docs/adr/app-run-wire-codecs.md
Status: accepted for C1.2; the contracts ship dark and C1.3 owns wiring.
src/app_run/transport.ts defines two closed, strict allowlists. Renderer
dispatch may decode only AppRunIntentEventSchema; trusted main-process
adapters may decode AppRunProducerEventSchema. Unknown event kinds and
unknown payload fields fail decoding. The combined schema exists for tests and
transport-neutral tooling, not as permission to dispatch producer events from
a renderer.
Remote intents are entity-relative: AppRunKeySchema.appId is their sole app
identity, and AppRunDispatchSchema is the per-definition admission boundary
assembled after the generic transport decodes key and event. Intents carry an
immutable operationId and startedAt. START and RESTART are state-sensitive
and require expectedRevision. STOP_REQUESTED is cancellation: its request
operationId is distinct from, and cannot replace, the required
activeInvocationRef; dispatch admission requires that ref to belong to the
routed key. MANUAL_RELOAD is idempotent/current-agnostic. There is no
presentation-only member of the current RunEvent union; applyUrl and
reload-token commands become typed post-commit presentation consumers in C1.3
rather than a second domain mutation path.
Every current event has an explicit refined destination:
Current RunEvent | Refined wire event | Admission |
|---|---|---|
| START | START | state-sensitive intent |
| RESTART | RESTART (operation: restart) | state-sensitive intent |
| REBUILD | RESTART (operation: rebuild, no options) | state-sensitive intent |
| STOP | STOP_REQUESTED | cancellation intent; active invocation required |
| MANUAL_RELOAD | MANUAL_RELOAD | idempotent intent |
| EXTERNAL_RESTART | EXTERNAL_RESTART_STARTED | host-only producer admission |
| RUN_IPC_RESOLVED | PROCESS_SPAWNED | host-only settlement |
| RUN_IPC_FAILED | PROCESS_FAILED | host-only settlement |
| STOP_IPC_RESOLVED | PROCESS_STOPPED | host-only settlement |
| STOP_IPC_FAILED | PROCESS_STOP_FAILED | host-only settlement |
| PROXY_READY | PROXY_READY | host-only producer |
| HMR_DETECTED | HMR_DETECTED | host-only producer |
| RELOAD_DONE | RELOAD_COMPLETED | host-only settlement |
| APP_EXIT | PROCESS_EXITED | host-only producer |
The spawn result remains distinct from PROXY_READY. A proxy URL may arrive
first and is buffered in RunState.pendingUrl; PROCESS_SPAWNED later commits
ready state and exposes it. Combining those events would change behavior.
HMR_DETECTED is the one refinement that needs producer work in C1.3: current
log parsing supplies only appId, so the main producer must attach the active
invocation ref at capture time. Ref-less legacy producer compatibility is not
part of the new allowlist, as decided by B0.
APP_EXIT also has one ordering that cannot be represented by unchanged
RunState: after STOP_IPC_RESOLVED creates stopped with null exit details, a
matching late APP_EXIT is deliberately ignored by the transition and retained
in the manager's admittedExitStores sidecar. C1.3 deletes that sidecar, so a
matching PROCESS_EXITED received after PROCESS_STOPPED must enrich the
authoritative stopped state (or an equivalent single-owner read-model fact)
before projection. This is required C1.3 input; C1.2 does not change the
transition.
projectAppRunRemoteSnapshot(appId, revision, state) maps authoritative
RunState into:
startedAt where the current state retains them;Idle has no invocation. Starting exposes its operation and timestamp but not a
buffered pendingUrl; that URL becomes public only after spawn settlement.
Ready and reloading expose their URL. Reloading reports operation reload,
while stopped exposes only an observed process exit. Errored exposes only the
operation error and conservatively keeps stop available because a failed stop
can leave the process alive. A stopped state with no observed exit timestamp
exposes exit: null, matching the current UI read model. The existing state
does not retain the initiating operation or timestamp after settlement, so
those fields are null in ready, stopped, and errored unless C1.3 deliberately
enriches the authoritative state.
The projection explicitly excludes child-process/process handles, internal paths (app path, cwd, executable paths), command/runtime data, producer callbacks, and renderer callback registries. All schemas accept JSON data only: no callbacks, Error instances, Maps/Sets without an explicit encoding, or resource handles cross the wire. Strict rejection tests and a compile-time excluded-key assertion guard that boundary.
C1.3 registers the key, intent, dispatch-admission, producer, and snapshot
schemas with the main actor definition; injects the decoded key's appId when
translating accepted entity-relative intents into the existing transition
semantics; binds runtime producers to invocation refs; and publishes this
projection after authoritative commits. The generic actor envelope owns
revision/receipt/subscription mechanics, while this module owns domain payload
validation.
Open cutover questions are limited to integration choices:
operationId is reused as the main invocation
operation ID or remains a distinct idempotency identity while main mints
correlation identity, preserving B0's authoritative mint boundary.startedAt; supporting that requires enriching RunState, not inferring
identity from timestamps.C1.3 must additionally settle the non-optional late-exit representation described above; it is a known behavior-preservation requirement rather than an open product choice.