Health Check

docker ps only tells you the process hasn't crashed — a hung scheduler loop looks identical to a healthy one. chime exposes a liveness signal that answers "is the scheduler actually ticking?", not "did the last Discord send succeed?".

How it works

• On every tick the daemon writes the current timestamp to a heartbeat file (default /tmp/chime.heartbeat, override with CHIME_HEARTBEAT_PATH). The write happens before any Discord request, so the signal is independent of network reachability, and is repeated after every Discord request, so a tick that sends several messages to a slow Discord is not mistaken for a hung one.
• The chime health subcommand reads that file's mtime and exits 0 when it is fresh — now - mtime <= 2 * tick_interval_sec — and non-zero with a one-line stderr message otherwise (stale, missing, or unreadable). It reads the tick interval from the same CHIME_CONFIG, and does not require any webhook env var.

The container image already wires this into a HEALTHCHECK (exec-form, since distroless has no shell), so docker ps / docker inspect report health automatically. To set it explicitly in docker/compose.yml:

healthcheck:
  test: ["CMD", "/usr/local/bin/chime", "health"]
  interval: 30s
  timeout: 5s
  start_period: 10s
  retries: 3

Without Docker you can call chime health from any supervisor or monitoring probe — its exit code is the contract.