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How to Debug Message Failed Errors in OpenClaw Cron Jobs

#openclaw #cron #slack #debugging

TL;DR

When OpenClaw cron jobs fail with "Message failed" errors, the execution layer (Mac Mini + Gateway) is often healthy—the problem is in the delivery layer (Slack). This guide shows how to isolate and fix messaging failures.

Prerequisites

  • OpenClaw Gateway running
  • Cron jobs configured
  • Slack channel delivery enabled

The Problem 

Error: Message failed
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Six cron jobs (autonomy-check, trend-hunter, app-metrics, app-resubmission-daily, factory-bp-revenue, factory-bp-efficiency) showed this error:

  • Mac Mini infrastructure: healthy
  • OpenClaw Gateway: running
  • Some crons (build-in-public, article-writer): working fine

Step 1: Identify the Error Layer

OpenClaw cron jobs operate in 3 layers:

Layer Role How to Check
Infrastructure Mac Mini/VPS, OpenClaw Gateway openclaw gateway status
Job Execution Cron script execution Check cron log files
Delivery Layer Slack/messaging openclaw message send test

Problem location: Delivery layer. Execution itself was successful.

Step 2: Verify Slack API Token 

# Check if environment variable is set
echo $SLACK_BOT_TOKEN

# Verify correct format (starts with xoxb-)
# Invalid: empty, old token, wrong scope
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Step 3: Validate Channel ID

You must use the channel ID, not the channel name.

# Channel ID format: C091G3PKHL2
# How to find: Slack app → Channel → Right-click → View channel details → ID at bottom

# Wrong
openclaw message send --target '#metrics'  # NG: channel name

# Correct
openclaw message send --target 'C091G3PKHL2'  # OK: channel ID
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Step 4: Manual Test for Network Connectivity 

# Minimal message send test
openclaw message send \
  --channel slack \
  --target 'C091G3PKHL2' \
  --message 'test'
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If successful: Token and channel ID are correct → check cron job delivery settings
If failed: Token or channel ID is incorrect

Step 5: Check Cron Job Delivery Settings

OpenClaw cron jobs specify delivery via the delivery field:

{
  "delivery": {
    "mode": "announce",
    "channel": "slack",
    "to": "C091G3PKHL2"
  }
}
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Common mistakes:

Mistake Correct Setting
"mode": "silent" "mode": "none" or "announce"
"to": "#metrics" "to": "C091G3PKHL2"
Missing delivery field Add it

Step 6: Reference Successful Patterns from History 

# Check configuration of previously successful cron jobs
openclaw cron list --includeDisabled true | jq '.[] | select(.name == "build-in-public")'
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Copy the delivery settings from working jobs and apply to failing ones.

Step 7: Consider Retry Logic (Future Improvement)

OpenClaw has no message delivery retry mechanism. Consider:

  1. Cron-level retry: Script retries openclaw message send 3 times
  2. Fallback on failure: Write to local log file
  3. Monitoring alerts: Notify alternative channel on delivery failure

Key Takeaways

Lesson Detail
Layer isolation is critical Infrastructure can be healthy while delivery fails
Use channel ID Not channel name (#metrics) but ID (C091G3PKHL2)
Copy successful patterns Reference working job configurations
Manual test with minimal config Verify with openclaw message send

Diagnosis result: System infrastructure is healthy. Fix delivery settings to resolve.

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