<!-- Agent: developer | Task: #heartbeat-skill | Session: 2026-03-07 -->

Heartbeat Skill

Overview

The Heartbeat Ecosystem keeps agent-studio healthy, indexed, and informed by running 7 background loops via Claude Code's cron scheduler (CronCreate/CronList/CronDelete).

Key constraint — session-scoped: All loops die when the terminal closes. Use Loop 0 (auto-reschedule) to prevent silent 3-day expiry, and re-run Quick-Start commands after each session restart.

---

Quick-Start — Activate All Loops Now

Run these /loop commands in your Claude Code session:

/loop 2h Heartbeat tick: Spawn heartbeat-orchestrator subagent via Task({ task_id: 'hb-reflection-' + Date.now(), subagent_type: 'heartbeat-orchestrator' }) to run reflection-check.cjs. Reply HEARTBEAT_OK after spawning.

/loop 4h Heartbeat tick: Spawn heartbeat-orchestrator subagent via Task({ task_id: 'hb-indexing-' + Date.now(), subagent_type: 'heartbeat-orchestrator' }) to check mtime of .claude/context/code-index/metadata.json and reindex if older than 4 hours or missing. Reply HEARTBEAT_OK after spawning.

/loop 30m Heartbeat tick: Spawn heartbeat-orchestrator subagent via Task({ task_id: 'hb-drain-' + Date.now(), subagent_type: 'heartbeat-orchestrator' }) to run context-drain.cjs and report stdout. Reply HEARTBEAT_OK after spawning.

/loop 24h Heartbeat tick: Spawn heartbeat-orchestrator subagent via Task({ task_id: 'hb-evolution-' + Date.now(), subagent_type: 'heartbeat-orchestrator' }) to run evolution-check.cjs. Reply HEARTBEAT_OK after spawning.

---

The 7 Heartbeat Loops

Loop 0: Auto-Reschedule (every 2 days — MANDATORY)

Prevents silent 3-day expiry. CRITICAL ORDER: Always CronCreate new tasks BEFORE CronDelete old ones.

CronCreate({
  schedule: '0 0 */2 * *',
  task: 'Self-maintenance: CronList() to inventory active tasks. Identify missing heartbeat loops from the expected set (reflection-2h, evolution-24h, briefing-8am, indexing-4h, drain-30m, telegram-5m, research-7am, reschedule-2d). Recreate any missing tasks using schedules in .claude/context/plans/heartbeat-ecosystem-design-2026-03-07.md. Report recreated task IDs.',
});

Loop 1: Continuous Reflection (every 2h)

Extracts patterns from session transcripts before they are lost.

CronCreate({
  schedule: '0 */2 * * *',
  task: "Heartbeat tick: Spawn heartbeat-orchestrator subagent via Task({ task_id: 'hb-reflection-' + Date.now(), subagent_type: 'heartbeat-orchestrator' }) to execute this tick. The orchestrator must: (1) call TaskUpdate(in_progress), (2) run `node .claude/tools/cli/reflection-check.cjs`, (3) if stdout is HEARTBEAT_OK, call TaskUpdate(completed) and exit. Do NOT run the script directly in the router session. Reply HEARTBEAT_OK immediately after spawning.",
});

Loop 2: Agent Evolution (every 24h at 3am)

Applies accumulated learnings to improve agent definitions.

CronCreate({
  schedule: '0 3 * * *',
  task: "Heartbeat tick: Spawn heartbeat-orchestrator subagent via Task({ task_id: 'hb-evolution-' + Date.now(), subagent_type: 'heartbeat-orchestrator' }) to execute this tick. The orchestrator must: (1) call TaskUpdate(in_progress), (2) run `node .claude/tools/cli/evolution-check.cjs`, (3) if stdout is HEARTBEAT_OK, call TaskUpdate(completed) and exit. Do NOT run the script directly in the router session. Reply HEARTBEAT_OK immediately after spawning.",
});

Loop 3: Morning Briefing (8am weekdays)

Summarizes overnight state and suggests priority work.

CronCreate({
  schedule: '0 8 * * 1-5',
  task: 'Morning briefing: Spawn researcher via Task() to read issues.md, learnings.md, git log, and generate morning briefing report. Do NOT wait for sub-agent. Reply HEARTBEAT_OK and exit.',
});

Loop 4: Codebase Indexing (every 4h)

Keeps hybrid search index fresh.

CronCreate({
  schedule: '0 */4 * * *',
  // Fixed 2026-04-21: was bm25-index.json which never exists — real artifact is metadata.json
  task: "Heartbeat tick: Spawn heartbeat-orchestrator subagent via Task({ task_id: 'hb-indexing-' + Date.now(), subagent_type: 'heartbeat-orchestrator' }) to execute this tick. The orchestrator must: (1) call TaskUpdate(in_progress), (2) check mtime of .claude/context/code-index/metadata.json via Bash; if older than 4 hours or missing, run `pnpm code:index:reindex`, (3) call TaskUpdate(completed) and exit. Do NOT run the script directly in the router session. Reply HEARTBEAT_OK immediately after spawning.",
});

Loop 5: Context Drain + Clear (every 30min)

Detects pipeline idle state — warns user, does NOT auto-clear.

CronCreate({
  schedule: '*/30 * * * *',
  task: "Heartbeat tick: Spawn heartbeat-orchestrator subagent via Task({ task_id: 'hb-drain-' + Date.now(), subagent_type: 'heartbeat-orchestrator' }) to execute this tick. The orchestrator must: (1) call TaskUpdate(in_progress), (2) run `node .claude/tools/cli/context-drain.cjs`, (3) reply with the exact stdout output, then call TaskUpdate(completed) and exit. Do NOT run the script directly in the router session. Reply HEARTBEAT_OK immediately after spawning.",
});

Loop 6: Telegram Polling (every 5min)

Polls Telegram Bot API for user messages and routes to agents.

Configuration required:

1. Create Telegram bot via @BotFather → get token
2. Set TELEGRAM_BOT_TOKEN=your_token in .env
3. Start loop after .env is configured

CronCreate({
  schedule: '*/5 * * * *',
  task: "Heartbeat tick: Spawn heartbeat-orchestrator subagent via Task({ task_id: 'hb-telegram-' + Date.now(), subagent_type: 'heartbeat-orchestrator' }) to execute this tick. The orchestrator must: (1) call TaskUpdate(in_progress), (2) run `node .claude/tools/cli/telegram-poll.cjs`, (3) if stdout is HEARTBEAT_OK, call TaskUpdate(completed) and exit. Do NOT run the script directly in the router session. Reply HEARTBEAT_OK immediately after spawning.",
});

Discord note: Discord uses webhooks (push-based) rather than polling. Send messages via Discord webhook URL, but receiving requires a persistent process — recommend Telegram for bidirectional communication.

Loop 7: ArXiv + Exa Research Digest (daily at 7am)

Surfaces relevant academic papers and web news. Delegates to the dedicated monitor skills.

CronCreate({
  schedule: '0 7 * * *',
  task: 'Research digest: Spawn researcher via Task() to invoke arxiv-monitor and exa-monitor skills. Do NOT wait for sub-agent. Reply HEARTBEAT_OK and exit.',
});

Dedicated skills: arxiv-monitor (every 6h standalone) | exa-monitor (every 4h standalone) Config: ARXIV_KEYWORDS and EXA_MONITOR_TOPICS env vars (see .env.example)

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Activation via CronCreate (Full Ecosystem)

To activate all 8 tasks programmatically:

// Invoke via Skill({ skill: 'heartbeat' }) — this skill registers all loops

// Loop 0: Auto-reschedule (must be first — keeps everything alive)
CronCreate({ schedule: '0 0 */2 * *', task: '...' }); // see Loop 0 above

// Loop 1: Reflection
CronCreate({ schedule: '0 */2 * * *', task: '...' }); // see Loop 1 above

// Loop 2: Evolution
CronCreate({ schedule: '0 3 * * *', task: '...' }); // see Loop 2 above

// Loop 3: Morning Briefing
CronCreate({ schedule: '0 8 * * 1-5', task: '...' }); // see Loop 3 above

// Loop 4: Indexing
CronCreate({ schedule: '0 */4 * * *', task: '...' }); // see Loop 4 above

// Loop 5: Drain Check
CronCreate({ schedule: '*/30 * * * *', task: '...' }); // see Loop 5 above

// Loop 6: Telegram Polling
CronCreate({ schedule: '*/5 * * * *', task: '...' }); // see Loop 6 above

// Loop 7: Research Digest
CronCreate({ schedule: '0 7 * * *', task: '...' }); // see Loop 7 above

// Verify all registered
CronList();

---

Monitoring & Management

Check Ecosystem Status

CronList(); // Returns all active tasks with IDs, schedules, next fire time

Stop Individual Loop

CronDelete({ id: 'abc12345' }); // Use ID from CronList()

Stop All Loops

// Get all IDs via CronList(), then delete each
const tasks = await CronList();
for (const task of tasks) {
  CronDelete({ id: task.id });
}

---

Cron Expression Reference

minute hour day-of-month month day-of-week
*/5    *    *             *     *            = Every 5 minutes
0      */2  *             *     *            = Every 2 hours
0      8    *             *     1-5          = Weekdays at 8am
0      */4  *             *     *            = Every 4 hours
*/30   *    *             *     *            = Every 30 minutes
0      0    */2           *     *            = Every 2 days at midnight

Supported: wildcards (*), single values (5), steps (*/15), ranges (1-5), comma lists (1,15,30). NOT supported: L, W, ?, named aliases (MON, JAN).

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Constraints & Risks

Risk	Mitigation
session-scoped: loops die on terminal close	Re-run Quick-Start commands on each session restart
3-day auto-expiry: tasks silently self-delete	Loop 0 auto-reschedule runs every 2 days
50-task cap: max concurrent scheduled tasks	8 loops = 16% of cap; leaves 84% for ad-hoc tasks
No catch-up: missed fires are NOT replayed	Design loops to be idempotent (safe to skip)
Jitter: up to 15min delay on recurring tasks	Expected; design checks to tolerate timing variance
Telegram token not configured	Loop 6 gracefully skips if TELEGRAM_BOT_TOKEN unset

---

Integration with Memory System

• Loop 1 integrates with memory-rotator.cjs for automatic file rotation
• Loop 2 reads agent-health.json for degradation signals
• Loop 7 appends to .claude/context/memory/research-digest.md
• Loop 5 uses TaskList() same as the router drain gate

Related Skills

• scheduled-tasks — low-level cron patterns (this skill builds on it)
• arxiv-monitor — dedicated ArXiv paper monitor (ARXIV_KEYWORDS, 6h interval)
• exa-monitor — dedicated Exa web search monitor (EXA_MONITOR_TOPICS, 4h interval)
• telegram-polling — Telegram Bot API polling (TELEGRAM_BOT_TOKEN required)
• task-management-protocol — task tracking patterns
• memory-search — semantic memory queries used by loop prompts