openclaw - 💡(How to fix) Fix message tool: 'Invalid session key' on proactive sends to Zulip stream topics (2026.4.1) [1 participants]

Bug Report

OpenClaw version: 2026.4.1 (da64a97) Channel plugin: Zulip (custom, loaded via plugins.load.paths) OS: Linux 6.8.0-107-generic (x64)

Summary

The message tool fails with Invalid session key on all proactive sends to Zulip streams. Normal conversation replies work fine. This affects automated sends from heartbeat scripts, watchdog alerts, and any agent-initiated message tool call.

Steps to Reproduce

1. Configure OpenClaw with a Zulip channel plugin
2. Have an active session in a Zulip stream (e.g. Desert Power > Command Center)
3. Attempt a proactive send via the message tool:

   { "action": "send", "channel": "zulip", "target": "stream:Desert Power:Command Center", "message": "test" }

4. Observe: [tools] message failed: Invalid session key

Root Cause Analysis

The message tool constructs session key agent:main:zulip:channel:desert power from the target parameter. This key IS present in sessions.json with a valid sessionId UUID. However, resolveSessionFilePath throws (caught by the try/catch at gateway-cli line 17921), returning null and triggering the Invalid session key error response.

sessions.json entry for the key:

{
  "sessionId": "<uuid>",
  "chatType": "channel",
  "channel": "zulip",
  "groupId": "stream:desert power"
}

The session file (<uuid>.jsonl) exists on disk and is readable. The failure appears to be inside resolveSessionFilePath itself despite the file being present.

Impact

• ✅ Conversation replies work (use active session correctly)
• ❌ All proactive message tool sends fail
• ❌ Delivery queue accumulates and never drains
• ❌ Heartbeat alerts, watchdog notifications, scheduled sends all broken

Both affected systems upgraded from 2026.3.31 → 2026.4.1 today; the issue appears to be a regression in 2026.4.1.

Workaround

None found. The delivery queue accumulates indefinitely.

Additional Context

• Two separate OpenClaw instances (different user accounts on same host) both exhibit identical behavior
• openclaw status shows gateway healthy, Zulip probe ok=true
• Log entry immediately before error: session maintenance would evict active session; skipping enforcement — possibly related?