Timer Build Monitor

Timer Skill — Build Monitor

A minimal timer skill for one-shot async checks (build monitoring, long-running tasks). Wraps sessions_spawn with named timer tracking and status reporting.

Usage

# Set a timer
$timer "check eas build in 20 minutes" --name eas-build-v018

# Check active timers
$timer list

# Cancel a timer
$timer cancel eas-build-v018

Architecture

User sets timer → Parse intent → Spawn subagent (isolated, timeout) 
  → Subagent sleeps → Checks status → Reports back via message
  → If success: update state, notify user
  → If timeout: update state, notify user "timer expired"

Files

• SKILL.md — This file. Usage + workflow.
• scripts/timer.sh — CLI wrapper. Parses $timer commands, spawns subagents.
• scripts/state.sh — CRUD timer state (JSON file in ~/.openclaw/timers/).

Why BYO Instead of NervTimer

Trade-off: Subagent pattern is simpler but doesn't survive session restarts. For persistent timers across restarts, use OpenClaw native cron tool or install NervTimer.

Why BYO Instead of NervTimer

Trade-off: Subagent pattern is simpler but doesn't survive session restarts. For persistent timers across restarts, use OpenClaw native cron tool or install NervTimer.

State Format

{
  "timers": {
    "eas-build-v018": {
      "id": "eas-build-v018",
      "status": "running",
      "createdAt": "2026-05-18T04:35:00Z",
      "expiresAt": "2026-05-18T04:55:00Z",
      "task": "check eas build status",
      "sessionKey": "agent:main:subagent:xxx",
      "result": null
    }
  }
}

Commands

$timer

Spawn a subagent to execute the described task after the implied delay. If no delay is stated, ask the user for clarification.

$timer list

Show all active timers with status and time remaining.

$timer cancel

Kill the subagent session and mark timer as cancelled.

Implementation Notes

• Uses sessions_spawn with mode="run" and runTimeoutSeconds
• Subagent receives the full task description + current context
• Subagent reports back via sessions_send or completion event
• No cron dependency — pure subagent-based
• State file is human-readable JSON for debugging