A handler takes an event by returning and asks for it again by throwing;
any mesh/event answer but an error is taken. Written down in the README
where event handling is, with what follows for a handler: throw only when
the work was not done, and be safe to run twice.
Both SDKs added the handler before asking the runtime and kept it when the
runtime refused, so a module that asks again until it is taken (every Go
consumer does) ran its handler once per attempt for every event. A refused
subscribe now removes its handler; one the Go runtime did not answer in
time is kept, since the runtime may have bound it.
Task 3.7 of novox/hq ADR 0116, and the whole of the sdk's diff for the bus
change. Three comments said AMQP where they meant 'message headers' and 'a
broker client'; the code never spoke it, which is why no module is rebuilt
for any of this (ADR 0039).
emit stamps the ADR 0047 headers — x-event-id, x-source, x-node, x-time,
content-type, and optional x-causation-id / x-schema — and publishes the
body as only the domain payload. on() reconstructs the Event from those
headers. Event gains id (the x-event-id a consumer dedups on) plus the
optional causation/schema. EventHeaders joins the contracts spine.
Supersedes the first cut that carried source/node/time in the body.
Claude-Session: https://claude.ai/code/session_01LrgweAeERJYBg88c5cKDzF
The lighter sibling of provisioning — 1:many and broadcast, no credential,
just the broker's topic routing. A thin, audit-ready surface over the
broker's publish/subscribe:
- emit(type, body): publishes an Event carrying who emitted it (MESH_MODULE),
on which node (MESH_NODE) and when (ISO timestamp) — so a listener can
build a real audit trail.
- on(pattern, handler): react to events by topic pattern. The audit logger
is just on("#", ...).
Tested: a module emits; a targeted listener (module.umami.#) hears only its
events, the audit sink (#) hears every module's, and the metadata audit
needs is present.
The declared side — a manifest's emits/consumes, so the mesh knows the
event graph — and the audit-logger module are the next pieces.
Claude-Session: https://claude.ai/code/session_01LrgweAeERJYBg88c5cKDzF
jochen
jschoubben