From a257f45248a64f7e1a2c88cbec33c2e399456efe Mon Sep 17 00:00:00 2001
From: Chris0Jeky <jeky.tck@gmail.com>
Date: Wed, 9 Sep 2026 21:07:14 +0100
Subject: [PATCH] Fail fast when reconciling a successful chat send

---
 frontend/taskdeck-web/src/api/chatApi.ts                  | 4 ++--
 .../taskdeck-web/src/composables/useAutomationChat.ts     | 4 +++-
 frontend/taskdeck-web/src/tests/api/chatApi.spec.ts       | 8 ++++++++
 .../src/tests/composables/useAutomationChat.spec.ts       | 3 +++
 .../src/tests/store/chatApi.integration.spec.ts           | 4 ++--
 5 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/frontend/taskdeck-web/src/api/chatApi.ts b/frontend/taskdeck-web/src/api/chatApi.ts
index f8399b387b..0639acaa39 100644
--- a/frontend/taskdeck-web/src/api/chatApi.ts
+++ b/frontend/taskdeck-web/src/api/chatApi.ts
@@ -13,8 +13,8 @@ export const chatApi = {
     return data
   },
 
-  async getSession(sessionId: string): Promise<ChatSession> {
-    const { data } = await http.get<ChatSession>(`/llm/chat/sessions/${encodeURIComponent(sessionId)}`)
+  async getSession(sessionId: string, options?: { skipRetry?: boolean }): Promise<ChatSession> {
+    const { data } = await http.get<ChatSession>(`/llm/chat/sessions/${encodeURIComponent(sessionId)}`, options)
     return data
   },
 
diff --git a/frontend/taskdeck-web/src/composables/useAutomationChat.ts b/frontend/taskdeck-web/src/composables/useAutomationChat.ts
index e597622081..eb9dacc822 100644
--- a/frontend/taskdeck-web/src/composables/useAutomationChat.ts
+++ b/frontend/taskdeck-web/src/composables/useAutomationChat.ts
@@ -284,7 +284,9 @@ export function useAutomationChat() {
 
   async function refreshSelectedSession(sessionId: string) {
     try {
-      const result = await chatApi.getSession(sessionId)
+      // The send already succeeded and its messages are retained locally. A
+      // failed reconciliation must not hold continuation behind read retries.
+      const result = await chatApi.getSession(sessionId, { skipRetry: true })
       if (isDisposed || requestedSessionId !== sessionId || selectedSession.value?.id !== sessionId) return
       localMessagesBySession.delete(sessionId)
       sessionWriteGenerations.set(sessionId, (sessionWriteGenerations.get(sessionId) ?? 0) + 1)
diff --git a/frontend/taskdeck-web/src/tests/api/chatApi.spec.ts b/frontend/taskdeck-web/src/tests/api/chatApi.spec.ts
index 5343934545..e19556b4c5 100644
--- a/frontend/taskdeck-web/src/tests/api/chatApi.spec.ts
+++ b/frontend/taskdeck-web/src/tests/api/chatApi.spec.ts
@@ -43,6 +43,14 @@ describe('chatApi', () => {
     })
   })
 
+  it('can fail fast for a post-send reconciliation read', async () => {
+    const failure = new Error('Refresh unavailable')
+    vi.mocked(http.get).mockRejectedValue(failure)
+
+    await expect(chatApi.getSession('session/1', { skipRetry: true })).rejects.toBe(failure)
+    expect(http.get).toHaveBeenCalledWith('/llm/chat/sessions/session%2F1', { skipRetry: true })
+  })
+
   it('loads provider health', async () => {
     const healthPayload = {
       isAvailable: true,
diff --git a/frontend/taskdeck-web/src/tests/composables/useAutomationChat.spec.ts b/frontend/taskdeck-web/src/tests/composables/useAutomationChat.spec.ts
index 0dd1fe9a3e..32dc75da46 100644
--- a/frontend/taskdeck-web/src/tests/composables/useAutomationChat.spec.ts
+++ b/frontend/taskdeck-web/src/tests/composables/useAutomationChat.spec.ts
@@ -544,6 +544,9 @@ describe('useAutomationChat', () => {
       chat.messageContent.value = 'new instruction'
       await chat.handleSendMessage()
 
+      expect(chatApiMocks.getSession).toHaveBeenNthCalledWith(1, 's1')
+      expect(chatApiMocks.getSession).toHaveBeenLastCalledWith('s1', { skipRetry: true })
+      expect(chat.sendingMessage.value).toBe(false)
       expect(chat.selectedSession.value?.recentMessages.map((message) => message.content)).toEqual([
         'older instruction',
         'No board linked',
diff --git a/frontend/taskdeck-web/src/tests/store/chatApi.integration.spec.ts b/frontend/taskdeck-web/src/tests/store/chatApi.integration.spec.ts
index 0f2713a9b9..b433f297f9 100644
--- a/frontend/taskdeck-web/src/tests/store/chatApi.integration.spec.ts
+++ b/frontend/taskdeck-web/src/tests/store/chatApi.integration.spec.ts
@@ -158,7 +158,7 @@ describe('chatApi — integration (mocked HTTP)', () => {
       expect(result.recentMessages).toHaveLength(2)
       expect(result.recentMessages[0].role).toBe('User')
       expect(result.recentMessages[1].role).toBe('Assistant')
-      expect(http.get).toHaveBeenCalledWith('/llm/chat/sessions/session-1')
+      expect(http.get).toHaveBeenCalledWith('/llm/chat/sessions/session-1', undefined)
     })
 
     it('URL-encodes special characters in the session ID', async () => {
@@ -166,7 +166,7 @@ describe('chatApi — integration (mocked HTTP)', () => {
 
       await chatApi.getSession('session/special')
 
-      expect(http.get).toHaveBeenCalledWith('/llm/chat/sessions/session%2Fspecial')
+      expect(http.get).toHaveBeenCalledWith('/llm/chat/sessions/session%2Fspecial', undefined)
     })
 
     it('propagates 404 when session does not exist', async () => {