mikkeli
73eff1c5d6
The app<->svc-gw channels have no wire format yet. Measured USB link drops (~3 s per power change, sleeping tablet invisible at link level) and yukart decision 24 already fix the required fields: heartbeat, command idempotency key, and utterance id/sequence/terminator/expiry. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2.1 KiB
type, status, updated
| type | status | updated |
|---|---|---|
| plan | active | 2026-10-09 |
Initial plan
What is defined
The envelope, the topic namespace, and the standard OBD-II signals — the ones whose names, units and ranges are fixed by the standard rather than by the car.
What is not
Z27AG-specific signals. They do not exist until Phase 2 identifies them from
observed traffic. They arrive as DBC entries plus registry rows with
source: "z27ag", one at a time as each is confirmed.
Composite payload shapes. gnss/fix, nav/guidance, nav/route and
system/<service> have their fields named in topics.json but no JSON Schema
yet. They get one when a publisher exists to constrain.
The app ↔ svc-gw boundary protocol. Bus topics are defined here, but the
two channels across the boundary (latest-wins state down, acknowledged commands
up) have no wire format yet. Project-yukart decision 24 (proposed) already
fixes what it must carry, because the USB link drops for ~3 s at every power
change and a sleeping tablet looks alive at the link layer:
- a heartbeat in both directions, with an agreed interval and timeout, so the Orin reaps a silent client instead of trusting TCP or link state;
- an idempotency key on every upstream command, so retries across a reconnect never act twice;
- for TTS, utterance id + chunk sequence + terminator + an expiry, so a reconnect can resume or drop an utterance rather than replay it blindly.
Defined when svc-gw and app-flutter first talk, not before.
Order
- Schema validation available to all three languages — the Rust services, the Python fixtures and the Dart client must reject a malformed message identically, or the contract is decorative.
gnss/fixschema, driven by whattool-mockreplays.- Z27AG signals, as Phase 2 confirms them.
Consumers
| Repo | Reads |
|---|---|
svc-core |
signals, envelope, DBC |
svc-gw |
topics, envelope |
svc-nav |
topics, envelope |
app-flutter |
topics, envelope, signals (for display units) |
tool-mock |
all of it — fixtures publish the real schema |