diff --git a/src/main/apiServer/routes/agents/handlers/messages.ts b/src/main/apiServer/routes/agents/handlers/messages.ts
index 1b547abba8..abec51ec01 100644
--- a/src/main/apiServer/routes/agents/handlers/messages.ts
+++ b/src/main/apiServer/routes/agents/handlers/messages.ts
@@ -1,6 +1,10 @@
 import { loggerService } from '@logger'
 import { MESSAGE_STREAM_TIMEOUT_MS } from '@main/apiServer/config/timeouts'
-import { createStreamAbortController, STREAM_TIMEOUT_REASON } from '@main/apiServer/utils/createStreamAbortController'
+import {
+  createStreamAbortController,
+  STREAM_TIMEOUT_REASON,
+  type StreamAbortController
+} from '@main/apiServer/utils/createStreamAbortController'
 import { agentService, sessionMessageService, sessionService } from '@main/services/agents'
 import type { Request, Response } from 'express'
 
@@ -26,7 +30,7 @@ const verifyAgentAndSession = async (agentId: string, sessionId: string) => {
 }
 
 export const createMessage = async (req: Request, res: Response): Promise<void> => {
-  let clearAbortTimeout: (() => void) | undefined
+  let streamController: StreamAbortController | undefined
 
   try {
     const { agentId, sessionId } = req.params
@@ -45,14 +49,10 @@ export const createMessage = async (req: Request, res: Response): Promise<void>
     res.setHeader('Access-Control-Allow-Origin', '*')
     res.setHeader('Access-Control-Allow-Headers', 'Cache-Control')
 
-    const {
-      abortController,
-      registerAbortHandler,
-      clearAbortTimeout: helperClearAbortTimeout
-    } = createStreamAbortController({
+    streamController = createStreamAbortController({
       timeoutMs: MESSAGE_STREAM_TIMEOUT_MS
     })
-    clearAbortTimeout = helperClearAbortTimeout
+    const { abortController, registerAbortHandler, dispose } = streamController
     const { stream, completion } = await sessionMessageService.createSessionMessage(
       session,
       messageData,
@@ -64,8 +64,8 @@ export const createMessage = async (req: Request, res: Response): Promise<void>
     let responseEnded = false
     let streamFinished = false
 
-    const cleanupAbortTimeout = () => {
-      clearAbortTimeout?.()
+    const cleanup = () => {
+      dispose()
     }
 
     const finalizeResponse = () => {
@@ -78,7 +78,7 @@ export const createMessage = async (req: Request, res: Response): Promise<void>
       }
 
       responseEnded = true
-      cleanupAbortTimeout()
+      cleanup()
       try {
         // res.write('data: {"type":"finish"}\n\n')
         res.write('data: [DONE]\n\n')
@@ -108,7 +108,7 @@ export const createMessage = async (req: Request, res: Response): Promise<void>
      * - Mark the response as ended to prevent further writes
      */
     registerAbortHandler((abortReason) => {
-      cleanupAbortTimeout()
+      cleanup()
 
       if (responseEnded) return
 
@@ -189,7 +189,7 @@ export const createMessage = async (req: Request, res: Response): Promise<void>
           logger.error('Error writing stream error to SSE', { error: writeError })
         }
         responseEnded = true
-        cleanupAbortTimeout()
+        cleanup()
         res.end()
       }
     }
@@ -221,14 +221,14 @@ export const createMessage = async (req: Request, res: Response): Promise<void>
           logger.error('Error writing completion error to SSE stream', { error: writeError })
         }
         responseEnded = true
-        cleanupAbortTimeout()
+        cleanup()
         res.end()
       })
     // Clear timeout when response ends
-    res.on('close', cleanupAbortTimeout)
-    res.on('finish', cleanupAbortTimeout)
+    res.on('close', cleanup)
+    res.on('finish', cleanup)
   } catch (error: any) {
-    clearAbortTimeout?.()
+    streamController?.dispose()
     logger.error('Error in streaming message handler', {
       error,
       agentId: req.params.agentId,
diff --git a/src/main/apiServer/utils/createStreamAbortController.ts b/src/main/apiServer/utils/createStreamAbortController.ts
index 243ad5b96e..e07b9a31f0 100644
--- a/src/main/apiServer/utils/createStreamAbortController.ts
+++ b/src/main/apiServer/utils/createStreamAbortController.ts
@@ -4,6 +4,7 @@ export interface StreamAbortController {
   abortController: AbortController
   registerAbortHandler: (handler: StreamAbortHandler) => void
   clearAbortTimeout: () => void
+  dispose: () => void
 }
 
 export const STREAM_TIMEOUT_REASON = 'stream timeout'
@@ -40,6 +41,15 @@ export const createStreamAbortController = (options: CreateStreamAbortController
 
   signal.addEventListener('abort', handleAbort, { once: true })
 
+  let disposed = false
+
+  const dispose = () => {
+    if (disposed) return
+    disposed = true
+    clearAbortTimeout()
+    signal.removeEventListener('abort', handleAbort)
+  }
+
   const registerAbortHandler = (handler: StreamAbortHandler) => {
     abortHandler = handler
 
@@ -59,6 +69,7 @@ export const createStreamAbortController = (options: CreateStreamAbortController
   return {
     abortController,
     registerAbortHandler,
-    clearAbortTimeout
+    clearAbortTimeout,
+    dispose
   }
 }