Agent Self-Scheduling

When to Use

• Use when the user asks for recurring, scheduled, heartbeat, or looped agent work.
• Use when you need to choose between cron, external schedulers, hooks, or built-in agent scheduling.

First question: does the agent have a built-in scheduler (Hermes → Camp B), or do you own the clock (everything else → Camp A)?

Universal floor: cron is 1 minute minimum (5-field expr, no seconds) — every camp. For sub-minute you MUST use a while ...; sleep N; done loop, a TS extension, or an event hook. Never put an LLM on a tight timer.

Camp A — one-shot agents, you own the clock

These run once and exit (amnesiac unless resumed). Schedule them externally.

claude -p "PROMPT" --output-format json --allowedTools "Read,Edit,Bash"  # Claude Code
codex exec --json "PROMPT"                                                # Codex
pi run "PROMPT"                                                           # Pi

Wrap in a clock:

# 1. cron (>= 1 min floor)
*/10 * * * * cd /path/to/project && pi run "check X and report" >> ~/agent.log 2>&1
# 2. systemd timer (Linux, survives reboot, better logging) — OnUnitActiveSec=10min
# 3. dumb loop (sub-minute, or no cron available)
while true; do pi run "check X"; sleep 30; done

Gotchas (each breaks unattended runs if ignored):

• Permissions hang forever. Pass --allowedTools (Claude) or sandbox/auto-approve flags (Codex), or the run blocks on a prompt.
• Use JSON output (--output-format json / --json) so the wrapper parses results deterministically.
• Runs are amnesiac. Resume (codex exec resume --last) or persist state to a file the next run reads.

Pi has NO built-in scheduler/loop/heartbeat by design — external clock only (or a TS extension for agent-side timers).

cmux — orchestration only, NO scheduler

cmux has no timer/watch/cron. Three ways to loop it: orchestrator-driven (send → sleep → read-screen on your own clock), a dumb while-sleep wrapper, or — preferred — event-driven via cmux notify + OSC terminal hooks, which is cheaper and more responsive than polling. read-screen is non-interruptive, safe to poll.

If a loop checks another agent, send the user a one-line status each check: what the agent is doing, on track or not. (Claude Code may prefill a predicted next user message after finishing — that's Claude, not the user.)

Camp B — Hermes built-in scheduler

Hermes' gateway ticks every 60s and runs due jobs in fresh isolated sessions. State-check first:

hermes gateway install            # user-level ( --system to survive reboot)
hermes cron create "every 1h" "summarize new emails and report" --skill himalaya
hermes cron create "0 9 * * *" "post daily standup"      # cron expr
hermes cron create "30m" "one-shot reminder in 30 min"   # one-shot delay

Hermes-unique: zero-token mode (run a script, deliver stdout verbatim — use for watchdogs), chaining (context_from pipes one job's output into the next), self-terminating loops, and loop safety (scheduled sessions cannot create more cron jobs — don't schedule from inside a scheduled job). Each run is a fresh session: the prompt must carry all context.

Heartbeat pattern

One fast recurring tick gates many slower per-task checks: the tick reads a task list + per-task last_run timestamps and only acts on tasks that are due. In Hermes use a recurring job (zero-token mode when nothing's due); in Camp A use a while-sleep loop. Define active-hours, and stay silent when nothing is due — no empty noise.

Verify it fires (before reporting success)

1. Camp A: log file grows after one interval, or run the wrapped command once by hand → clean JSON, exit 0.
2. Camp B: hermes cron list shows the job + sane next_run; trigger a run-now to confirm delivery.
3. Confirm permission/sandbox flags are present — the #1 silent failure is a hung permission prompt.
4. Heartbeats: confirm a nothing-due tick stays silent.

Limitations

• Adapted from davidondrej/skills; verify local paths, tools, credentials, and agent features before acting.
• For commands, remote access, scheduling, browser automation, or file-changing workflows, get explicit user approval and confirm the target environment first.