show chat run errors as agent messages (#887)

packages/client/src/api/hermes/chat.ts

@@ -467,6 +467,18 @@ export function disconnectChatRun(): void {
   }
 }
 
+function removeSocketListener(socket: Socket, event: string, handler: (...args: any[]) => void): void {
+  const candidate = socket as Socket & {
+    off?: (event: string, handler: (...args: any[]) => void) => Socket
+    removeListener?: (event: string, handler: (...args: any[]) => void) => Socket
+  }
+  if (typeof candidate.off === 'function') {
+    candidate.off(event, handler)
+    return
+  }
+  candidate.removeListener?.(event, handler)
+}
+
 /**
  * Start a chat run via Socket.IO and stream events back.
  * Returns an AbortController-compatible handle for cancellation.
@@ -500,6 +512,23 @@ export function startRunViaSocket(
 
   let closed = false
   const socket = connectChatRun()
+  const handleSocketError = (err: Error) => {
+    if (closed) return
+    closed = true
+    sessionEventHandlers.delete(sid)
+    onError(err)
+  }
+  socket.once('connect_error', handleSocketError)
+  const handleSocketDisconnect = (reason: string) => {
+    if (closed || reason === 'io client disconnect') return
+    handleSocketError(new Error(`Socket disconnected: ${reason}`))
+  }
+  socket.once('disconnect', handleSocketDisconnect)
+
+  const removeTerminalSocketListeners = () => {
+    removeSocketListener(socket, 'connect_error', handleSocketError)
+    removeSocketListener(socket, 'disconnect', handleSocketDisconnect)
+  }
 
   if (sessionEventHandlers.has(sid)) {
     socket.emit('run', body)
@@ -548,6 +577,7 @@ export function startRunViaSocket(
       onEvent(evt)
       if ((evt as any).queue_remaining > 0) return
       closed = true
+      removeTerminalSocketListeners()
       onDone()
     },
     onRunFailed: (evt: RunEvent) => {
@@ -555,7 +585,8 @@ export function startRunViaSocket(
       onEvent(evt)
       if ((evt as any).queue_remaining > 0) return
       closed = true
-      onError(new Error(evt.error || 'Run failed'))
+      removeTerminalSocketListeners()
+      onDone()
     },
     onCompressionStarted: (evt: RunEvent) => {
       if (closed) return
@@ -574,6 +605,7 @@ export function startRunViaSocket(
       onEvent(evt)
       if ((evt as any).queue_length > 0) return
       closed = true
+      removeTerminalSocketListeners()
       onDone()
     },
     onUsageUpdated: (evt: RunEvent) => {
@@ -585,6 +617,7 @@ export function startRunViaSocket(
       onEvent(evt)
       if ((evt as any).terminal === false) return
       closed = true
+      removeTerminalSocketListeners()
       sessionEventHandlers.delete(sid)
       onDone()
     },

packages/client/src/api/hermes/group-chat.ts

@@ -34,7 +34,7 @@ export interface ChatMessage {
     tool_call_id?: string | null
     tool_calls?: any[] | null
     tool_name?: string | null
-    finish_reason?: string | null
+    finish_reason?: 'streaming' | 'tool_calls' | 'error' | string | null
     reasoning?: string | null
     reasoning_details?: string | null
     reasoning_content?: string | null