The session event vocabulary carried two standalone trace-only events that
were not load-bearing as separate records. Fold their facts into nearby
load-bearing events and delete the standalone variants.
- Token usage now rides on `assistant/message` as an optional `usage` field —
the assembled model output and its accounting travel together. The loop folds
`assembler.usage` onto the append instead of emitting a separate `usage`
event.
- The max-tokens path is the no-data-loss host: a step cut off with usage but
EMPTY content (e.g. only a dropped tool call) previously emitted a standalone
`usage`; it now records an empty-content `assistant/message { content: [],
usage }`. `deriveMessages()` skips empty-content assistant messages, so the
usage host never injects a spurious content-less assistant turn into the
provider transcript. A step with neither content nor usage appends nothing.
- An operational error's step number now rides on `turn/end.reason` for
`kind: 'error'` (`{ kind: 'error', step, message, code? }`) — the durable
turn outcome ACP and resume already consume. `failTurn` sets the reason
directly (no separate session `error` event). `agent/error` + logging are
unchanged for live diagnostics.
- No format-version bump: pre-release, no persisted data, so per the format
policy there is nothing to migrate or reject (the RFC's "refresh the format
version" criterion over-reached). `version` stays 1.
- ACP fixtures + goldens re-recorded (keyless replay): dropped standalone
usage/error lines, usage folded onto assistant/message, error step on
turn/end.reason.
RFC moved proposed -> implemented with an implementation note recording the two
scope refinements.
Master's "fix(acp): align prompt and workspace contracts" changed the editor-
facing transcript — `user/message` → `user_message_chunk` is now emitted during
session/load replay ONLY, not live streaming, so a live prompt no longer echoes
the user message back. The snapshot tier caught this (6 goldens shifted); this
re-records the four recorded scenarios against the API and re-accepts the two
authored goldens so they reflect the merged behavior. Full suite green and
deterministic; this is the tier working as designed.
The goldens now mirror the shape of the surfaces they capture — one compact
JSON record per line — matching the wire (NDJSON stdout) and disk (JSONL
session log) formats, renamed *.golden.jsonl. They stay grep/jq-able and
faithful to what the agent emits, where the prior pretty-printed .txt was a
reformatted representation. Both normalizers drop the 2-space indent; the
normalizer spec asserts the compact form. All 11 goldens regenerated; replay
remains deterministic (8/8 across runs).
Adds the first cut of snapshot scenarios, each asserting a normalized stdout
transcript golden and (for model turns) a re-persisted session-log golden:
- text-turn, tool-call-turn, multi-turn: RECORDED against the real API — the
committed session.jsonl is a genuine harvested log; replay derives the model
script from it and reproduces deterministically with no key. tool-call-turn
exercises the real bash executor (echo SNAPSHOT_OK → tool/call + tool/result
+ a post-tool answer step).
- error-finish, cancel: AUTHORED via a replay.override.json sidecar (the live
API can't be coaxed into a deterministic 401 or mid-stream cancel). error-
finish replays a {kind:throw} 401 → the bridge answers the prompt with a
JSON-RPC error and the log records turn/end{kind:error}; cancel replays a
{kind:hang} → stopReason:cancelled.
Two input-DSL ops support these: promptExpectError (awaits the prompt, asserts
it rejects — the editor's view of a failed turn — and swallows it) and
promptAndCancel (dispatches the prompt unawaited, waits until the client
OBSERVES the streamed agent_message_chunk, then cancels — pinning frame order
so the cancel transcript is deterministic; fixes a flake Codex caught where the
late chunk and the cancelled response could interleave either way).
Scenarios carry a `recorded` flag so test:snapshot:record only re-runs the
live-API ones. reasoning/max-tokens scenarios are deferred (hard to force
deterministically from the live model). Per docs/rfc/implemented/2026-06-19.
