Cron delivery to Slack failing with "Unsupported channel: slack"

Environment

• Version: OpenClaw 2026.3.22 (e7d11f6)
• Platform: macOS (Darwin 25.2.0, arm64)
• Installation: Git source (/Users/aiden/clawdbot/)
• Gateway started: 2026-03-24 10:13:44 CDT

Problem

Cron jobs configured with delivery: {mode: "announce", channel: "slack", to: "user:U03QT833TC7"} are failing with error: "Unsupported channel: slack"

This affects both:

• sessionTarget: "isolated" + payload.kind: "agentTurn" jobs
• sessionTarget: "main" + payload.kind: "systemEvent" jobs

Configuration

Slack is properly configured and working:

"channels": {
  "slack": {
    "mode": "socket",
    "enabled": true,
    "botToken": "[REDACTED]",
    "appToken": "[REDACTED]",
    "dmPolicy": "pairing",
    "dm": {"enabled": true},
    "channels": {"C0ADJGJR55G": {"allow": true}},
    "nativeStreaming": true,
    "streaming": "partial"
  }
}

Gateway logs show Slack connecting successfully:

2026-03-24T10:14:27.987-05:00 [health-monitor] started

Reproduction

Create a cron job with Slack delivery:

{
  "name": "Test Job",
  "schedule": {"kind": "cron", "expr": "*/5 * * * *"},
  "sessionTarget": "isolated",
  "payload": {
    "kind": "agentTurn",
    "message": "Test message"
  },
  "delivery": {
    "mode": "announce",
    "channel": "slack",
    "to": "user:U03QT833TC7"
  }
}

Result: Job completes but delivery fails with "Unsupported channel: slack"

Expected Behavior

Cron jobs should successfully deliver messages to Slack DMs when configured with proper delivery settings.

Actual Behavior

• Job execution succeeds
• Message is generated
• Delivery fails with "Unsupported channel: slack"
• deliveryStatus shows "unknown"

Workaround

Direct Slack API calls work fine:

curl -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"channel":"U03QT833TC7","text":"Test"}'

Returns {"ok":true} successfully.

Additional Context

• Multiple cron jobs affected (morning reminders, AI digest, daily drip)
• Issue appeared after updating job from sessionTarget: "main" to sessionTarget: "isolated"
• But reverting to sessionTarget: "main" also fails with same error
• Gateway restart did not resolve issue

Logs

Cron run output:

{
  "status": "error",
  "error": "Unsupported channel: slack",
  "deliveryStatus": "unknown"
}

No relevant errors in ~/.openclaw/logs/gateway.log related to delivery failure.