diff --git a/src/bridge/remoteBridgeCore.ts b/src/bridge/remoteBridgeCore.ts
index d1886cc83..884f5eed4 100644
--- a/src/bridge/remoteBridgeCore.ts
+++ b/src/bridge/remoteBridgeCore.ts
@@ -69,8 +69,19 @@ import type {
   SDKControlRequest,
   SDKControlResponse,
 } from '../entrypoints/sdk/controlTypes.js'
+import type { StdoutMessage } from '../entrypoints/sdk/controlTypes.js'
+import type { SDKResultSuccess } from '../entrypoints/sdk/coreTypes.js'
 import type { PermissionMode } from '../utils/permissions/PermissionMode.js'
 
+/**
+ * StdoutMessage with session_id added. The transport layer adds session_id
+ * to messages at runtime, but the Zod schemas don't include it. This type
+ * makes it explicit that we're adding session_id to each message variant.
+ */
+type StdoutMessageWithSession = StdoutMessage extends infer T
+  ? T & { session_id: string }
+  : never
+
 const ANTHROPIC_VERSION = '2023-06-01'
 
 // Telemetry discriminator for ws_connected. 'initial' is the default and
@@ -608,7 +619,7 @@ export async function initEnvLessBridgeCore(
     const msgs = flushGate.end()
     if (msgs.length === 0) return
     for (const msg of msgs) recentPostedUUIDs.add(msg.uuid)
-    const events = toSDKMessages(msgs).map(m => ({
+    const events: StdoutMessageWithSession[] = toSDKMessages(msgs).map(m => ({
       ...m,
       session_id: sessionId,
     }))
@@ -636,7 +647,7 @@ export async function initEnvLessBridgeCore(
         `[remote-bridge] Capped initial flush: ${eligible.length} -> ${capped.length} (cap=${initialHistoryCap})`,
       )
     }
-    const events = toSDKMessages(capped).map(m => ({
+    const events: StdoutMessageWithSession[] = toSDKMessages(capped).map(m => ({
       ...m,
       session_id: sessionId,
     }))
@@ -675,8 +686,11 @@ export async function initEnvLessBridgeCore(
     // explicit sleep. close() sets closed=true which interrupts drain at the
     // next while-check, so close-before-archive drops the result.
     transport.reportState('idle')
-    void transport.write(makeResultMessage(sessionId))
-
+    const resultMsg: StdoutMessageWithSession = {
+      ...makeResultMessage(sessionId),
+      session_id: sessionId,
+    }
+    void transport.write(resultMsg)
     let token = getAccessToken()
     let status = await archiveSession(
       sessionId,
@@ -795,7 +809,7 @@ export async function initEnvLessBridgeCore(
       }
 
       for (const msg of filtered) recentPostedUUIDs.add(msg.uuid)
-      const events = toSDKMessages(filtered).map(m => ({
+      const events: StdoutMessageWithSession[] = toSDKMessages(filtered).map(m => ({
         ...m,
         session_id: sessionId,
       }))
@@ -818,7 +832,7 @@ export async function initEnvLessBridgeCore(
       for (const msg of filtered) {
         if (msg.uuid) recentPostedUUIDs.add(msg.uuid as string)
       }
-      const events = filtered.map(m => ({ ...m, session_id: sessionId }))
+      const events = filtered.map(m => ({ ...m, session_id: sessionId })) as StdoutMessage[]
       void transport.writeBatch(events)
     },
     sendControlRequest(request: SDKControlRequest) {
@@ -828,7 +842,7 @@ export async function initEnvLessBridgeCore(
         )
         return
       }
-      const event = { ...request, session_id: sessionId }
+      const event: StdoutMessageWithSession = { ...request, session_id: sessionId }
       if ((request as { request?: { subtype?: string } }).request?.subtype === 'can_use_tool') {
         transport.reportState('requires_action')
       }
@@ -844,7 +858,7 @@ export async function initEnvLessBridgeCore(
         )
         return
       }
-      const event = { ...response, session_id: sessionId }
+      const event: StdoutMessageWithSession = { ...response, session_id: sessionId }
       transport.reportState('running')
       void transport.write(event)
       logForDebugging('[remote-bridge] Sent control_response')
@@ -856,7 +870,7 @@ export async function initEnvLessBridgeCore(
         )
         return
       }
-      const event = {
+      const event: StdoutMessageWithSession = {
         type: 'control_cancel_request' as const,
         request_id: requestId,
         session_id: sessionId,
@@ -876,7 +890,11 @@ export async function initEnvLessBridgeCore(
         return
       }
       transport.reportState('idle')
-      void transport.write(makeResultMessage(sessionId))
+      const resultMsg: StdoutMessageWithSession = {
+        ...makeResultMessage(sessionId),
+        session_id: sessionId,
+      }
+      void transport.write(resultMsg)
       logForDebugging(`[remote-bridge] Sent result`)
     },
     async teardown() {
diff --git a/src/bridge/replBridge.ts b/src/bridge/replBridge.ts
index 7406bdde8..afab1be2e 100644
--- a/src/bridge/replBridge.ts
+++ b/src/bridge/replBridge.ts
@@ -53,6 +53,17 @@ import type {
   SDKControlRequest,
   SDKControlResponse,
 } from '../entrypoints/sdk/controlTypes.js'
+import type { StdoutMessage } from '../entrypoints/sdk/controlTypes.js'
+import type { SDKResultSuccess } from '../entrypoints/sdk/coreTypes.js'
+
+/**
+ * StdoutMessage with session_id added. The transport layer adds session_id
+ * to messages at runtime, but the Zod schemas don't include it. This type
+ * makes it explicit that we're adding session_id to each message variant.
+ */
+type StdoutMessageWithSession = StdoutMessage extends infer T
+  ? T & { session_id: string }
+  : never
 import { createCapacityWake, type CapacitySignal } from './capacityWake.js'
 import { FlushGate } from './flushGate.js'
 import {
@@ -865,7 +876,7 @@ export async function initBridgeCore(
       recentPostedUUIDs.add(msg.uuid)
     }
     const sdkMessages = toSDKMessages(msgs)
-    const events = sdkMessages.map(sdkMsg => ({
+    const events: StdoutMessageWithSession[] = sdkMessages.map(sdkMsg => ({
       ...sdkMsg,
       session_id: currentSessionId,
     }))
@@ -1285,7 +1296,7 @@ export async function initBridgeCore(
               logForDebugging(
                 `[bridge:repl] Flushing ${sdkMessages.length} initial message(s) via transport`,
               )
-              const events = sdkMessages.map(sdkMsg => ({
+              const events: StdoutMessageWithSession[] = sdkMessages.map(sdkMsg => ({
                 ...sdkMsg,
                 session_id: currentSessionId,
               }))
@@ -1655,7 +1666,11 @@ export async function initBridgeCore(
     transport = null
     flushGate.drop()
     if (teardownTransport) {
-      void teardownTransport.write(makeResultMessage(currentSessionId))
+      const resultMsg: StdoutMessageWithSession = {
+        ...makeResultMessage(currentSessionId),
+        session_id: currentSessionId,
+      }
+      void teardownTransport.write(resultMsg)
     }
 
     const stopWorkP = currentWorkId
@@ -1778,7 +1793,7 @@ export async function initBridgeCore(
       // Convert to SDK format and send via HTTP POST (HybridTransport).
       // The web UI receives them via the subscribe WebSocket.
       const sdkMessages = toSDKMessages(filtered)
-      const events = sdkMessages.map(sdkMsg => ({
+      const events: StdoutMessageWithSession[] = sdkMessages.map(sdkMsg => ({
         ...sdkMsg,
         session_id: currentSessionId,
       }))
@@ -1803,7 +1818,7 @@ export async function initBridgeCore(
       for (const msg of filtered) {
         if (msg.uuid) recentPostedUUIDs.add(msg.uuid as string)
       }
-      const events = filtered.map(m => ({ ...m, session_id: currentSessionId }))
+      const events: StdoutMessageWithSession[] = filtered.map(m => ({ ...m, session_id: currentSessionId }))
       void transport.writeBatch(events)
     },
     sendControlRequest(request: SDKControlRequest) {
@@ -1813,7 +1828,7 @@ export async function initBridgeCore(
         )
         return
       }
-      const event = { ...request, session_id: currentSessionId }
+      const event: StdoutMessageWithSession = { ...request, session_id: currentSessionId }
       void transport.write(event)
       logForDebugging(
         `[bridge:repl] Sent control_request request_id=${request.request_id}`,
@@ -1826,7 +1841,7 @@ export async function initBridgeCore(
         )
         return
       }
-      const event = { ...response, session_id: currentSessionId }
+      const event: StdoutMessageWithSession = { ...response, session_id: currentSessionId }
       void transport.write(event)
       logForDebugging('[bridge:repl] Sent control_response')
     },
@@ -1837,7 +1852,7 @@ export async function initBridgeCore(
         )
         return
       }
-      const event = {
+      const event: StdoutMessageWithSession = {
         type: 'control_cancel_request' as const,
         request_id: requestId,
         session_id: currentSessionId,
@@ -1854,7 +1869,11 @@ export async function initBridgeCore(
         )
         return
       }
-      void transport.write(makeResultMessage(currentSessionId))
+      const resultMsg: StdoutMessageWithSession = {
+        ...makeResultMessage(currentSessionId),
+        session_id: currentSessionId,
+      }
+      void transport.write(resultMsg)
       logForDebugging(
         `[bridge:repl] Sent result for session=${currentSessionId}`,
       )
diff --git a/src/cli/print.ts b/src/cli/print.ts
index 644753119..43d255637 100644
--- a/src/cli/print.ts
+++ b/src/cli/print.ts
@@ -1128,7 +1128,7 @@ function runHeadlessStreaming(
         rate_limit_info: rateLimitInfo,
         uuid: randomUUID(),
         session_id: getSessionId(),
-      })
+      } as unknown as Parameters<typeof output.enqueue>[0])
     }
   }
   statusListeners.add(rateLimitListener)
@@ -1237,7 +1237,7 @@ function runHeadlessStreaming(
           uuid: crumb.uuid,
           timestamp: crumb.timestamp,
           isReplay: true,
-        } as SDKUserMessageReplay)
+        } as SDKUserMessageReplay as StdoutMessage)
       }
     }
   }
@@ -1974,7 +1974,7 @@ function runHeadlessStreaming(
                   parent_tool_use_id: null,
                   uuid: c.uuid as string,
                   isReplay: true,
-                } as SDKUserMessageReplay)
+                } as SDKUserMessageReplay as StdoutMessage)
               }
             }
           }
@@ -2200,7 +2200,7 @@ function runHeadlessStreaming(
                 output.enqueue({
                   type: 'system',
                   subtype: 'status',
-                  status,
+                  status: status as 'compacting' | null,
                   session_id: getSessionId(),
                   uuid: randomUUID(),
                 })
@@ -2227,10 +2227,10 @@ function runHeadlessStreaming(
                       isBackgroundTask(t),
                   )
                 ) {
-                  heldBackResult = message
+                  heldBackResult = message as StdoutMessage
                 } else {
                   heldBackResult = null
-                  output.enqueue(message)
+                  output.enqueue(message as StdoutMessage)
                 }
               } else {
                 // Flush SDK events (task_started, task_progress) so background
@@ -2238,7 +2238,7 @@ function runHeadlessStreaming(
                 for (const event of drainSdkEvents()) {
                   output.enqueue(event)
                 }
-                output.enqueue(message)
+                output.enqueue(message as StdoutMessage)
               }
             }
           }) // end runWithWorkload
@@ -2256,11 +2256,12 @@ function runHeadlessStreaming(
               { turnStartTime } as import('src/utils/filePersistence/types.js').TurnStartTime,
               abortController.signal,
               result => {
+                const filesResult = result as { persistedFiles: { filename: string; file_id: string }[]; failedFiles: { filename: string; error: string }[] }
                 output.enqueue({
                   type: 'system' as const,
                   subtype: 'files_persisted' as const,
-                  files: (result as any).persistedFiles,
-                  failed: (result as any).failedFiles,
+                  files: filesResult.persistedFiles,
+                  failed: filesResult.failedFiles,
                   processed_at: new Date().toISOString(),
                   uuid: randomUUID(),
                   session_id: getSessionId(),
@@ -2730,7 +2731,7 @@ function runHeadlessStreaming(
   }
 
   const sendControlResponseSuccess = function (
-    message: SDKControlRequest,
+    message: { request_id: string } | SDKControlRequest,
     response?: Record<string, unknown>,
   ) {
     output.enqueue({
@@ -2744,7 +2745,7 @@ function runHeadlessStreaming(
   }
 
   const sendControlResponseError = function (
-    message: SDKControlRequest,
+    message: { request_id: string } | SDKControlRequest,
     errorMessage: string,
   ) {
     output.enqueue({
@@ -2820,11 +2821,21 @@ function runHeadlessStreaming(
         message.type !== 'user' &&
         message.type !== 'control_response'
       ) {
-        notifyCommandLifecycle(eventId, 'completed')
+        notifyCommandLifecycle(eventId as string, 'completed')
       }
 
       if (message.type === 'control_request') {
-        if (message.request.subtype === 'interrupt') {
+        // Type assertion: structuredInput yields StdinMessage | SDKMessage, but
+        // when type === 'control_request' the object has request_id and request.
+        // The union with SDKMessage (typed as `any`) causes request to be `unknown`.
+        // Cast to SDKControlRequest (via unknown) for type safety on known subtypes,
+        // and use Record<string, unknown> for subtypes not in the zod schema union.
+        const msg = message as unknown as SDKControlRequest
+        // Wider-typed alias for request properties on subtypes not in the zod schema.
+        // The schema union doesn't include end_session, channel_enable, mcp_authenticate,
+        // claude_authenticate, etc. so accessing their properties narrows to `never`.
+        const req = msg.request as Record<string, unknown>
+        if (msg.request.subtype === 'interrupt') {
           // Track escapes for attribution (ant-only feature)
           if (feature('COMMIT_ATTRIBUTION')) {
             setAppState(prev => ({
@@ -2842,10 +2853,10 @@ function runHeadlessStreaming(
           suggestionState.abortController = null
           suggestionState.lastEmitted = null
           suggestionState.pendingSuggestion = null
-          sendControlResponseSuccess(message)
-        } else if (message.request.subtype === 'end_session') {
+          sendControlResponseSuccess(msg)
+        } else if (req.subtype === 'end_session') {
           logForDebugging(
-            `[print.ts] end_session received, reason=${message.request.reason ?? 'unspecified'}`,
+            `[print.ts] end_session received, reason=${req.reason ?? 'unspecified'}`,
           )
           if (abortController) {
             abortController.abort()
@@ -2854,16 +2865,16 @@ function runHeadlessStreaming(
           suggestionState.abortController = null
           suggestionState.lastEmitted = null
           suggestionState.pendingSuggestion = null
-          sendControlResponseSuccess(message)
+          sendControlResponseSuccess(msg)
           break // exits for-await → falls through to inputClosed=true drain below
-        } else if (message.request.subtype === 'initialize') {
+        } else if (msg.request.subtype === 'initialize') {
           // SDK MCP server names from the initialize message
           // Populated by both browser and ProcessTransport sessions
           if (
-            message.request.sdkMcpServers &&
-            message.request.sdkMcpServers.length > 0
+            msg.request.sdkMcpServers &&
+            msg.request.sdkMcpServers.length > 0
           ) {
-            for (const serverName of message.request.sdkMcpServers) {
+            for (const serverName of msg.request.sdkMcpServers) {
               // Create placeholder config for SDK MCP servers
               // The actual server connection is managed by the SDK Query class
               sdkMcpConfigs[serverName] = {
@@ -2874,8 +2885,8 @@ function runHeadlessStreaming(
           }
 
           await handleInitializeRequest(
-            message.request,
-            message.request_id,
+            msg.request,
+            msg.request_id,
             initialized,
             output,
             commands,
@@ -2890,7 +2901,7 @@ function runHeadlessStreaming(
           // Enable prompt suggestions in AppState when SDK consumer opts in.
           // shouldEnablePromptSuggestion() returns false for non-interactive
           // sessions, but the SDK consumer explicitly requested suggestions.
-          if (message.request.promptSuggestions) {
+          if (msg.request.promptSuggestions) {
             setAppState(prev => {
               if (prev.promptSuggestionEnabled) return prev
               return { ...prev, promptSuggestionEnabled: true }
@@ -2898,7 +2909,7 @@ function runHeadlessStreaming(
           }
 
           if (
-            message.request.agentProgressSummaries &&
+            msg.request.agentProgressSummaries &&
             getFeatureValue_CACHED_MAY_BE_STALE('tengu_slate_prism', true)
           ) {
             setSdkAgentProgressSummariesEnabled(true)
@@ -2911,13 +2922,13 @@ function runHeadlessStreaming(
           if (hasCommandsInQueue()) {
             void run()
           }
-        } else if (message.request.subtype === 'set_permission_mode') {
-          const m = message.request // for typescript (TODO: use readonly types to avoid this)
+        } else if (msg.request.subtype === 'set_permission_mode') {
+          const m = msg.request // for typescript (TODO: use readonly types to avoid this)
           setAppState(prev => ({
             ...prev,
             toolPermissionContext: handleSetPermissionMode(
               m,
-              message.request_id,
+              msg.request_id,
               prev.toolPermissionContext,
               output,
             ),
@@ -2926,8 +2937,8 @@ function runHeadlessStreaming(
           // handleSetPermissionMode sends the control_response; the
           // notifySessionMetadataChanged that used to follow here is
           // now fired by onChangeAppState (with externalized mode name).
-        } else if (message.request.subtype === 'set_model') {
-          const requestedModel = message.request.model ?? 'default'
+        } else if (msg.request.subtype === 'set_model') {
+          const requestedModel = msg.request.model ?? 'default'
           const model =
             requestedModel === 'default'
               ? getDefaultMainLoopModel()
@@ -2937,24 +2948,24 @@ function runHeadlessStreaming(
           notifySessionMetadataChanged({ model })
           injectModelSwitchBreadcrumbs(requestedModel, model)
 
-          sendControlResponseSuccess(message)
-        } else if (message.request.subtype === 'set_max_thinking_tokens') {
-          if (message.request.max_thinking_tokens === null) {
+          sendControlResponseSuccess(msg)
+        } else if (msg.request.subtype === 'set_max_thinking_tokens') {
+          if (msg.request.max_thinking_tokens === null) {
             options.thinkingConfig = undefined
-          } else if (message.request.max_thinking_tokens === 0) {
+          } else if (msg.request.max_thinking_tokens === 0) {
             options.thinkingConfig = { type: 'disabled' }
           } else {
             options.thinkingConfig = {
               type: 'enabled',
-              budgetTokens: message.request.max_thinking_tokens,
+              budgetTokens: msg.request.max_thinking_tokens,
             }
           }
-          sendControlResponseSuccess(message)
-        } else if (message.request.subtype === 'mcp_status') {
-          sendControlResponseSuccess(message, {
+          sendControlResponseSuccess(msg)
+        } else if (msg.request.subtype === 'mcp_status') {
+          sendControlResponseSuccess(msg, {
             mcpServers: buildMcpServerStatuses(),
           })
-        } else if (message.request.subtype === 'get_context_usage') {
+        } else if (msg.request.subtype === 'get_context_usage') {
           try {
             const appState = getAppState()
             const data = await collectContextData({
@@ -2968,13 +2979,13 @@ function runHeadlessStreaming(
                 appendSystemPrompt: options.appendSystemPrompt,
               },
             })
-            sendControlResponseSuccess(message, { ...data })
+            sendControlResponseSuccess(msg, { ...data })
           } catch (error) {
-            sendControlResponseError(message, errorMessage(error))
+            sendControlResponseError(msg, errorMessage(error))
           }
-        } else if (message.request.subtype === 'mcp_message') {
+        } else if (msg.request.subtype === 'mcp_message') {
           // Handle MCP notifications from SDK servers
-          const mcpRequest = message.request
+          const mcpRequest = msg.request as Record<string, unknown>
           const sdkClient = sdkClients.find(
             client => client.name === mcpRequest.server_name,
           )
@@ -2985,32 +2996,32 @@ function runHeadlessStreaming(
             sdkClient.type === 'connected' &&
             sdkClient.client?.transport?.onmessage
           ) {
-            sdkClient.client.transport.onmessage(mcpRequest.message)
+            sdkClient.client.transport.onmessage(mcpRequest.message as import('@modelcontextprotocol/sdk/types.js').JSONRPCMessage)
           }
-          sendControlResponseSuccess(message)
-        } else if (message.request.subtype === 'rewind_files') {
+          sendControlResponseSuccess(msg)
+        } else if (msg.request.subtype === 'rewind_files') {
           const appState = getAppState()
           const result = await handleRewindFiles(
-            message.request.user_message_id as UUID,
+            msg.request.user_message_id as UUID,
             appState,
             setAppState,
-            message.request.dry_run ?? false,
+            msg.request.dry_run ?? false,
           )
-          if (result.canRewind || message.request.dry_run) {
-            sendControlResponseSuccess(message, result)
+          if (result.canRewind || msg.request.dry_run) {
+            sendControlResponseSuccess(msg, result)
           } else {
             sendControlResponseError(
-              message,
+              msg,
               (result.error as string) ?? 'Unexpected error',
             )
           }
-        } else if (message.request.subtype === 'cancel_async_message') {
-          const targetUuid = message.request.message_uuid
+        } else if (msg.request.subtype === 'cancel_async_message') {
+          const targetUuid = msg.request.message_uuid
           const removed = dequeueAllMatching(cmd => cmd.uuid === targetUuid)
-          sendControlResponseSuccess(message, {
+          sendControlResponseSuccess(msg, {
             cancelled: removed.length > 0,
           })
-        } else if (message.request.subtype === 'seed_read_state') {
+        } else if (msg.request.subtype === 'seed_read_state') {
           // Client observed a Read that was later removed from context (e.g.
           // by snip), so transcript-based seeding missed it. Queued into
           // pendingSeeds; applied at the next clone-replace boundary.
@@ -3018,7 +3029,7 @@ function runHeadlessStreaming(
             // expandPath: all other readFileState writers normalize (~, relative,
             // session cwd vs process cwd). FileEditTool looks up by expandPath'd
             // key — a verbatim client path would miss.
-            const normalizedPath = expandPath(message.request.path)
+            const normalizedPath = expandPath(msg.request.path)
             // Check disk mtime before reading content. If the file changed
             // since the client's observation, readFile would return C_current
             // but we'd store it with the client's M_observed — getChangedFiles
@@ -3028,7 +3039,7 @@ function runHeadlessStreaming(
             // makes Edit fail "file not read yet" → forces a fresh Read.
             // Math.floor matches FileReadTool and getFileModificationTime.
             const diskMtime = Math.floor((await stat(normalizedPath)).mtimeMs)
-            if (diskMtime <= message.request.mtime) {
+            if (diskMtime <= msg.request.mtime) {
               const raw = await readFile(normalizedPath, 'utf-8')
               // Strip BOM + normalize CRLF→LF to match readFileInRange and
               // readFileSyncWithMetadata. FileEditTool's content-compare
@@ -3047,18 +3058,18 @@ function runHeadlessStreaming(
           } catch {
             // ENOENT etc — skip seeding but still succeed
           }
-          sendControlResponseSuccess(message)
-        } else if (message.request.subtype === 'mcp_set_servers') {
+          sendControlResponseSuccess(msg)
+        } else if (msg.request.subtype === 'mcp_set_servers') {
           const { response, sdkServersChanged } = await applyMcpServerChanges(
-            message.request.servers,
+            msg.request.servers as Record<string, McpServerConfigForProcessTransport>,
           )
-          sendControlResponseSuccess(message, response)
+          sendControlResponseSuccess(msg, response)
 
           // Connect SDK servers AFTER response to avoid deadlock
           if (sdkServersChanged) {
             void updateSdkMcp()
           }
-        } else if (message.request.subtype === 'reload_plugins') {
+        } else if (msg.request.subtype === 'reload_plugins') {
           try {
             if (
               feature('DOWNLOAD_USER_SETTINGS') &&
@@ -3106,7 +3117,7 @@ function runHeadlessStreaming(
               logError(pluginsR.reason)
             }
 
-            sendControlResponseSuccess(message, {
+            sendControlResponseSuccess(msg, {
               commands: currentCommands
                 .filter(cmd => cmd.userInvocable !== false)
                 .map(cmd => ({
@@ -3120,15 +3131,15 @@ function runHeadlessStreaming(
                 model: a.model === 'inherit' ? undefined : a.model,
               })),
               plugins,
-              mcpServers: buildMcpServerStatuses(),
+              mcpServers: buildMcpServerStatuses() as SDKControlReloadPluginsResponse['mcpServers'],
               error_count: r.error_count,
             } satisfies SDKControlReloadPluginsResponse)
           } catch (error) {
-            sendControlResponseError(message, errorMessage(error))
+            sendControlResponseError(msg, errorMessage(error))
           }
-        } else if (message.request.subtype === 'mcp_reconnect') {
+        } else if (msg.request.subtype === 'mcp_reconnect') {
           const currentAppState = getAppState()
-          const { serverName } = message.request
+          const { serverName } = msg.request
           elicitationRegistered.delete(serverName)
           // Config-existence gate must cover the SAME sources as the
           // operations below. SDK-injected servers (query({mcpServers:{...}}))
@@ -3144,7 +3155,7 @@ function runHeadlessStreaming(
               ?.config ??
             null
           if (!config) {
-            sendControlResponseError(message, `Server not found: ${serverName}`)
+            sendControlResponseError(msg, `Server not found: ${serverName}`)
           } else {
             const result = await reconnectMcpServerImpl(serverName, config)
             // Update appState.mcp with the new client, tools, commands, and resources
@@ -3190,18 +3201,18 @@ function runHeadlessStreaming(
             if (result.client.type === 'connected') {
               registerElicitationHandlers([result.client])
               reregisterChannelHandlerAfterReconnect(result.client)
-              sendControlResponseSuccess(message)
+              sendControlResponseSuccess(msg)
             } else {
               const errorMessage =
                 result.client.type === 'failed'
                   ? (result.client.error ?? 'Connection failed')
                   : `Server status: ${result.client.type}`
-              sendControlResponseError(message, errorMessage)
+              sendControlResponseError(msg, errorMessage)
             }
           }
-        } else if (message.request.subtype === 'mcp_toggle') {
+        } else if (msg.request.subtype === 'mcp_toggle') {
           const currentAppState = getAppState()
-          const { serverName, enabled } = message.request
+          const { serverName, enabled } = msg.request
           elicitationRegistered.delete(serverName)
           // Gate must match the client-lookup spread below (which
           // includes sdkClients and dynamicMcpState.clients). Same fix as
@@ -3216,7 +3227,7 @@ function runHeadlessStreaming(
             null
 
           if (!config) {
-            sendControlResponseError(message, `Server not found: ${serverName}`)
+            sendControlResponseError(msg, `Server not found: ${serverName}`)
           } else if (!enabled) {
             // Disabling: persist + disconnect (matches TUI toggleMcpServer behavior)
             setMcpServerEnabled(serverName, false)
@@ -3247,7 +3258,7 @@ function runHeadlessStreaming(
                 resources: omit(prev.mcp.resources, serverName),
               },
             }))
-            sendControlResponseSuccess(message)
+            sendControlResponseSuccess(msg)
           } else {
             // Enabling: persist + reconnect
             setMcpServerEnabled(serverName, true)
@@ -3281,20 +3292,20 @@ function runHeadlessStreaming(
             if (result.client.type === 'connected') {
               registerElicitationHandlers([result.client])
               reregisterChannelHandlerAfterReconnect(result.client)
-              sendControlResponseSuccess(message)
+              sendControlResponseSuccess(msg)
             } else {
               const errorMessage =
                 result.client.type === 'failed'
                   ? (result.client.error ?? 'Connection failed')
                   : `Server status: ${result.client.type}`
-              sendControlResponseError(message, errorMessage)
+              sendControlResponseError(msg, errorMessage)
             }
           }
-        } else if (message.request.subtype === 'channel_enable') {
+        } else if (req.subtype === 'channel_enable') {
           const currentAppState = getAppState()
           handleChannelEnable(
-            message.request_id,
-            message.request.serverName,
+            msg.request_id,
+            req.serverName as string,
             // Pool spread matches mcp_status — all three client sources.
             [
               ...currentAppState.mcp.clients,
@@ -3303,8 +3314,8 @@ function runHeadlessStreaming(
             ],
             output,
           )
-        } else if (message.request.subtype === 'mcp_authenticate') {
-          const { serverName } = message.request
+        } else if (req.subtype === 'mcp_authenticate') {
+          const { serverName } = req
           const currentAppState = getAppState()
           const config =
             getMcpConfigByName(serverName) ??
@@ -3313,10 +3324,10 @@ function runHeadlessStreaming(
               ?.config ??
             null
           if (!config) {
-            sendControlResponseError(message, `Server not found: ${serverName}`)
+            sendControlResponseError(msg, `Server not found: ${serverName}`)
           } else if (config.type !== 'sse' && config.type !== 'http') {
             sendControlResponseError(
-              message,
+              msg,
               `Server type "${config.type}" does not support OAuth authentication`,
             )
           } else {
@@ -3353,12 +3364,12 @@ function runHeadlessStreaming(
               ])
 
               if (authUrl) {
-                sendControlResponseSuccess(message, {
+                sendControlResponseSuccess(msg, {
                   authUrl,
                   requiresUserAction: true,
                 })
               } else {
-                sendControlResponseSuccess(message, {
+                sendControlResponseSuccess(msg, {
                   requiresUserAction: false,
                 })
               }
@@ -3453,11 +3464,11 @@ function runHeadlessStreaming(
                 })
               void fullFlowPromise
             } catch (error) {
-              sendControlResponseError(message, errorMessage(error))
+              sendControlResponseError(msg, errorMessage(error))
             }
           }
-        } else if (message.request.subtype === 'mcp_oauth_callback_url') {
-          const { serverName, callbackUrl } = message.request
+        } else if (req.subtype === 'mcp_oauth_callback_url') {
+          const { serverName, callbackUrl } = req
           const submit = oauthCallbackSubmitters.get(serverName)
           if (submit) {
             // Validate the callback URL before submitting. The submit
@@ -3475,7 +3486,7 @@ function runHeadlessStreaming(
             }
             if (!hasCodeOrError) {
               sendControlResponseError(
-                message,
+                msg,
                 'Invalid callback URL: missing authorization code. Please paste the full redirect URL including the code parameter.',
               )
             } else {
@@ -3488,32 +3499,32 @@ function runHeadlessStreaming(
               if (authPromise) {
                 try {
                   await authPromise
-                  sendControlResponseSuccess(message)
+                  sendControlResponseSuccess(msg)
                 } catch (error) {
                   sendControlResponseError(
-                    message,
+                    msg,
                     error instanceof Error
                       ? error.message
                       : 'OAuth authentication failed',
                   )
                 }
               } else {
-                sendControlResponseSuccess(message)
+                sendControlResponseSuccess(msg)
               }
             }
           } else {
             sendControlResponseError(
-              message,
+              msg,
               `No active OAuth flow for server: ${serverName}`,
             )
           }
-        } else if (message.request.subtype === 'claude_authenticate') {
+        } else if (req.subtype === 'claude_authenticate') {
           // Anthropic OAuth over the control channel. The SDK client owns
           // the user's browser (we're headless in -p mode); we hand back
           // both URLs and wait. Automatic URL → localhost listener catches
           // the redirect if the browser is on this host; manual URL → the
           // success page shows "code#state" for claude_oauth_callback.
-          const { loginWithClaudeAi } = message.request
+          const { loginWithClaudeAi } = req
 
           // Clean up any prior flow. cleanup() closes the localhost listener
           // and nulls the manual resolver. The prior `flow` promise is left
@@ -3594,30 +3605,30 @@ function runHeadlessStreaming(
                 )
               }),
             ])
-            sendControlResponseSuccess(message, {
+            sendControlResponseSuccess(msg, {
               manualUrl,
               automaticUrl,
             })
           } catch (error) {
-            sendControlResponseError(message, errorMessage(error))
+            sendControlResponseError(msg, errorMessage(error))
           }
         } else if (
-          message.request.subtype === 'claude_oauth_callback' ||
-          message.request.subtype === 'claude_oauth_wait_for_completion'
+          req.subtype === 'claude_oauth_callback' ||
+          req.subtype === 'claude_oauth_wait_for_completion'
         ) {
           if (!claudeOAuth) {
             sendControlResponseError(
-              message,
+              msg,
               'No active claude_authenticate flow',
             )
           } else {
             // Inject the manual code synchronously — must happen in stdin
             // message order so a subsequent claude_authenticate doesn't
             // replace the service before this code lands.
-            if (message.request.subtype === 'claude_oauth_callback') {
+            if (req.subtype === 'claude_oauth_callback') {
               claudeOAuth.service.handleManualAuthCodeInput({
-                authorizationCode: message.request.authorizationCode,
-                state: message.request.state,
+                authorizationCode: req.authorizationCode as string,
+                state: req.state as string,
               })
             }
             // Detach the await — the stdin reader is serial and blocking
@@ -3629,7 +3640,7 @@ function runHeadlessStreaming(
             void flow.then(
               () => {
                 const accountInfo = getAccountInformation()
-                sendControlResponseSuccess(message, {
+                sendControlResponseSuccess(msg, {
                   account: {
                     email: accountInfo?.email,
                     organization: accountInfo?.organization,
@@ -3641,11 +3652,11 @@ function runHeadlessStreaming(
                 })
               },
               (error: unknown) =>
-                sendControlResponseError(message, errorMessage(error)),
+                sendControlResponseError(msg, errorMessage(error)),
             )
           }
-        } else if (message.request.subtype === 'mcp_clear_auth') {
-          const { serverName } = message.request
+        } else if (req.subtype === 'mcp_clear_auth') {
+          const { serverName } = req
           const currentAppState = getAppState()
           const config =
             getMcpConfigByName(serverName) ??
@@ -3654,10 +3665,10 @@ function runHeadlessStreaming(
               ?.config ??
             null
           if (!config) {
-            sendControlResponseError(message, `Server not found: ${serverName}`)
+            sendControlResponseError(msg, `Server not found: ${serverName}`)
           } else if (config.type !== 'sse' && config.type !== 'http') {
             sendControlResponseError(
-              message,
+              msg,
               `Cannot clear auth for server type "${config.type}"`,
             )
           } else {
@@ -3690,16 +3701,16 @@ function runHeadlessStreaming(
                     : omit(prev.mcp.resources, serverName),
               },
             }))
-            sendControlResponseSuccess(message, {})
+            sendControlResponseSuccess(msg, {})
           }
-        } else if (message.request.subtype === 'apply_flag_settings') {
+        } else if (msg.request.subtype === 'apply_flag_settings') {
           // Snapshot the current model before applying — we need to detect
           // model switches so we can inject breadcrumbs and notify listeners.
           const prevModel = getMainLoopModel()
 
           // Merge the provided settings into the in-memory flag settings
           const existing = getFlagSettingsInline() ?? {}
-          const incoming = message.request.settings
+          const incoming = msg.request.settings
           // Shallow-merge top-level keys; getSettingsForSource handles
           // the deep merge with file-based flag settings via mergeWith.
           // JSON serialization drops `undefined`, so callers use `null`
@@ -3748,8 +3759,8 @@ function runHeadlessStreaming(
             injectModelSwitchBreadcrumbs(modelArg, newModel)
           }
 
-          sendControlResponseSuccess(message)
-        } else if (message.request.subtype === 'get_settings') {
+          sendControlResponseSuccess(msg)
+        } else if (msg.request.subtype === 'get_settings') {
           const currentAppState = getAppState()
           const model = getMainLoopModel()
           // modelSupportsEffort gate matches claude.ts — applied.effort must
@@ -3757,7 +3768,7 @@ function runHeadlessStreaming(
           const effort = modelSupportsEffort(model)
             ? resolveAppliedEffort(model, currentAppState.effortValue)
             : undefined
-          sendControlResponseSuccess(message, {
+          sendControlResponseSuccess(msg, {
             ...getSettingsWithSources(),
             applied: {
               model,
@@ -3765,22 +3776,22 @@ function runHeadlessStreaming(
               effort: typeof effort === 'string' ? effort : null,
             },
           })
-        } else if (message.request.subtype === 'stop_task') {
-          const { task_id: taskId } = message.request
+        } else if (msg.request.subtype === 'stop_task') {
+          const { task_id: taskId } = msg.request
           try {
             await stopTask(taskId, {
               getAppState,
               setAppState,
             })
-            sendControlResponseSuccess(message, {})
+            sendControlResponseSuccess(msg, {})
           } catch (error) {
-            sendControlResponseError(message, errorMessage(error))
+            sendControlResponseError(msg, errorMessage(error))
           }
-        } else if (message.request.subtype === 'generate_session_title') {
+        } else if (req.subtype === 'generate_session_title') {
           // Fire-and-forget so the Haiku call does not block the stdin loop
           // (which would delay processing of subsequent user messages /
           // interrupts for the duration of the API roundtrip).
-          const { description, persist } = message.request
+          const { description, persist } = req
           // Reuse the live controller only if it has not already been aborted
           // (e.g. by interrupt()); an aborted signal would cause queryHaiku to
           // immediately throw APIUserAbortError → {title: null}.
@@ -3799,16 +3810,16 @@ function runHeadlessStreaming(
                   logError(e)
                 }
               }
-              sendControlResponseSuccess(message, { title })
+              sendControlResponseSuccess(msg, { title })
             } catch (e) {
               // Unreachable in practice — generateSessionTitle wraps its
               // own body and returns null, saveAiGeneratedTitle is wrapped
               // above. Propagate (not swallow) so unexpected failures are
               // visible to the SDK caller (hostComms.ts catches and logs).
-              sendControlResponseError(message, errorMessage(e))
+              sendControlResponseError(msg, errorMessage(e))
             }
           })()
-        } else if (message.request.subtype === 'side_question') {
+        } else if (req.subtype === 'side_question') {
           // Same fire-and-forget pattern as generate_session_title above —
           // the forked agent's API roundtrip must not block the stdin loop.
           //
@@ -3824,7 +3835,7 @@ function runHeadlessStreaming(
           // matches in the common case. May still miss the cache for
           // coordinator mode or memory-mechanics extras — acceptable, the
           // alternative is the side question failing entirely.
-          const { question } = message.request
+          const { question } = req
           void (async () => {
             try {
               const saved = getLastCacheSafeParams()
@@ -3863,16 +3874,16 @@ function runHeadlessStreaming(
                 question,
                 cacheSafeParams,
               })
-              sendControlResponseSuccess(message, { response: result.response })
+              sendControlResponseSuccess(msg, { response: result.response })
             } catch (e) {
-              sendControlResponseError(message, errorMessage(e))
+              sendControlResponseError(msg, errorMessage(e))
             }
           })()
         } else if (
           (feature('PROACTIVE') || feature('KAIROS')) &&
-          (message.request as { subtype: string }).subtype === 'set_proactive'
+          (msg.request as { subtype: string }).subtype === 'set_proactive'
         ) {
-          const req = message.request as unknown as {
+          const req = msg.request as unknown as {
             subtype: string
             enabled: boolean
           }
@@ -3884,12 +3895,12 @@ function runHeadlessStreaming(
           } else {
             proactiveModule!.deactivateProactive()
           }
-          sendControlResponseSuccess(message)
-        } else if (message.request.subtype === 'remote_control') {
-          if (message.request.enabled) {
+          sendControlResponseSuccess(msg)
+        } else if (req.subtype === 'remote_control') {
+          if (req.enabled as boolean) {
             if (bridgeHandle) {
               // Already connected
-              sendControlResponseSuccess(message, {
+              sendControlResponseSuccess(msg, {
                 session_url: getRemoteSessionUrl(
                   bridgeHandle.bridgeSessionId,
                   bridgeHandle.sessionIngressUrl,
@@ -3972,7 +3983,7 @@ function runHeadlessStreaming(
                 })
                 if (!handle) {
                   sendControlResponseError(
-                    message,
+                    msg,
                     bridgeFailureDetail ??
                       'Remote Control initialization failed',
                   )
@@ -3988,7 +3999,7 @@ function runHeadlessStreaming(
                   structuredIO.setOnControlRequestResolved(requestId => {
                     handle.sendControlCancelRequest(requestId)
                   })
-                  sendControlResponseSuccess(message, {
+                  sendControlResponseSuccess(msg, {
                     session_url: getRemoteSessionUrl(
                       handle.bridgeSessionId,
                       handle.sessionIngressUrl,
@@ -4001,7 +4012,7 @@ function runHeadlessStreaming(
                   })
                 }
               } catch (err) {
-                sendControlResponseError(message, errorMessage(err))
+                sendControlResponseError(msg, errorMessage(err))
               }
             }
           } else {
@@ -4012,21 +4023,21 @@ function runHeadlessStreaming(
               await bridgeHandle.teardown()
               bridgeHandle = null
             }
-            sendControlResponseSuccess(message)
+            sendControlResponseSuccess(msg)
           }
         } else {
           // Unknown control request subtype — send an error response so
           // the caller doesn't hang waiting for a reply that never comes.
           sendControlResponseError(
-            message,
-            `Unsupported control request subtype: ${(message.request as { subtype: string }).subtype}`,
+            msg,
+            `Unsupported control request subtype: ${(msg.request as { subtype: string }).subtype}`,
           )
         }
         continue
       } else if (message.type === 'control_response') {
         // Replay control_response messages when replay mode is enabled
         if (options.replayUserMessages) {
-          output.enqueue(message)
+          output.enqueue(message as StdoutMessage)
         }
         continue
       } else if (message.type === 'keep_alive') {
@@ -4038,11 +4049,11 @@ function runHeadlessStreaming(
       } else if (message.type === 'assistant' || message.type === 'system') {
         // History replay from bridge: inject into mutableMessages as
         // conversation context so the model sees prior turns.
-        const internalMsgs = toInternalMessages([message])
+        const internalMsgs = toInternalMessages([message as SDKMessage])
         mutableMessages.push(...internalMsgs)
         // Echo assistant messages back so CCR displays them
         if (message.type === 'assistant' && options.replayUserMessages) {
-          output.enqueue(message)
+          output.enqueue(message as StdoutMessage)
         }
         continue
       }
@@ -4051,58 +4062,61 @@ function runHeadlessStreaming(
       if (message.type !== 'user') {
         continue
       }
+      // Type assertion: after the type guard, message is a user message.
+      // The union with SDKMessage (any) prevents proper narrowing.
+      const userMsg = message as SDKUserMessage
 
       // First prompt message implicitly initializes if not already done.
       initialized = true
 
       // Check for duplicate user message - skip if already processed
-      if (message.uuid) {
+      if (userMsg.uuid) {
         const sessionId = getSessionId() as UUID
         const existsInSession = await doesMessageExistInSession(
           sessionId,
-          message.uuid,
+          userMsg.uuid as UUID,
         )
 
         // Check both historical duplicates (from file) and runtime duplicates (this session)
-        if (existsInSession || receivedMessageUuids.has(message.uuid)) {
-          logForDebugging(`Skipping duplicate user message: ${message.uuid}`)
+        if (existsInSession || receivedMessageUuids.has(userMsg.uuid as UUID)) {
+          logForDebugging(`Skipping duplicate user message: ${userMsg.uuid}`)
           // Send acknowledgment for duplicate message if replay mode is enabled
           if (options.replayUserMessages) {
             logForDebugging(
-              `Sending acknowledgment for duplicate user message: ${message.uuid}`,
+              `Sending acknowledgment for duplicate user message: ${userMsg.uuid}`,
             )
             output.enqueue({
               type: 'user',
-              content: message.message?.content ?? '',
-              message: message.message,
+              content: (userMsg.message as { content?: string })?.content ?? '',
+              message: userMsg.message as { role: string; content: unknown },
               session_id: sessionId,
               parent_tool_use_id: null,
-              uuid: message.uuid,
-              timestamp: message.timestamp,
+              uuid: userMsg.uuid as string,
+              timestamp: (userMsg as { timestamp?: string }).timestamp,
               isReplay: true,
-            } as unknown as SDKUserMessageReplay)
+            } as unknown as SDKUserMessageReplay as StdoutMessage)
           }
           // Historical dup = transcript already has this turn's output, so it
           // ran but its lifecycle was never closed (interrupted before ack).
           // Runtime dups don't need this — the original enqueue path closes them.
           if (existsInSession) {
-            notifyCommandLifecycle(message.uuid, 'completed')
+            notifyCommandLifecycle(userMsg.uuid as string, 'completed')
           }
           // Don't enqueue duplicate messages for execution
           continue
         }
 
         // Track this UUID to prevent runtime duplicates
-        trackReceivedMessageUuid(message.uuid)
+        trackReceivedMessageUuid(userMsg.uuid as UUID)
       }
 
       enqueue({
         mode: 'prompt' as const,
         // file_attachments rides the protobuf catchall from the web composer.
         // Same-ref no-op when absent (no 'file_attachments' key).
-        value: await resolveAndPrepend(message, message.message.content),
-        uuid: message.uuid,
-        priority: message.priority,
+        value: await resolveAndPrepend(userMsg, (userMsg.message as { content: ContentBlockParam[] }).content),
+        uuid: userMsg.uuid as `${string}-${string}-${string}-${string}-${string}`,
+        priority: (userMsg as { priority?: string }).priority as import('src/types/textInputTypes.js').QueuePriority,
       })
       // Increment prompt count for attribution tracking and save snapshot
       // The snapshot persists promptCount so it survives compaction
@@ -4463,7 +4477,7 @@ async function handleInitializeRequest(
     })),
     output_style: outputStyle,
     available_output_styles: Object.keys(availableOutputStyles),
-    models: modelInfos,
+    models: modelInfos as unknown as SDKControlInitializeResponse['models'],
     account: {
       email: accountInfo?.email,
       organization: accountInfo?.organization,
@@ -4473,7 +4487,7 @@ async function handleInitializeRequest(
       // getAccountInformation() returns undefined under 3P providers, so the
       // other fields are all absent. apiProvider disambiguates "not logged
       // in" (firstParty + tokenSource:none) from "3P, login not applicable".
-      apiProvider: getAPIProvider(),
+      apiProvider: getAPIProvider() as 'firstParty' | 'bedrock' | 'vertex' | 'foundry',
     },
     pid: process.pid,
   }
diff --git a/src/cli/structuredIO.ts b/src/cli/structuredIO.ts
index d5cedfa2d..3f8d426e2 100644
--- a/src/cli/structuredIO.ts
+++ b/src/cli/structuredIO.ts
@@ -355,7 +355,7 @@ export class StructuredIO {
         // Used by bridge session runner for auth token refresh
         // (CLAUDE_CODE_SESSION_ACCESS_TOKEN) which must be readable
         // by the REPL process itself, not just child Bash commands.
-        const variables = message.variables as Record<string, string>
+        const variables = message.variables ?? {}
         const keys = Object.keys(variables)
         for (const [key, value] of Object.entries(variables)) {
           process.env[key] = value
@@ -377,7 +377,8 @@ export class StructuredIO {
         if (uuid) {
           notifyCommandLifecycle(uuid, 'completed')
         }
-        const request = this.pendingRequests.get(message.response.request_id)
+        const resp = message.response as { request_id: string; subtype: string; response?: Record<string, unknown>; error?: string }
+        const request = this.pendingRequests.get(resp.request_id)
         if (!request) {
           // Check if this tool_use was already resolved through the normal
           // permission flow. Duplicate control_response deliveries (e.g. from
@@ -385,8 +386,8 @@ export class StructuredIO {
           // re-processing them would push duplicate assistant messages into
           // the conversation, causing API 400 errors.
           const responsePayload =
-            message.response.subtype === 'success'
-              ? message.response.response
+            resp.subtype === 'success'
+              ? resp.response
               : undefined
           const toolUseID = responsePayload?.toolUseID
           if (
@@ -394,31 +395,31 @@ export class StructuredIO {
             this.resolvedToolUseIds.has(toolUseID)
           ) {
             logForDebugging(
-              `Ignoring duplicate control_response for already-resolved toolUseID=${toolUseID} request_id=${message.response.request_id}`,
+              `Ignoring duplicate control_response for already-resolved toolUseID=${toolUseID} request_id=${resp.request_id}`,
             )
             return undefined
           }
           if (this.unexpectedResponseCallback) {
-            await this.unexpectedResponseCallback(message)
+            await this.unexpectedResponseCallback(message as SDKControlResponse & { uuid?: string })
           }
           return undefined // Ignore responses for requests we don't know about
         }
         this.trackResolvedToolUseId(request.request)
-        this.pendingRequests.delete(message.response.request_id)
+        this.pendingRequests.delete(resp.request_id)
         // Notify the bridge when the SDK consumer resolves a can_use_tool
         // request, so it can cancel the stale permission prompt on claude.ai.
         if (
           (request.request.request as { subtype?: string }).subtype === 'can_use_tool' &&
           this.onControlRequestResolved
         ) {
-          this.onControlRequestResolved(message.response.request_id)
+          this.onControlRequestResolved(resp.request_id)
         }
 
-        if (message.response.subtype === 'error') {
-          request.reject(new Error(message.response.error))
+        if (resp.subtype === 'error') {
+          request.reject(new Error(resp.error ?? 'Unknown error'))
           return undefined
         }
-        const result = message.response.response
+        const result = resp.response
         if (request.schema) {
           try {
             request.resolve(request.schema.parse(result))
@@ -454,9 +455,9 @@ export class StructuredIO {
       if (message.type === 'assistant' || message.type === 'system') {
         return message
       }
-      if (message.message.role !== 'user') {
+      if ((message as { message?: { role?: string } }).message?.role !== 'user') {
         exitWithMessage(
-          `Error: Expected message role 'user', got '${message.message.role}'`,
+          `Error: Expected message role 'user', got '${(message as { message?: { role?: string } }).message?.role}'`,
         )
       }
       return message
@@ -678,7 +679,7 @@ export class StructuredIO {
             {
               subtype: 'hook_callback',
               callback_id: callbackId,
-              input,
+              input: input as Parameters<HookCallback['callback']>[0],
               tool_use_id: toolUseID || undefined,
             },
             hookJSONOutputSchema(),
diff --git a/src/commands/remoteControlServer/remoteControlServer.tsx b/src/commands/remoteControlServer/remoteControlServer.tsx
index 0d350a7a0..dc08a9cbc 100644
--- a/src/commands/remoteControlServer/remoteControlServer.tsx
+++ b/src/commands/remoteControlServer/remoteControlServer.tsx
@@ -148,7 +148,7 @@ function ServerManagementDialog({ onDone }: Props): React.ReactNode {
       <Box flexDirection="column" gap={1}>
         <Text>
           Remote Control Server is{' '}
-          <Text bold color="green">
+          <Text bold color="success">
             running
           </Text>
           {daemonProcess ? ` (PID: ${daemonProcess.pid})` : ''}
@@ -233,10 +233,10 @@ function startDaemon(): void {
     }
   });
 
-  child.on('exit', (code, signal) => {
+  child.on('exit', (code: number | null, signal: NodeJS.Signals | null) => {
     daemonProcess = null;
     daemonStatus = 'stopped';
-    daemonLogs.push(`[daemon] exited (code=${code}, signal=${signal})`);
+    daemonLogs.push(`[daemon] exited (code=${code ?? 'unknown'}, signal=${signal})`);
   });
 
   child.on('error', (err: Error) => {
diff --git a/src/components/BuiltinStatusLine.tsx b/src/components/BuiltinStatusLine.tsx
index fdbf2969d..45fe3805b 100644
--- a/src/components/BuiltinStatusLine.tsx
+++ b/src/components/BuiltinStatusLine.tsx
@@ -55,7 +55,7 @@ function BuiltinStatusLineInner({
   // Force re-render every 60s so countdowns stay current
   const [tick, setTick] = useState(0);
   useEffect(() => {
-    const hasResetTime = rateLimits.five_hour?.resets_at || rateLimits.seven_day?.resets_at;
+    const hasResetTime = (rateLimits.five_hour?.resets_at ?? 0) || (rateLimits.seven_day?.resets_at ?? 0);
     if (!hasResetTime) return;
     const id = setInterval(() => setTick(t => t + 1), 60_000);
     return () => clearInterval(id);
diff --git a/src/components/CompactSummary.tsx b/src/components/CompactSummary.tsx
index e343a6591..5d582a299 100644
--- a/src/components/CompactSummary.tsx
+++ b/src/components/CompactSummary.tsx
@@ -15,7 +15,11 @@ type Props = {
 export function CompactSummary({ message, screen }: Props): React.ReactNode {
   const isTranscriptMode = screen === 'transcript'
   const textContent = getUserMessageText(message) || ''
-  const metadata = message.summarizeMetadata
+  const metadata = message.summarizeMetadata as {
+    messagesSummarized?: number
+    direction?: string
+    userContext?: string
+  } | undefined
 
   // "Summarize from here" with metadata
   if (metadata) {
diff --git a/src/components/PromptInput/PromptInputFooterSuggestions.tsx b/src/components/PromptInput/PromptInputFooterSuggestions.tsx
index 689123581..60dc39d57 100644
--- a/src/components/PromptInput/PromptInputFooterSuggestions.tsx
+++ b/src/components/PromptInput/PromptInputFooterSuggestions.tsx
@@ -163,7 +163,7 @@ const SuggestionItemRow = memo(function SuggestionItemRow({
         {paddedDisplayText}
       </Text>
       {tagText ? (
-        <Text color={item.tag === 'local' ? 'yellow' : undefined} dimColor={item.tag !== 'local'}>
+        <Text color={item.tag === 'local' ? ('yellow' as const) : undefined} dimColor={item.tag !== 'local'}>
           {tagText}
         </Text>
       ) : null}
diff --git a/src/components/skills/SkillsMenu.tsx b/src/components/skills/SkillsMenu.tsx
index 4b33eee57..37a196d45 100644
--- a/src/components/skills/SkillsMenu.tsx
+++ b/src/components/skills/SkillsMenu.tsx
@@ -162,13 +162,13 @@ export function SkillsMenu({ onExit, commands }: Props): React.ReactNode {
       skill.source === 'plugin'
         ? skill.pluginInfo?.pluginManifest.name
         : undefined
-    const scopeTag = getScopeTag(skill.source as SkillSource)
+    const scopeTag = getScopeTag(skill.source)
 
     return (
       <Box key={`${skill.name}-${skill.source}`}>
         <Text>{getCommandName(skill)}</Text>
         {scopeTag && (
-          <Text color={scopeTag.color}> [{scopeTag.label}]</Text>
+          <Text color={scopeTag.color as keyof Theme}> [{scopeTag.label}]</Text>
         )}
         <Text dimColor>
           {pluginName ? ` · ${pluginName}` : ''} · {tokenDisplay} description
diff --git a/src/components/tasks/RemoteSessionDetailDialog.tsx b/src/components/tasks/RemoteSessionDetailDialog.tsx
index ec2c43b42..1e2e2e46c 100644
--- a/src/components/tasks/RemoteSessionDetailDialog.tsx
+++ b/src/components/tasks/RemoteSessionDetailDialog.tsx
@@ -122,7 +122,8 @@ function UltraplanSessionDetail({
     let lastBlock: { name: string; input: unknown } | null = null
     for (const msg of session.log) {
       if (msg.type !== 'assistant') continue
-      for (const block of msg.message.content) {
+      const content = msg.message?.content ?? []
+      for (const block of content as Array<{type: string; name: string; input: unknown}>) {
         if (block.type !== 'tool_use') continue
         calls++
         lastBlock = block
diff --git a/src/hooks/useReplBridge.tsx b/src/hooks/useReplBridge.tsx
index 7be394869..c19304ffe 100644
--- a/src/hooks/useReplBridge.tsx
+++ b/src/hooks/useReplBridge.tsx
@@ -225,13 +225,16 @@ export function useReplBridge(
               const { resolveAndPrepend } = await import(
                 '../bridge/inboundAttachments.js'
               )
-              let sanitized = fields.content
+              const rawContent = fields.content
+              let sanitized: string | Array<{ type: string; [key: string]: unknown }> = typeof rawContent === 'string' ? rawContent : rawContent as Array<{ type: string; [key: string]: unknown }>
               if (feature('KAIROS_GITHUB_WEBHOOKS')) {
                 /* eslint-disable @typescript-eslint/no-require-imports */
                 const { sanitizeInboundWebhookContent } =
                   require('../bridge/webhookSanitizer.js') as typeof import('../bridge/webhookSanitizer.js')
                 /* eslint-enable @typescript-eslint/no-require-imports */
-                sanitized = sanitizeInboundWebhookContent(fields.content)
+                if (typeof sanitized === 'string') {
+                  sanitized = sanitizeInboundWebhookContent(sanitized)
+                }
               }
               const content = await resolveAndPrepend(msg, sanitized)
 
diff --git a/src/services/api/gemini/index.ts b/src/services/api/gemini/index.ts
index 64dff7458..6935ac1bc 100644
--- a/src/services/api/gemini/index.ts
+++ b/src/services/api/gemini/index.ts
@@ -56,7 +56,7 @@ export async function* queryModelGemini(
 
     const standardTools = toolSchemas.filter(
       (t): t is BetaToolUnion & { type: string } => {
-        const anyTool = t as Record<string, unknown>
+        const anyTool = t as unknown as Record<string, unknown>
         return (
           anyTool.type !== 'advisor_20260301' &&
           anyTool.type !== 'computer_20250124'
@@ -186,7 +186,7 @@ export async function* queryModelGemini(
     yield createAssistantAPIErrorMessage({
       content: `API Error: ${errorMessage}`,
       apiError: 'api_error',
-      error: error instanceof Error ? error : new Error(String(error)),
+      error: (error instanceof Error ? error : new Error(String(error))) as Error,
     })
   }
 }
diff --git a/src/services/api/grok/index.ts b/src/services/api/grok/index.ts
index d8b429ded..8e4f934b4 100644
--- a/src/services/api/grok/index.ts
+++ b/src/services/api/grok/index.ts
@@ -2,6 +2,10 @@ import type { BetaToolUnion } from '@anthropic-ai/sdk/resources/beta/messages/me
 import type { SystemPrompt } from '../../../utils/systemPromptType.js'
 import type { Message, StreamEvent, SystemAPIErrorMessage, AssistantMessage } from '../../../types/message.js'
 import type { Tools } from '../../../Tool.js'
+import type {
+  ChatCompletionChunk,
+  ChatCompletionCreateParamsStreaming,
+} from 'openai/resources/chat/completions/completions.mjs'
 import { getGrokClient } from './client.js'
 import { anthropicMessagesToOpenAI } from '../openai/convertMessages.js'
 import { anthropicToolsToOpenAI, anthropicToolChoiceToOpenAI } from '../openai/convertTools.js'
@@ -51,7 +55,7 @@ export async function* queryModelGrok(
     )
     const standardTools = toolSchemas.filter(
       (t): t is BetaToolUnion & { type: string } => {
-        const anyT = t as Record<string, unknown>
+        const anyT = t as unknown as Record<string, unknown>
         return anyT.type !== 'advisor_20260301' && anyT.type !== 'computer_20250124'
       },
     )
@@ -62,7 +66,7 @@ export async function* queryModelGrok(
 
     const client = getGrokClient({
       maxRetries: 0,
-      fetchOverride: options.fetchOverride,
+      fetchOverride: options.fetchOverride as typeof fetch | undefined,
       source: options.querySource,
     })
 
@@ -81,13 +85,13 @@ export async function* queryModelGrok(
         ...(options.temperatureOverride !== undefined && {
           temperature: options.temperatureOverride,
         }),
-      },
+      } as ChatCompletionCreateParamsStreaming,
       {
         signal,
       },
     )
 
-    const adaptedStream = adaptOpenAIStreamToAnthropic(stream, grokModel)
+    const adaptedStream = adaptOpenAIStreamToAnthropic(stream as AsyncIterable<ChatCompletionChunk>, grokModel)
 
     const contentBlocks: Record<number, any> = {}
     let partialMessage: any = undefined
@@ -186,7 +190,7 @@ export async function* queryModelGrok(
     yield createAssistantAPIErrorMessage({
       content: `API Error: ${errorMessage}`,
       apiError: 'api_error',
-      error: error instanceof Error ? error : new Error(String(error)),
+      error: (error instanceof Error ? error : new Error(String(error))) as Error,
     })
   }
 }
diff --git a/src/services/api/openai/client.ts b/src/services/api/openai/client.ts
index 111e8a330..eea96cb8e 100644
--- a/src/services/api/openai/client.ts
+++ b/src/services/api/openai/client.ts
@@ -1,6 +1,6 @@
 import OpenAI from 'openai'
 import { getProxyFetchOptions } from 'src/utils/proxy.js'
-import { isEnvTruthy } from '../../utils/envUtils.js'
+import { isEnvTruthy } from 'src/utils/envUtils.js'
 
 /**
  * Environment variables:
diff --git a/src/services/api/openai/index.ts b/src/services/api/openai/index.ts
index 958f0b3d4..0f350ad3e 100644
--- a/src/services/api/openai/index.ts
+++ b/src/services/api/openai/index.ts
@@ -7,6 +7,11 @@ import type {
   AssistantMessage,
 } from '../../../types/message.js'
 import type { Tools } from '../../../Tool.js'
+import type { Stream } from 'openai/streaming.mjs'
+import type {
+  ChatCompletionChunk,
+  ChatCompletionCreateParamsStreaming,
+} from 'openai/resources/chat/completions/completions.mjs'
 import { getOpenAIClient } from './client.js'
 import { anthropicMessagesToOpenAI } from './convertMessages.js'
 import {
@@ -82,7 +87,7 @@ export function buildOpenAIRequestBody(params: {
   toolChoice: any
   enableThinking: boolean
   temperatureOverride?: number
-}): Record<string, any> {
+}): ChatCompletionCreateParamsStreaming {
   const { model, messages, tools, toolChoice, enableThinking, temperatureOverride } = params
   return {
     model,
@@ -183,7 +188,7 @@ export async function* queryModelOpenAI(
     // 7. Filter out non-standard tools (server tools like advisor)
     const standardTools = toolSchemas.filter(
       (t): t is BetaToolUnion & { type: string } => {
-        const anyT = t as Record<string, unknown>
+        const anyT = t as unknown as Record<string, unknown>
         return (
           anyT.type !== 'advisor_20260301' && anyT.type !== 'computer_20250124'
         )
@@ -349,7 +354,7 @@ export async function* queryModelOpenAI(
     yield createAssistantAPIErrorMessage({
       content: `API Error: ${errorMessage}`,
       apiError: 'api_error',
-      error: error instanceof Error ? error : new Error(String(error)),
+      error: (error instanceof Error ? error : new Error(String(error))) as Error,
     })
   }
 }
\ No newline at end of file
diff --git a/src/tools/AgentTool/UI.tsx b/src/tools/AgentTool/UI.tsx
index b6bc20da4..f1e762f57 100644
--- a/src/tools/AgentTool/UI.tsx
+++ b/src/tools/AgentTool/UI.tsx
@@ -125,7 +125,7 @@ function processProgressMessages(
   isAgentRunning: boolean,
 ): ProcessedMessage[] {
   // Only process for ants
-  if ("external" !== 'ant') {
+  if (process.env.USER_TYPE !== 'ant') {
     return messages
       .filter(
         (m): m is ProgressMessage<AgentToolProgress> =>
@@ -411,7 +411,7 @@ export function renderToolResultMessage(
 
   const finalAssistantMessage = createAssistantMessage({
     content: completionMessage,
-    usage: { ...usage, inference_geo: null, iterations: null, speed: null },
+    usage: { ...usage, inference_geo: null, iterations: null, speed: null } as typeof usage,
   })
 
   return (
@@ -866,7 +866,7 @@ export function renderGroupedAgentToolUse(
         taskDescription = parsedInput.data.description
         // Use the custom agent definition's color on the type, not the name
         descriptionColor = isCustomSubagentType(subagentType)
-          ? (getAgentColor(subagentType) as keyof Theme | undefined)
+          ? getAgentColor(subagentType)
           : undefined
       } else {
         agentType = parsedInput.success
@@ -1019,7 +1019,7 @@ export function userFacingNameBackgroundColor(
   }
 
   // Get the color for this agent
-  return getAgentColor(input.subagent_type) as keyof Theme | undefined
+  return getAgentColor(input.subagent_type)
 }
 
 export function extractLastToolInfo(
diff --git a/src/utils/computerUse/executor.ts b/src/utils/computerUse/executor.ts
index 346ac7d50..1c5ba247d 100644
--- a/src/utils/computerUse/executor.ts
+++ b/src/utils/computerUse/executor.ts
@@ -423,18 +423,21 @@ export function createCliExecutor(opts: {
           targetW,
           targetH,
           opts.preferredDisplayId,
-          opts.autoResolve,
-          opts.doHide,
         ),
       )
       // Ensure the result has fields expected by toolCalls.ts (hidden, displayId).
       // macOS native returns these from Swift; our cross-platform ComputerUseAPI
       // returns {base64, width, height} — fill in the missing fields.
+      const baseResult = raw as Partial<ResolvePrepareCaptureResult> & { width?: number; height?: number }
       return {
         ...raw,
-        hidden: (raw as any).hidden ?? [],
-        displayId: (raw as any).displayId ?? opts.preferredDisplayId ?? d.displayId,
-      }
+        displayWidth: baseResult.displayWidth ?? baseResult.width,
+        displayHeight: baseResult.displayHeight ?? baseResult.height,
+        originX: baseResult.originX ?? 0,
+        originY: baseResult.originY ?? 0,
+        hidden: baseResult.hidden ?? [],
+        displayId: baseResult.displayId ?? opts.preferredDisplayId ?? d.displayId,
+      } as ResolvePrepareCaptureResult
     },
 
     /**
diff --git a/src/utils/computerUse/win32/bridgeClient.ts b/src/utils/computerUse/win32/bridgeClient.ts
index b3f8a3749..70e747f5e 100644
--- a/src/utils/computerUse/win32/bridgeClient.ts
+++ b/src/utils/computerUse/win32/bridgeClient.ts
@@ -9,6 +9,7 @@
  */
 
 import * as path from 'path'
+import type { Writable } from 'stream'
 
 interface BridgeRequest {
   id: number
@@ -48,7 +49,7 @@ export function ensureBridge(): boolean {
     })
 
     // Read stdout lines asynchronously
-    const reader = bridgeProc.stdout.getReader()
+    const reader = (bridgeProc.stdout as ReadableStream<Uint8Array>).getReader()
     const readLoop = async () => {
       try {
         while (true) {
@@ -114,12 +115,12 @@ export async function call<T = unknown>(
     }, timeoutMs)
 
     // Clear timeout on resolve/reject
-    const origResolve = resolve
+    const origResolve = resolve as (v: unknown) => void
     const origReject = reject
     pendingRequests.set(id, {
       resolve: v => {
         clearTimeout(timer)
-        ;(origResolve as any)(v)
+        origResolve(v)
       },
       reject: e => {
         clearTimeout(timer)
@@ -128,8 +129,14 @@ export async function call<T = unknown>(
     })
 
     try {
-      bridgeProc!.stdin.write(JSON.stringify(req) + '\n')
-      bridgeProc!.stdin.flush()
+      const stdin = bridgeProc!.stdin
+      if (stdin) {
+        const writable = stdin as Writable
+        writable.write(JSON.stringify(req) + '\n')
+        if (typeof writable.flush === 'function') {
+          writable.flush()
+        }
+      }
     } catch (err) {
       clearTimeout(timer)
       pendingRequests.delete(id)
@@ -176,7 +183,13 @@ export function callSync<T = unknown>(
 export function stopBridge(): void {
   if (bridgeProc) {
     try {
-      bridgeProc.stdin.end()
+      const stdin = bridgeProc.stdin
+      if (stdin) {
+        const writable = stdin as Writable
+        if (typeof writable.end === 'function') {
+          writable.end()
+        }
+      }
       bridgeProc.kill()
     } catch {}
     bridgeProc = null
diff --git a/src/utils/streamlinedTransform.ts b/src/utils/streamlinedTransform.ts
index 8b7aa4430..36245c389 100644
--- a/src/utils/streamlinedTransform.ts
+++ b/src/utils/streamlinedTransform.ts
@@ -137,13 +137,14 @@ export function createStreamlinedTransformer(): (
   ): StdoutMessage | null {
     switch (message.type) {
       case 'assistant': {
-        const content = message.message.content
+        const messageContent = (message as SDKAssistantMessage).message
+        const content = messageContent?.content
         const text = Array.isArray(content)
           ? extractTextContent(content, '\n').trim()
           : ''
 
         // Accumulate tool counts from this message
-        accumulateToolUses(message, cumulativeCounts)
+        accumulateToolUses(message as SDKAssistantMessage, cumulativeCounts)
 
         if (text.length > 0) {
           // Text message: emit text only, reset counts