fix: migration to httpx2

.github/actions/spelling/allow.txt

@@ -1,4 +1,4 @@
 a2a
 A2A
 A2AFastAPI
 AAgent
@@ -29,7 +29,7 @@
 AUser
 autouse
 backticks
 base64url
 buf
 bufbuild
 cla
@@ -49,7 +49,7 @@
 dsn
 DSNs
 dunders
 ES256
 euo
 EUR
 evt
@@ -66,8 +66,8 @@
 gowebpki
 GVsb
 hazmat
 HS256
 HS384
 ietf
 importlib
 initdb
@@ -110,11 +110,11 @@
 Oneof
 OpenAPI
 openapiv
 openapiv2
 opensource
 otherurl
 outerjoin
 pb2
 podman
 Podman
 poolclass
@@ -135,10 +135,9 @@
 pyupgrade
 pyversions
 redef
-respx
 resub
 rmi
 RS256
 RUF
 Rundgren
 SECP

.gitignore

@@ -13,6 +13,7 @@ spec.json
 docker-compose.yaml
 .geminiignore
 docs/ai/ai_learnings.md
+.idea
 
 # ITK Integration Test Artifacts
 itk/a2a-itk/

itk/acts_client_parse.py

@@ -33,7 +33,7 @@
 
 from typing import Any
 
-import httpx
+import httpx2
 
 from google.protobuf.json_format import MessageToDict
 
@@ -70,7 +70,7 @@ def _is_enveloped(payload: Any) -> bool:
     )
 
 
-def _transport(payload: Any) -> httpx.MockTransport:
+def _transport(payload: Any) -> httpx2.MockTransport:
     """An HTTP transport that answers every request with ``payload``.
 
     The response's JSON-RPC ``id`` is rewritten to echo the request's, which
@@ -82,7 +82,7 @@ def _transport(payload: Any) -> httpx.MockTransport:
     express.
     """
 
-    def handler(request: httpx.Request) -> httpx.Response:
+    def handler(request: httpx2.Request) -> httpx2.Response:
         body = payload
         if _is_enveloped(payload):
             try:
@@ -91,9 +91,9 @@ def handler(request: httpx.Request) -> httpx.Response:
                 sent = None
             if isinstance(sent, dict) and 'id' in sent:
                 body = {**payload, 'id': sent['id']}
-        return httpx.Response(200, json=body)
+        return httpx2.Response(200, json=body)
 
-    return httpx.MockTransport(handler)
+    return httpx2.MockTransport(handler)
 
 
 def _scaffold_card() -> AgentCard:
@@ -129,7 +129,7 @@ async def _client(payload: Any) -> Any:
     config = ClientConfig()
     config.streaming = False
     config.supported_protocol_bindings = [TransportProtocol.JSONRPC]
-    config.httpx_client = httpx.AsyncClient(transport=_transport(payload))
+    config.httpx_client = httpx2.AsyncClient(transport=_transport(payload))
     return await create_client(_scaffold_card(), client_config=config)
 
 
@@ -141,15 +141,15 @@ async def _parse_card(payload: Any, path: str) -> dict[str, Any]:
     plain HTTP on every binding, so there is no envelope to unwrap. The two
     differ only in the path they are served from.
     """
-    async with httpx.AsyncClient(transport=_transport(payload)) as http:
+    async with httpx2.AsyncClient(transport=_transport(payload)) as http:
         resolver = A2ACardResolver(httpx_client=http, base_url=_BASE_URL)
         card = await resolver.get_agent_card(relative_card_path=path)
         return MessageToDict(card)
 
 
 async def _parse_extended_card_envelope(payload: Any) -> dict[str, Any]:
     """The enveloped form of `get_extended_agent_card`, via the RPC client."""
-    async with httpx.AsyncClient(transport=_transport(payload)) as http:
+    async with httpx2.AsyncClient(transport=_transport(payload)) as http:
         config = ClientConfig()
         config.streaming = False
         config.supported_protocol_bindings = [TransportProtocol.JSONRPC]

itk/main.py

@@ -7,7 +7,7 @@
 import uuid
 
 import grpc
-import httpx
+import httpx2
 import uvicorn
 
 from fastapi import FastAPI
@@ -300,7 +300,7 @@ async def handle_call_agent(
             token='itk-token',  # noqa: S106
         )
 
-    async with httpx.AsyncClient(timeout=30.0) as httpx_client:
+    async with httpx2.AsyncClient(timeout=30.0) as httpx_client:
         config.httpx_client = httpx_client
         try:
             client = await create_client(
@@ -738,7 +738,7 @@ async def main_async(http_port: int, grpc_port: int) -> None:
 
     task_store = InMemoryTaskStore()
     push_config_store = InMemoryPushNotificationConfigStore()
-    httpx_client = httpx.AsyncClient()
+    httpx_client = httpx2.AsyncClient()
     push_sender = BasePushNotificationSender(
         httpx_client=httpx_client,
         config_store=push_config_store,

itk/pyproject.toml

@@ -10,7 +10,6 @@ dependencies = [
     "grpcio-tools",
     "protobuf",
     "sse-starlette",
-    "httpx-sse",
     "packaging",
 ]
 

pyproject.toml

@@ -8,7 +8,7 @@ authors = [{ name = "Google LLC", email = "googleapis-packages@google.com" }]
 requires-python = ">=3.10"
 keywords = ["A2A", "A2A SDK", "A2A Protocol", "Agent2Agent", "Agent 2 Agent"]
 dependencies = [
-  "httpx>=0.28.1",
+  "httpx2>=2.14.0",
   "pydantic>=2.11.3",
   "protobuf>=5.29.5",
   "google-api-core>=1.26.0",
@@ -113,7 +113,6 @@ dev = [
   "pytest-cov>=6.1.1",
   "pytest-mock>=3.14.0",
   "pytest-xdist>=3.6.1",
-  "respx>=0.20.2",
   # Test-only oracle. The RFC 8785 conformance tests check the canonicalizer
   # against an independent implementation, so a mistake shared between the
   # implementation and its tests still shows up. Not a runtime dependency.

samples/agent_card_signing.py

@@ -52,7 +52,7 @@
 from collections.abc import Callable, Mapping
 from typing import Any
 
-import httpx
+import httpx2
 import uvicorn
 
 from cryptography.hazmat.primitives.asymmetric import ec
@@ -275,7 +275,7 @@ def __init__(self, jwks_by_url: Mapping[str, PyJWKSet]) -> None:
 
     @classmethod
     async def fetch(
-        cls, trusted_jku_urls: set[str], http_client: httpx.AsyncClient
+        cls, trusted_jku_urls: set[str], http_client: httpx2.AsyncClient
     ) -> 'JwksKeyProvider':
         """Fetches every trusted JWKS and builds a provider from them.
 
@@ -324,7 +324,7 @@ def __call__(self, kid: str | None, jku: str | None) -> PyJWK:
 
 
 async def create_card_verifier(
-    trusted_jku_urls: set[str], http_client: httpx.AsyncClient
+    trusted_jku_urls: set[str], http_client: httpx2.AsyncClient
 ) -> Callable[[AgentCard], None]:
     """Builds a verifier that accepts cards signed by the trusted keys.
 
@@ -356,7 +356,7 @@ async def verify_remote_card(base_url: str) -> AgentCard:
         SignatureVerificationError: If the card carries no signature, or none of
             its signatures can be verified.
     """
-    async with httpx.AsyncClient() as http_client:
+    async with httpx2.AsyncClient() as http_client:
         verifier = await create_card_verifier(
             trusted_jku_urls={f'{base_url}{JWKS_WELL_KNOWN_PATH}'},
             http_client=http_client,
@@ -373,7 +373,7 @@ async def verify_remote_card(base_url: str) -> AgentCard:
 
 
 async def _fetch_card_json(
-    base_url: str, http_client: httpx.AsyncClient
+    base_url: str, http_client: httpx2.AsyncClient
 ) -> dict[str, Any]:
     """Fetches the raw Agent Card JSON, bypassing verification."""
     response = await http_client.get(f'{base_url}{AGENT_CARD_WELL_KNOWN_PATH}')
@@ -384,7 +384,7 @@ async def _fetch_card_json(
 
 async def run_demo(base_url: str) -> None:
     """Verifies a good card, then two cards a verifier should reject."""
-    async with httpx.AsyncClient() as http_client:
+    async with httpx2.AsyncClient() as http_client:
         verifier = await create_card_verifier(
             trusted_jku_urls={f'{base_url}{JWKS_WELL_KNOWN_PATH}'},
             http_client=http_client,

samples/cli.py

@@ -7,7 +7,7 @@
 from typing import Any
 
 import grpc
-import httpx
+import httpx2
 
 from a2a.client import A2ACardResolver, ClientConfig, create_client
 from a2a.helpers import get_artifact_text, get_message_text
@@ -83,7 +83,7 @@ async def main() -> None:
         f'Connecting to {args.url} (preferred transport: {args.transport or "Any"})'
     )
 
-    async with httpx.AsyncClient() as httpx_client:
+    async with httpx2.AsyncClient() as httpx_client:
         resolver = A2ACardResolver(httpx_client, args.url)
         card = await resolver.get_agent_card()
         print('\n✓ Agent Card Found:')
@@ -124,7 +124,7 @@ async def main() -> None:
         try:
             stream = client.send_message(request)
             current_task_id = await _handle_stream(stream, current_task_id)
-        except (httpx.RequestError, grpc.RpcError) as e:
+        except (httpx2.RequestError, grpc.RpcError) as e:
             print(f'Error communicating with agent: {e}')
 
     await client.close()

samples/clustermode/exercise.py

@@ -18,7 +18,7 @@
 
 from typing import Any
 
-import httpx
+import httpx2
 
 from google.protobuf.json_format import MessageToDict, ParseDict
 from google.protobuf.message import Message as ProtoMessage
@@ -46,7 +46,7 @@ def _endpoint(host: str, port: int) -> str:
 
 
 async def _rpc(
-    client: httpx.AsyncClient,
+    client: httpx2.AsyncClient,
     url: str,
     method: str,
     params_msg: ProtoMessage,
@@ -69,7 +69,7 @@ async def _rpc(
     return data['result']
 
 
-async def _get_task(client: httpx.AsyncClient, url: str, task_id: str) -> Task:
+async def _get_task(client: httpx2.AsyncClient, url: str, task_id: str) -> Task:
     """Fetches a task via GetTask from the given replica."""
     result = await _rpc(client, url, 'GetTask', GetTaskRequest(id=task_id))
     task = Task()
@@ -78,7 +78,7 @@ async def _get_task(client: httpx.AsyncClient, url: str, task_id: str) -> Task:
 
 
 async def _start_streaming(
-    client: httpx.AsyncClient, url: str, send: SendMessageRequest
+    client: httpx2.AsyncClient, url: str, send: SendMessageRequest
 ) -> tuple[str, asyncio.Task[None]]:
     """Starts a streaming send; returns (task_id, drainer task).
 
@@ -128,7 +128,7 @@ async def run(host: str, ports: list[int]) -> None:
 
     urls = [_endpoint(host, p) for p in ports]
 
-    async with httpx.AsyncClient() as client:
+    async with httpx2.AsyncClient() as client:
         # 1) Start a streaming task on replica 0. The stream stays open (agent
         #    runs) while we observe and cancel from other replicas.
         print(f'[send]      -> replica 0 ({urls[0]}) (streaming)')

src/a2a/client/card_resolver.py

@@ -4,7 +4,7 @@
 from collections.abc import Callable
 from typing import Any
 
-import httpx
+import httpx2
 
 from google.protobuf.json_format import ParseDict, ParseError
 
@@ -133,14 +133,14 @@ class A2ACardResolver:
 
     def __init__(
         self,
-        httpx_client: httpx.AsyncClient,
+        httpx_client: httpx2.AsyncClient,
         base_url: str,
         agent_card_path: str = AGENT_CARD_WELL_KNOWN_PATH,
     ) -> None:
         """Initializes the A2ACardResolver.
 
         Args:
-            httpx_client: An async HTTP client instance (e.g., httpx.AsyncClient).
+            httpx_client: An async HTTP client instance (e.g., httpx2.AsyncClient).
             base_url: The base URL of the agent's host.
             agent_card_path: The path to the agent card endpoint, relative to the base URL.
         """
@@ -164,7 +164,7 @@ async def get_agent_card(
                 relative to the base URL. If None, uses the default public
                 agent card path. Use `'/'` for an empty path.
             http_kwargs: Optional dictionary of keyword arguments to pass to the
-                underlying httpx.get request.
+                underlying httpx2.get request.
             signature_verifier: A callable used to verify the agent card's signatures.
 
         Returns:
@@ -200,7 +200,7 @@ async def get_agent_card(
             agent_card = parse_agent_card(agent_card_data)
             if signature_verifier:
                 signature_verifier(agent_card)
-        except httpx.HTTPStatusError as e:
+        except httpx2.HTTPStatusError as e:
             raise AgentCardResolutionError(
                 f'Failed to fetch agent card from {target_url} (HTTP {e.response.status_code}): {e}',
                 status_code=e.response.status_code,
@@ -209,7 +209,7 @@ async def get_agent_card(
             raise AgentCardResolutionError(
                 f'Failed to parse JSON for agent card from {target_url}: {e}'
             ) from e
-        except httpx.RequestError as e:
+        except httpx2.RequestError as e:
             raise AgentCardResolutionError(
                 f'Network communication error fetching agent card from {target_url}: {e}',
             ) from e

src/a2a/client/client.py

@@ -6,7 +6,7 @@
 from types import TracebackType
 from typing import Any
 
-import httpx
+import httpx2
 
 from pydantic import BaseModel, Field
 from typing_extensions import Self
@@ -48,7 +48,7 @@ class ClientConfig:
     the callers job to check if the response is completed and if not run a
     polling loop."""
 
-    httpx_client: httpx.AsyncClient | None = None
+    httpx_client: httpx2.AsyncClient | None = None
     """Http client to use to connect to agent."""
 
     grpc_channel_factory: Callable[[str], Channel] | None = None

src/a2a/client/client_factory.py

@@ -5,7 +5,7 @@
 from collections.abc import Callable
 from typing import TYPE_CHECKING, Any
 
-import httpx
+import httpx2
 
 from packaging.version import InvalidVersion, Version
 
@@ -38,13 +38,13 @@
 try:
     from a2a.client.transports.grpc import GrpcTransport
 except ImportError:
     GrpcTransport = None  # type: ignore # pyright: ignore
 
 
 try:
     from a2a.compat.v0_3.grpc_transport import CompatGrpcTransport
 except ImportError:
     CompatGrpcTransport = None  # type: ignore # pyright: ignore
 
 logger = logging.getLogger(__name__)
 
@@ -78,7 +78,7 @@
     The client can be used consistently regardless of the transport. This
     aligns the client configuration with the server's capabilities.
 
-    Each created client gets its own `httpx.AsyncClient` and closes it on
+    Each created client gets its own `httpx2.AsyncClient` and closes it on
     `close()`, unless `ClientConfig.httpx_client` is set.
     """
 
@@ -96,11 +96,11 @@
         self._registry: dict[str, TransportProducer] = {}
         self._register_defaults(config.supported_protocol_bindings)
 
-    def _resolve_http_client(self) -> tuple[httpx.AsyncClient, bool]:
+    def _resolve_http_client(self) -> tuple[httpx2.AsyncClient, bool]:
         """Returns an HTTP client and whether it is shared across clients."""
         if self._config.httpx_client:
             return self._config.httpx_client, True
-        httpx_client = httpx.AsyncClient()
+        httpx_client = httpx2.AsyncClient()
         httpx_client.headers.setdefault(
             VERSION_HEADER, PROTOCOL_VERSION_CURRENT
         )