React to Events

Telemetry tells you what is true now. Events tell you what just changed. /sim/events is a growing NDJSON log: one JSON object per line, including situation-change, engine-state, flameout, docked, undocked, decoupled, and the schedule events.

/sim (in guest)

# Watch everything.
tail -f /sim/events

# Stop after the next flameout. grep sees one JSON line at a time.
tail -f /sim/events | grep -m1 '"type":"flameout"'

HTTP (host)

# SSE. Each event is a data: line containing the same JSON object.
curl -N http://127.0.0.1:4242/v1/events

Use the event as a wake-up, then read a fresh telemetry document before commanding anything. An event reports the transition, not a magic complete state machine in miniature.

The event gate

Events require telemetry_events=true, the default. tail -f works because the guest supplies a polling-friendly tail shim for /sim; GNU tail’s usual inotify expectation would be a tiny tragedy.

Next, make several writes genuinely simultaneous with Atomic batches.

Next: Atomic batchesCommit a set of same-phase controls in one game tick.