Bug type

Behavior bug (reply generated but not delivered)

Summary

In a persistent ACP session bound to a Discord thread the initial assistant response is delivered correctly.

After the user sends a second message in the same Discord thread:

• the message reaches the ACP session
• the ACP agent generates and stores a response
• the response is visible in the ACP session transcript / Web UI
• no assistant response is posted back to Discord

This reproduces consistently in my environment.

Steps to reproduce

1. Spawn a persistent Claude ACP session with:
   • runtime: "acp"
   • mode: "session"
   • thread: true
2. Wait for the initial ACP response in the newly created Discord thread.
3. Send another message directly in that Discord thread.
4. Inspect both the Discord thread and the ACP session transcript.

Expected behavior

Every user message sent in the bound Discord thread should reach the ACP session and the generated response should be delivered back to the same thread.

Actual behavior

The initial response is delivered to Discord.

On the second turn the user message reaches the ACP session and a response is generated successfully but the response remains only in the internal transcript / Web UI. No corresponding Discord message is emitted.

Live reproduction evidence

Reproduction 1

Discord thread:

• 2026-06-13T14:13:46Z: ACP session reports active
• 2026-06-13T14:14:01Z: initial assistant response is delivered
• 2026-06-13T14:15:46Z: user sends 直近で何をしていたか把握して
• no assistant response follows
• 2026-06-13T14:18:25Z: Discord receives only Session ended

ACP transcript:

• 2026-06-13T14:16:43Z: the second user message is recorded
• 2026-06-13T14:16:43Z: the ACP agent generates a complete response

That generated response does not appear in the Discord thread.

Reproduction 2

Discord thread:

• initial assistant response is delivered
• user sends Claudeと疎通はしている？
• no assistant response appears

ACP transcript:

• the user message is recorded
• the ACP agent generates a complete response beginning with ちょっと確認しますね
• that response is not delivered to Discord

Observed in both inspected sessions and consistently across other ACP thread attempts.

Environment

• OpenClaw: 2026.6.6 (8c802aa)
• Node.js: v22.22.1
• OS: Debian Linux x86_64
• Install method: global npm installation through nvm
• Channel: Discord
• ACP agent: Claude
• Session mode: persistent thread-bound ACP session

Related issues

• [Bug]: ACP sessions_send replies are not mirrored into the target worker’s bound Discord thread #46645 appears related but concerns sessions_send replies from a separate coordinator session. This reproduction uses a normal user message sent directly inside the bound Discord ACP thread.
• Bug: Parent final reply after sessions_yield can lose original channel delivery routing #91356 describes a similar symptom where a generated response remains visible only in the internal/Web UI transcript.
• fix(agents): carry provenance through active subagent wakes #92251 carries provenance through active subagent wakes but does not appear to include a live Discord-bound ACP second-turn reproduction.

Impact

Discord-bound persistent ACP sessions are effectively single-turn. Users cannot continue the conversation reliably even though ACP execution itself succeeds.