[Bug] ZCode 3.10.1 WeChat Bot: Replies Generated but... | zai-org/feedback

Bug Description

WeChat bot in ZCode 3.10.1 receives and processes messages correctly, but generated replies are never delivered back to WeChat. The failure is completely silent — no error messages, no log entries for the send attempt, and no visible indication of failure to the user.

Impact Severity: HIGH — Core Bot Functionality Broken

WeChat bot is completely non-functional for outbound communication
Users see "typing…" indicator then nothing arrives
No error feedback makes debugging extremely difficult
Affects all WeChat bot users on ZCode 3.10.1

Detailed Report

Environment

Component	Value
ZCode Version	3.10.1
Platform	Linux AppImage
OS	Ubuntu 26.04
Plan	GLM Coding Plan (GLM-5.3)
Bot Type	WeChat bot
Connection Mode	Long-polling
Reply Mode	Standard

Reproduction Steps

Bind WeChat via QR code → Succeeds, status shows "long-polling running"
Send any text message from WeChat to the bot
Observe behavior:
- WeChat shows "typing…" indicator for a few seconds
- Then nothing — no reply ever arrives
Check ZCode desktop:
- Message was received ✅
- Task was created in bound workspace ✅
- Agent reply was generated (status: completed) ✅
- Reply was NOT delivered to WeChat ❌
Test bot commands: /status and other commands also get no reply

Expected Behavior

Reply should be delivered back to WeChat after agent completes
User should see the response in their WeChat chat window
If delivery fails, there should be a visible error in logs or UI
All bot commands should receive responses

Actual Behavior

User Experience (WeChat Side):

User sends: "测试" (test)
    ↓
Bot shows: "typing..." (3-5 seconds)
    ↓
Result: [EMPTY] — nothing arrives, no error, no failure message

System Behavior (ZCode Side):

✅ Step 1: Message RECEIVED
   Log: 00:54:39 [bots] provider callback provider=weixin ... text=测试
   
✅ Step 2: Task DISPATCHED
   Log: 00:54:40 [zcode-task-service] sendPrompt started
   
✅ Step 3: Reply GENERATED
   Log: 00:54:58 snapshot {assistantMessages:3, contentChars:161, completed}
   
❌ Step 4: Reply DELIVERED ← THIS STEP IS MISSING
   Log: (no reply-send log line, no error, nothing after this)

Critical Observation:

There is absolutely no log entry for the reply send operation. The system generates the response successfully but never attempts (or never logs) the outbound delivery to WeChat.

Log Evidence

ZCode Main Logs (`~/.zcode/v2/logs/2026-08-31.log`):

00:54:39 [bots] provider callback provider=weixin ... text=测试 ("test")
         ↑ Message received from WeChat
         
00:54:40 [zcode-task-service] sendPrompt started
         ↑ Dispatched into task queue
         
00:54:58 snapshot {assistantMessages:3, contentChars:161, completed}
         ↑ Agent finished generating reply
         
[ NOTHING AFTER THIS POINT ]
         ↑ No send attempt, no error, no delivery log

CLI Logs (`~/.zcode/cli/log/*.jsonl`):

Result: zero bot-related entries all day
       ↑ The reply send operation never executes locally

Troubleshooting Attempted

Attempt	Result
Full GUI restart (including tray)	❌ No effect
Removed stale `webRemoteControlExternalRelayDevice` binding	⚠️ Drop warnings gone, but replies still lost (not the relay cause)
Rebound bot session workspace	❌ Routing works fine, replies still lost
Deleted bot + re-scanned	❌ Brand-new cloud bot account (704136178063@im.bot), fresh credentials, identical reproduction

Conclusion from Testing:

"The outbound reply path looks broken in 3.10.1 — inbound → task → agent all work; only the final delivery to WeChat is silently lost."

— Jiamo.im

Root Cause Analysis

Diagnosis: Outbound IPC Dispatch Bug

As identified by moderator review:

"You've hit an outbound IPC dispatch bug as it seems: the task completion handler generates the response but fails to trigger the weixin provider outbound delivery hook."

— Roman | Z (Volunteer/Mod)

Likely Location of Failure:

┌─────────────────────────────────────────────────────────────┐
│                    MESSAGE FLOW                            │
├─────────────────────────────────────────────────────────────┤
│                                                             │
│  WeChat Server                                              │
│       │                                                     │
│       │ ① Message Received  ✅                               │
│       ▼                                                     │
│  ZCode Inbound Handler                                     │
│       │                                                     │
│       │ ② Create Task  ✅                                    │
│       ▼                                                     │
│  Task Service / Agent                                       ││       │                                                     │
│       │ ③ Generate Reply  ✅                                 │
│       ▼                                                     │
│  Task Completion Handler                                   │
│       │                                                     │n│       │ ④ Trigger Provider Send Hook  ❌ BROKEN HERE        │
│       │    (weixin outbound delivery never fires)           │n│       ▼                                                     │n│  [GAP] ← Reply sits here, never sent                        │n│                                                             │n│  WeChat Client (User's Phone)                              │n│       │                                                     │n│       │ ⑤ Receive Reply  ❌ NEVER ARRIVES                   │n│                                                             │
└─────────────────────────────────────────────────────────────┘

Possible Technical Causes:

1. Missing Event Emitter / Callback Registration

// Current (possibly broken):
taskService.on('complete', async (task) => {
  const reply = task.response;
  // Missing: await weixinProvider.send(reply);
  // Or: event not registered for weixin provider
});

2. Provider-Specific Dispatch Logic Missing

Task completion handler may have generic logic that doesn't cover WeChat's specific API requirements
WeChat long-polling mode may need different delivery mechanism than other providers

3. Async/Await Gap or Unhandled Promise

// Possible bug pattern:
taskService.on('complete', (task) => {
  weixinProvider.send(task.response);  // Missing 'await'!
  // Or: Promise not returned, error swallowed
});

4. Configuration/Registration Issue in 3.10.1

WeChat provider may not be properly registered in the outbound dispatcher
Could be a regression introduced in 3.10.1 (worked in earlier versions?)

5. Silent Error Swallowing

Send attempt may fail with caught exception that's logged nowhere
Or send may throw in unobserved promise chain

Related Issues

Similar to: #200 (Referenced by Reporter)

This appears to be the same class of bug as previously reported issue #200
Both involve outbound delivery failures where inbound + processing work fine
Linking this report to #200 for engineering team correlation

Proposed Fix

Immediate Investigation Required:

Trace Task Completion Code Path
- Find where taskService emits 'complete' event
- Verify WeChat provider's send handler is registered
- Check if provider-specific dispatch logic exists for weixin

Add Logging at Critical Points

// Add temporary debug logging:
taskService.on('complete', async (task) => {
  console.log('[DEBUG] Task complete, provider:', task.provider);
  console.log('[DEBUG] Response length:', task.response?.length);
  
  try {
    await providers[task.provider]?.send(task.response);
    console.log('[DEBUG] Send success');
  } catch (err) {
    console.error('[DEBUG] Send failed:', err);  // Currently missing!
  }
});

Verify Provider Registry
- Check if weixin provider is in the active providers map
- Confirm send() method exists and is callable
- Test with mock WeChat delivery endpoint
Check for Regression
- Identify if this worked in 3.9.x or earlier
- Git bisect between working version and 3.10.1 to find breaking change

Workarounds (For Users Until Fix)

Current Status: No Known Workaround

All attempted workarounds by reporter failed:

❌ Restart doesn't fix
❌ Rebinding workspace doesn't fix
❌ Fresh bot account doesn't fix
❌ Removing stale bindings doesn't fix

Potential (Untested) Workarounds:

Downgrade to earlier ZCode version (if 3.9.x worked)
Use different connection mode (if available: webhook instead of long-polling)
Switch to different bot platform temporarily (Discord, Slack, etc.)

Impact Assessment

Metric	Value
Feature Affected	WeChat bot outbound messaging (100% broken)
ZCode Versions Affected	3.10.1 (confirmed); possibly others
Platforms Affected	Linux (confirmed); likely all platforms
Plans Affected	GLM Coding Plan (and likely others)
Bot Commands Affected	All (/status, etc.) — same silent failure
Error Visibility	NONE — completely silent, no logs
User Impact	CRITICAL — bot appears broken to end users

Additional Notes

Why This Is Particularly Problematic:

Silent Failure = Impossible to Self-Diagnose
- Users have no indication what went wrong
- No error codes, no error messages, no log entries
- Requires deep system knowledge to even identify the failure point
Affects Production Bot Deployments
- WeChat bots are often used for customer service, notifications, automation
- Silent failure means users don't know their bot is broken
- Could miss important interactions for hours/days before noticing
Debugging Quality Is Excellent
- Reporter provided textbook-quality bug report
- Clear reproduction steps, environment details, log evidence
- Already ruled out common causes (restarts, rebinding, fresh credentials)
- This should make fixing relatively straightforward for engineering team

Moderator Assessment:

"This is a textbook bug report."

— Roman | Z (Volunteer/Mod)

Discord Thread Reference

Original Report: Discord community thread
Reporter: Jiamo.im
Moderator Review: Roman | Z (Volunteer/Mod) — confirmed as IPC dispatch bug, requested GitHub submission

Related Issue: #200 — similar outbound delivery failure

Submitted by: Roman Galaxys10 (Roman) — Z.ai Volunteer Ambassador
Discord: bignavi_x
GitHub: romangalaxys10-spec
Source: Discord Community — User: Jiamo.im
Submitted With Permission: User explicitly requested submission on their behalf

[Bug] ZCode 3.10.1 WeChat Bot: Replies Generated but Never Delivered — Silent Outbound Failure (Similar to #200)

Description