Add opt-in SDK logging

DemoApp/AssistantRuntimeDemoApp/Shared/AgentDemoRuntimeFactory.swift

@@ -73,6 +73,8 @@ enum AgentDemoRuntimeFactory {
         approvalInbox: ApprovalInbox,
         deviceCodePromptCoordinator: DeviceCodePromptCoordinator
     ) -> AgentRuntime {
+        let diagnostics = DemoDiagnostics()
+        let sdkLogging = diagnostics.sdkLoggingConfiguration()
         let authProvider: any ChatGPTAuthProviding
 
         switch authenticationMethod {
@@ -98,13 +100,21 @@ enum AgentDemoRuntimeFactory {
                 configuration: CodexResponsesBackendConfiguration(
                     model: model,
                     reasoningEffort: reasoningEffort,
-                    enableWebSearch: enableWebSearch
+                    enableWebSearch: enableWebSearch,
+                    logging: sdkLogging
                 )
             ),
             approvalPresenter: approvalInbox,
-            stateStore: try! GRDBRuntimeStateStore(url: stateURL ?? defaultStateURL()),
+            stateStore: try! GRDBRuntimeStateStore(
+                url: stateURL ?? defaultStateURL(),
+                logging: sdkLogging
+            ),
+            logging: sdkLogging,
             memory: .init(
-                store: try! SQLiteMemoryStore(url: defaultMemoryURL()),
+                store: try! SQLiteMemoryStore(
+                    url: defaultMemoryURL(),
+                    logging: sdkLogging
+                ),
                 automaticCapturePolicy: .init(
                     source: .lastTurn,
                     options: .init(
@@ -137,6 +147,8 @@ enum AgentDemoRuntimeFactory {
         reasoningEffort: ReasoningEffort = .medium,
         keychainAccount: String = defaultKeychainAccount
     ) -> AgentRuntime {
+        let diagnostics = DemoDiagnostics()
+        let sdkLogging = diagnostics.sdkLoggingConfiguration()
         let authProvider = try! ChatGPTAuthProvider(method: .oauth)
 
         return try! AgentRuntime(configuration: .init(
@@ -149,13 +161,21 @@ enum AgentDemoRuntimeFactory {
                 configuration: CodexResponsesBackendConfiguration(
                     model: model,
                     reasoningEffort: reasoningEffort,
-                    enableWebSearch: enableWebSearch
+                    enableWebSearch: enableWebSearch,
+                    logging: sdkLogging
                 )
             ),
             approvalPresenter: NonInteractiveApprovalPresenter(),
-            stateStore: try! GRDBRuntimeStateStore(url: defaultStateURL()),
+            stateStore: try! GRDBRuntimeStateStore(
+                url: defaultStateURL(),
+                logging: sdkLogging
+            ),
+            logging: sdkLogging,
             memory: .init(
-                store: try! SQLiteMemoryStore(url: defaultMemoryURL()),
+                store: try! SQLiteMemoryStore(
+                    url: defaultMemoryURL(),
+                    logging: sdkLogging
+                ),
                 automaticCapturePolicy: .init(
                     source: .lastTurn,
                     options: .init(

DemoApp/AssistantRuntimeDemoApp/Shared/AgentDemoView+ChatSections.swift

@@ -50,7 +50,7 @@ extension AgentDemoView {
             )
             .toggleStyle(.switch)
 
-            Text("Debug builds start with logging enabled. Logs print to the Xcode console for restore, sign-in, thread lifecycle, turn events, and tool activity.")
+            Text("Debug builds start with logging enabled. Logs print to the Xcode console for both demo actions and SDK internals like history writes, thread creation, network calls, retries, compaction, and tool activity.")
                 .font(.caption)
                 .foregroundStyle(.secondary)
 

DemoApp/AssistantRuntimeDemoApp/Shared/AgentDemoViewModel.swift

@@ -156,6 +156,10 @@ struct DemoDiagnostics {
 #endif
     }
 
+    func developerLoggingEnabled(userDefaults: UserDefaults = .standard) -> Bool {
+        initialDeveloperLoggingEnabled(userDefaults: userDefaults)
+    }
+
     func persistDeveloperLoggingEnabled(
         _ enabled: Bool,
         userDefaults: UserDefaults = .standard
@@ -176,6 +180,46 @@ struct DemoDiagnostics {
         logger.error("\(message, privacy: .public)")
         print("[CodexKit Demo][Error] \(message)")
     }
+
+    func sdkLoggingConfiguration() -> AgentLoggingConfiguration {
+        AgentLoggingConfiguration(
+            minimumLevel: .debug,
+            sink: DemoSDKLogSink(diagnostics: self)
+        )
+    }
+}
+
+struct DemoSDKLogSink: AgentLogSink {
+    let diagnostics: DemoDiagnostics
+
+    func log(_ entry: AgentLogEntry) {
+        guard diagnostics.developerLoggingEnabled() else {
+            return
+        }
+
+        let levelLabel: String
+        switch entry.level {
+        case .debug:
+            levelLabel = "DEBUG"
+        case .info:
+            levelLabel = "INFO"
+        case .warning:
+            levelLabel = "WARN"
+        case .error:
+            levelLabel = "ERROR"
+        }
+
+        var message = "[SDK][\(levelLabel)][\(entry.category.rawValue)] \(entry.message)"
+        if !entry.metadata.isEmpty {
+            let renderedMetadata = entry.metadata
+                .sorted { $0.key < $1.key }
+                .map { "\($0.key)=\($0.value)" }
+                .joined(separator: " ")
+            message += " | \(renderedMetadata)"
+        }
+
+        diagnostics.log(message)
+    }
 }
 
 @MainActor

README.md

@@ -20,6 +20,7 @@ Use `CodexKit` if you are building a SwiftUI app for iOS or macOS and want:
 - host-defined tools with approval gates
 - persona- and skill-aware agent behavior
 - hidden runtime context compaction with preserved user-visible history
+- opt-in developer logging across runtime, auth, backend, and bundled stores
 - share/import-friendly message construction
 
 The SDK stays tool-agnostic. Your app defines the tool surface and runtime UX.
@@ -227,12 +228,92 @@ let backend = CodexResponsesBackend(
 )
 ```
 
-Available values:
+## Developer Logging
 
-- `.low`
-- `.medium`
-- `.high`
-- `.extraHigh`
+`CodexKit` includes opt-in developer logging for the SDK itself. Logging is disabled by default and can be enabled independently on the runtime, built-in backend, and bundled stores.
+
+```swift
+let logging = AgentLoggingConfiguration.console(
+    minimumLevel: .debug
+)
+
+let backend = CodexResponsesBackend(
+    configuration: .init(
+        model: "gpt-5.4",
+        logging: logging
+    )
+)
+
+let stateStore = try GRDBRuntimeStateStore(
+    url: stateURL,
+    logging: logging
+)
+
+let runtime = try AgentRuntime(configuration: .init(
+    authProvider: authProvider,
+    secureStore: secureStore,
+    backend: backend,
+    approvalPresenter: approvalInbox,
+    stateStore: stateStore,
+    logging: logging
+))
+```
+
+You can also filter by category:
+
+```swift
+let logging = AgentLoggingConfiguration.osLog(
+    minimumLevel: .debug,
+    categories: [.runtime, .persistence, .network, .tools],
+    subsystem: "com.example.myapp"
+)
+```
+
+Available logging categories include:
+
+- `auth`
+- `runtime`
+- `persistence`
+- `network`
+- `retry`
+- `compaction`
+- `tools`
+- `approvals`
+- `structuredOutput`
+- `memory`
+
+Use `AgentConsoleLogSink` for stderr-style console logs, `AgentOSLogSink` for unified Apple logging, or provide your own `AgentLogSink`.
+
+Custom sinks make it possible to bridge `CodexKit` logs into your own telemetry or logging pipeline:
+
+```swift
+struct RemoteTelemetrySink: AgentLogSink {
+    func log(_ entry: AgentLogEntry) {
+        Telemetry.shared.enqueue(
+            level: entry.level,
+            category: entry.category.rawValue,
+            message: entry.message,
+            metadata: entry.metadata,
+            timestamp: entry.timestamp
+        )
+    }
+}
+
+let logging = AgentLoggingConfiguration(
+    minimumLevel: .info,
+    sink: RemoteTelemetrySink()
+)
+```
+
+`AgentLogEntry` includes:
+
+- timestamp
+- level
+- category
+- message
+- metadata
+
+For remote telemetry or file-backed logging, prefer a sink that buffers or enqueues work quickly. `AgentLogSink.log(_:)` is called inline, so it should avoid blocking network I/O on the caller's execution path.
 
 ## Persistent State And Queries
 

Sources/CodexKit/Auth/ChatGPTSessionManager.swift

@@ -3,20 +3,28 @@ import Foundation
 public actor ChatGPTSessionManager {
     private let authProvider: any ChatGPTAuthProviding
     private let secureStore: any SessionSecureStoring
+    private let logger: AgentLogger
     private var session: ChatGPTSession?
 
     public init(
         authProvider: any ChatGPTAuthProviding,
-        secureStore: any SessionSecureStoring
+        secureStore: any SessionSecureStoring,
+        logging: AgentLoggingConfiguration = .disabled
     ) {
         self.authProvider = authProvider
         self.secureStore = secureStore
+        self.logger = AgentLogger(configuration: logging)
     }
 
     @discardableResult
     public func restore() throws -> ChatGPTSession? {
         let restored = try secureStore.loadSession()
         session = restored
+        logger.debug(
+            .auth,
+            "Restored session from secure store.",
+            metadata: ["restored": "\(restored != nil)"]
+        )
         return restored
     }
 
@@ -29,15 +37,33 @@ public actor ChatGPTSessionManager {
         let signedInSession = try await authProvider.signInInteractively()
         try secureStore.saveSession(signedInSession)
         session = signedInSession
+        logger.info(
+            .auth,
+            "Persisted signed-in session.",
+            metadata: ["account_id": signedInSession.account.id]
+        )
         return signedInSession
     }
 
     @discardableResult
     public func refresh(reason: ChatGPTAuthRefreshReason) async throws -> ChatGPTSession {
         let current = try requireStoredSession()
+        logger.info(
+            .auth,
+            "Refreshing session.",
+            metadata: [
+                "reason": String(describing: reason),
+                "account_id": current.account.id
+            ]
+        )
         let refreshed = try await authProvider.refresh(session: current, reason: reason)
         try secureStore.saveSession(refreshed)
         session = refreshed
+        logger.info(
+            .auth,
+            "Session refresh completed.",
+            metadata: ["account_id": refreshed.account.id]
+        )
         return refreshed
     }
 
@@ -46,6 +72,11 @@ public actor ChatGPTSessionManager {
         session = nil
         try secureStore.deleteSession()
         await authProvider.signOut(session: current)
+        logger.info(
+            .auth,
+            "Session signed out.",
+            metadata: ["had_session": "\(current != nil)"]
+        )
     }
 
     public func requireSession() async throws -> ChatGPTSession {
@@ -61,11 +92,20 @@ public actor ChatGPTSessionManager {
     public func recoverUnauthorizedSession(
         previousAccessToken: String?
     ) async throws -> ChatGPTSession {
+        logger.warning(
+            .auth,
+            "Attempting unauthorized-session recovery."
+        )
         if let restored = try secureStore.loadSession() {
             session = restored
             if let previousAccessToken,
                restored.accessToken != previousAccessToken,
                !restored.requiresRefresh() {
+                logger.info(
+                    .auth,
+                    "Recovered session from secure store after unauthorized response.",
+                    metadata: ["account_id": restored.account.id]
+                )
                 return restored
             }
         }