retry loop only re-read for a non-final *fragment*, not for a complete zero-byte message. If that
-        // bug were reintroduced, this test would fail: RequestReplyAsync would observe an EOF where the server's
-        // real reply should be and throw IOException (via HandleMissingResponseAsync) instead of returning it.
-        using CancellationTokenSource cts = new(TimeSpan.FromSeconds(25));
-        TcpListener listener = new(IPAddress.Loopback, 0);
-        listener.Start();
-        try
-        {
-            int port = ((IPEndPoint)listener.LocalEndpoint).Port;
-
-            Task serverTask = AcceptReadSendEmptyMessageThenReplyAsync(listener, new Dictionary<byte, string> { [9] = "ok" }, cts.Token);
-
-            IEnvironment environment = new Mock<IEnvironment>().Object;
-            DotnetTestWebSocketClient client = new(new Uri($"ws://127.0.0.1:{port}/dotnettest"), "s3cr3t-token", environment, exitProcessOnConnectionLoss: false);
-            RegisterSerializerViaReflection(client, new HandshakeMessageSerializer(), typeof(HandshakeMessage));
-
-            try
-            {
-                await client.ConnectAsync(cts.Token);
-
-                HandshakeMessage sent = new(new Dictionary<byte, string> { [0] = "1234" });
-                HandshakeMessage response = await client.RequestReplyAsync<HandshakeMessage, HandshakeMessage>(sent, cts.Token);
-                Assert.AreEqual("ok", response.Properties?[9]);
-
-                await serverTask;
-            }
-            finally
-            {
-                client.Dispose();
-            }
-        }
-        finally
-        {
-            listener.Stop();
-        }
-    }
-
-    private static Task<(HandshakeMessage Result, string RequestLine)> AcceptReadAndReplyAsync(TcpListener listener, Dictionary<byte, string> replyProperties, CancellationToken cancellationToken)
-        => AcceptAndHandleAsync(
-            listener,
-            async (stream, requestPayload, cancellationToken) =>
-            {
-                int serializerId = BitConverter.ToInt32(requestPayload, 0);
-                Assert.AreEqual(HandshakeMessageFieldsId.MessagesSerializerId, serializerId);
-
-                using MemoryStream requestBody = new(requestPayload, 4, requestPayload.Length - 4);
-                HandshakeMessageSerializer serializer = new();
-                var received = (HandshakeMessage)ProtocolSerializerTestHelper.Deserialize(serializer, requestBody);
-
-                HandshakeMessage reply = new(replyProperties);
-                using MemoryStream replyBody = new();
-                ProtocolSerializerTestHelper.Serialize(serializer, reply, replyBody);
-                await WriteFrameAsync(stream, HandshakeMessageFieldsId.MessagesSerializerId, replyBody.ToArray(), cancellationToken);
-
-                return received;
-            },
-            cancellationToken);
-
-    private static Task AcceptReadAndDisconnectWithoutRespondingAsync(TcpListener listener, CancellationToken cancellationToken)
-        => AcceptAndHandleAsync<object?>(
-            listener,
-            (_, _, _) => Task.FromResult<object?>(null),
-            cancellationToken);
-
-    private static Task AcceptReadSendEmptyMessageThenReplyAsync(TcpListener listener, Dictionary<byte, string> replyProperties, CancellationToken cancellationToken)
-        => AcceptAndHandleAsync<object?>(
-            listener,
-            async (stream, requestPayload, cancellationToken) =>
-            {
-                using MemoryStream requestBody = new(requestPayload, 4, requestPayload.Length - 4);
-                HandshakeMessageSerializer serializer = new();
-                ProtocolSerializerTestHelper.Deserialize(serializer, requestBody);
-
-                // Send a genuine zero-length, non-Close binary WebSocket message before the real reply. Writing
-                // a 0-byte buffer through the Stream still issues one WebSocket.SendAsync(..., endOfMessage:
-                // true, ...) call underneath (see ClientWebSocketDuplexStream.WriteAsync), producing exactly the
-                // scenario the regression test above guards against: a conforming reader must skip this and
-                // keep reading rather than reporting a false EOF.
-                await stream.WriteAsync([], 0, 0, cancellationToken);
-
-                HandshakeMessage reply = new(replyProperties);
-                using MemoryStream replyBody = new();
-                ProtocolSerializerTestHelper.Serialize(serializer, reply, replyBody);
-                await WriteFrameAsync(stream, HandshakeMessageFieldsId.MessagesSerializerId, replyBody.ToArray(), cancellationToken);
-
-                return null;
-            },
-            cancellationToken);
-
-    // Shared plumbing for the server-side half of a loopback test: accepts one connection, completes the RFC
-    // 6455 handshake, reads exactly one request frame, hands it to <paramref name="handleRequestAsync"/> (which
-    // may reply, or not, or reply with an extra empty message first - see the callers above), then closes the
-    // connection. Factored out so each scenario only needs to express what differs about the server's reaction
-    // to the request.
-    private static async Task<(T Result, string RequestLine)> AcceptAndHandleAsync<T>(TcpListener listener, Func<Stream, byte[], CancellationToken, Task<T>> handleRequestAsync, CancellationToken cancellationToken)
-    {
-        using TcpClient tcpClient = await listener.AcceptTcpClientAsync(cancellationToken);
-        NetworkStream networkStream = tcpClient.GetStream();
-
-        string requestLine = await CompleteServerHandshakeAsync(networkStream, cancellationToken);
-
-        using var serverSocket = WebSocket.CreateFromStream(networkStream, isServer: true, subProtocol: null, keepAliveInterval: Timeout.InfiniteTimeSpan);
-        ClientWebSocketDuplexStream stream = new(serverSocket);
-
-        byte[] requestPayload = await ReadFrameAsync(stream, cancellationToken);
-        T result = await handleRequestAsync(stream, requestPayload, cancellationToken);
-        return (result, requestLine);
-    }
-
-    private static async Task<TcpClient> AcceptAndCompleteHandshakeOnlyAsync(TcpListener listener, CancellationToken cancellationToken)
-    {
-        TcpClient tcpClient = await listener.AcceptTcpClientAsync(cancellationToken);
-        await CompleteServerHandshakeAsync(tcpClient.GetStream(), cancellationToken);
-        return tcpClient;
-    }
-
-    // Minimal RFC 6455 server-side opening handshake: read the HTTP request line + headers (up to the blank
-    // line terminator), extract Sec-WebSocket-Key, and reply with the computed Sec-WebSocket-Accept. Everything
-    // after this point is real WebSocket framing, handled by WebSocket.CreateFromStream.
-    private static async Task<string> CompleteServerHandshakeAsync(NetworkStream networkStream, CancellationToken cancellationToken)
-    {
-        List<byte> buffer = [];
-        byte[] singleByte = new byte[1];
-        while (true)
-        {
-            int read = await networkStream.ReadAsync(singleByte, cancellationToken);
-            if (read == 0)
-            {
-                throw new IOException("Connection closed before the WebSocket handshake completed.");
-            }
-
-            buffer.Add(singleByte[0]);
-            if (buffer.Count >= 4 &&
-                buffer[^4] == (byte)'\r' && buffer[^3] == (byte)'\n' &&
-                buffer[^2] == (byte)'\r' && buffer[^1] == (byte)'\n')
-            {
-                break;
-            }
-        }
-
-        string requestText = Encoding.ASCII.GetString([.. buffer]);
-        string key = requestText
-            .Split("\r\n")
-            .Single(line => line.StartsWith("Sec-WebSocket-Key:", StringComparison.OrdinalIgnoreCase))
-            .Split(':', 2)[1]
-            .Trim();
-
-        string accept = Convert.ToBase64String(SHA1.HashData(Encoding.ASCII.GetBytes(key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11")));
-        string response = $"HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: {accept}\r\n\r\n";
-        await networkStream.WriteAsync(Encoding.ASCII.GetBytes(response), cancellationToken);
-        return requestText;
-    }
-
-    // Mirrors the documented wire format (§4 of docs/mstest-runner-protocol/004-protocol-dotnet-test-pipe.md):
-    // int32 payloadLength (= 4 + body.Length), int32 serializerId, then the body. Deliberately independent of
-    // NamedPipeConnectionBase so this test does not depend on which of its (possibly duplicated, see this
-    // project's local IPC/*.cs source links) copies is in scope.
-    private static async Task<byte[]> ReadFrameAsync(Stream stream, CancellationToken cancellationToken)
-    {
-        byte[] header = new byte[4];
-        await ReadExactAsync(stream, header, cancellationToken);
-        int payloadLength = BitConverter.ToInt32(header, 0);
-        byte[] payload = new byte[payloadLength];
-        await ReadExactAsync(stream, payload, cancellationToken);
-        return payload;
-    }
-
-    private static async Task ReadExactAsync(Stream stream, byte[] buffer, CancellationToken cancellationToken)
-    {
-        int offset = 0;
-        while (offset < buffer.Length)
-        {
-            int read = await stream.ReadAsync(buffer.AsMemory(offset), cancellationToken);
-            if (read == 0)
-            {
-                throw new IOException("Unexpected end of stream while reading a frame.");
-            }
-
-            offset += read;
-        }
-    }
-
-    private static async Task WriteFrameAsync(Stream stream, int serializerId, byte[] body, CancellationToken cancellationToken)
-    {
-        int payloadLength = 4 + body.Length;
-        byte[] frame = new byte[4 + payloadLength];
-        BitConverter.GetBytes(payloadLength).CopyTo(frame, 0);
-        BitConverter.GetBytes(serializerId).CopyTo(frame, 4);
-        body.CopyTo(frame, 8);
-        await stream.WriteAsync(frame, cancellationToken);
-    }
-
-    // NamedPipeBase.RegisterSerializer is public but inherited from a base class that is also (separately)
-    // compiled directly into this test project from linked source (see this project's IPC/*.cs Compile Include
-    // items). That makes ordinary strongly-typed member lookup on the assembly-referenced DotnetTestWebSocketClient
-    // ambiguous with the test project's own same-named local copy, so - exactly like ProtocolSerializerTestHelper
-    // does for the serializer Serialize/Deserialize methods - this reaches the real inherited method via
-    // reflection instead, which resolves purely at runtime against the actual (unambiguous) object instance.
-    private static void RegisterSerializerViaReflection(object client, object serializer, Type messageType)
-    {
-        MethodInfo method = client.GetType().GetMethod("RegisterSerializer", BindingFlags.Public | BindingFlags.Instance)
-            ?? throw new InvalidOperationException("RegisterSerializer method not found via reflection.");
-        method.Invoke(client, [serializer, messageType]);
-    }
-#endif
-}
diff --git a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/IPC/ProtocolTests.cs b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/IPC/ProtocolTests.cs
index 5b64add809..cf2a78ecc7 100644
--- a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/IPC/ProtocolTests.cs
+++ b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/IPC/ProtocolTests.cs
@@ -310,7 +310,6 @@ public void HandshakeMessagePropertyNames_ValuesAreStable()
             { HandshakeMessagePropertyNames.AttemptNumber, nameof(HandshakeMessagePropertyNames.AttemptNumber) },
             { HandshakeMessagePropertyNames.SupportedPostProcessorKinds, nameof(HandshakeMessagePropertyNames.SupportedPostProcessorKinds) },
             { HandshakeMessagePropertyNames.SupportedPostProcessorExtensionsLegacy, nameof(HandshakeMessagePropertyNames.SupportedPostProcessorExtensionsLegacy) },
-            { HandshakeMessagePropertyNames.Transport, nameof(HandshakeMessagePropertyNames.Transport) },
         };
 
         Assert.AreEqual(nameof(HandshakeMessagePropertyNames.PID), properties[0]);
@@ -329,7 +328,6 @@ public void HandshakeMessagePropertyNames_ValuesAreStable()
         Assert.AreEqual(nameof(HandshakeMessagePropertyNames.AttemptNumber), properties[13]);
         Assert.AreEqual(nameof(HandshakeMessagePropertyNames.SupportedPostProcessorKinds), properties[14]);
         Assert.AreEqual(nameof(HandshakeMessagePropertyNames.SupportedPostProcessorExtensionsLegacy), properties[15]);
-        Assert.AreEqual(nameof(HandshakeMessagePropertyNames.Transport), properties[16]);
     }
 
     // The HandshakeMessageExecutionModes string values flow over IPC to
@@ -579,6 +577,6 @@ public void ProtocolVersion_IsStable()
         // Indirect through a collection so the MSTest analyzer does not flag the comparison of a compile-time
         // constant as "always true" (MSTEST0032).
         string[] versions = [ProtocolConstants.SupportedVersions];
-        Assert.AreEqual("1.0.0;1.1.0;1.2.0;1.3.0;1.4.0;1.5.0", versions[0]);
+        Assert.AreEqual("1.0.0;1.1.0;1.2.0;1.3.0;1.4.0", versions[0]);
     }
 }
diff --git a/test/Utilities/Microsoft.Testing.TestInfrastructure/WasmRuntime.cs b/test/Utilities/Microsoft.Testing.TestInfrastructure/WasmRuntime.cs
index 849fa2c64a..081c454267 100644
--- a/test/Utilities/Microsoft.Testing.TestInfrastructure/WasmRuntime.cs
+++ b/test/Utilities/Microsoft.Testing.TestInfrastructure/WasmRuntime.cs
@@ -238,13 +238,13 @@ public static string GetBrowserAppBundlePath(string targetAssetPath, string targ
     /// than calling <c>process.exit()</c> so Node drains redirected streams before exiting.
     /// </summary>
     public static async Task<(int ExitCode, string Output, string Error, string Combined)> RunUnderNodeAsync(
-        string node, string appBundle, string nodeRunnerSource, CancellationToken cancellationToken, bool enableWebSocket = false)
+        string node, string appBundle, string nodeRunnerSource, CancellationToken cancellationToken)
     {
         File.WriteAllText(Path.Combine(appBundle, "runtests.mjs"), nodeRunnerSource);
 
         var commandLine = new CommandLine();
         int exitCode = await commandLine.RunAsyncAndReturnExitCodeAsync(
-            $"\"{node}\"{(enableWebSocket ? " --experimental-websocket" : string.Empty)} runtests.mjs",
+            $"\"{node}\" runtests.mjs",
             workingDirectory: appBundle,
             cancellationToken: cancellationToken);