Load both hook bridges in the ACP example (dsh-hooks-claude → ./hooks.json,
dsh-hooks-codex → ./codex-hooks.json) so the full-transcript snapshot tier can
exercise each dialect against the real app. An absent config file is a silent
no-op, so a scenario carries only the file it needs and the other bridge
vanishes — verified byte-identical against every pre-existing snapshot.
Add a scenario per hook point × its headline Decision outcome, both dialects:
UserPromptSubmit block (authored, keyless) + context-fold, PreToolUse deny/ask,
PostToolUse block/context, Stop force-continue. The mid-turn scenarios are
recorded against the real API with the hook active, so the model's reaction to
a denied/blocked/force-continued turn is part of the replayed transcript.
SessionStart and SubagentStart are deliberately excluded (detached best-effort
inject races the log position — a recorded golden fails 10/10 on its own
replay), as is SubagentStop (observe-only, zero transcript footprint — a golden
could never be proven to fail). Both stay on the bridges' unit coverage. See
docs/rfc/implemented/testing/2026-07-04-hook-snapshot-matrix.md.
A Write CREATE rendered its completed tool_call_update as the model-facing
result TEXT (`<path>…</path>…Created file`), which — because an ACP
tool_call_update.content REPLACES the call's content — clobbered the
new-file diff the pending call installed. So Zed showed the diff, then
replaced it with raw XML-ish text; only overwrite/edit looked right
(their result re-sends a diff).
write's presentResult now ALWAYS returns a diff card for a successful
write: the applied contextual hunk from `meta` when there is one
(overwrite), else an args-derived whole-file diff (`oldText: null`) for a
create or an unchanged-content overwrite. This matches claude-agent-acp,
where the create diff rides on the update and no result text replaces it.
An error still falls through to generic rendering so its message shows.
edit is unchanged (it always has a hunk; no whole-file fallback).
Re-recorded fs-write / fs-write-overwrite goldens; the create's completed
update is now a {type:'diff'} block, not the XML result text.
fs write/edit now emit a result-time contextual-diff tool_call_update
(the applied hunk with ±3 context lines, one hunk per replace_all site),
matching what claude-agent-acp sends and what makes an editor render the
change in place. The call-time snippet diff stays; the result hunk
supersedes it (ACP content-replace).
Mechanism:
- A persisted tool-private `meta` channel: execute may return
`{ content, meta }`; `meta` (JsonValue) rides on the tool/result event
and is handed back to presentResult, so the diff reproduces on replay
(event-sourced). JsonValue is now exported from dsh-session.
- The backend returns raw before/after text (storage facts) on
FsWriteOutcome/FsEditOutcome; the tool computes the hunk via the npm
`diff` package's structuredPatch. A create has no before → no result
diff; a failed/aborted mutation carries no meta.
- ToolResultView gains a DiffResultView; the bridge's result-side switch
renders it as {type:'diff'} content blocks.
RFC: docs/rfc/implemented/architecture/2026-07-02-result-time-applied-hunk-diffs.md
(justifies the npm `diff` runtime dep over vendoring and the meta channel);
the render-intent-union RFC's Non-goal is updated to record this shipped.
All fs snapshot goldens re-recorded; edit/overwrite gain the contextual
result diff, create/read/policy-reject unchanged in structure.
Replace the "bag of optional fields" tool-presentation types
(ToolCallPresentation / ToolResultPresentation / ToolTerminal) with a
card-tagged discriminated union — the standing FIXME(tool-presentation).
A tool declares one render intent per call/result and the ACP bridge
switches on `card`:
ToolCallView = generic | terminal | diff
ToolResultView = generic | terminal
The `diff` card is new: fs write/edit now emit an ACP {type:'diff'}
content block (an editor's inline diff), which the old shapes could not
express. The bridge also relativizes a file card's title against the
session cwd (mirroring claude-agent-acp's toDisplayPath) while keeping
locations/diff paths raw, and derives the no-capability fenced console
fallback from a terminal result's output. read gains the window-in-title
(`Read foo.txt (5 - 8)`) and an always-set location line, matching the
reference adapter field-for-field.
Migrates all three producer families (tool-fs, tool-bash, tool-todo) and
the sole consumer (the ACP bridge) together — the source does not compile
piecewise. Adds snapshot coverage for the terminal _meta path (a new
capability-advertising scenario) and re-records the fs goldens to show the
diff cards. Applied-hunk (result-time, context-line) diffs need a new
result/event shape and are a follow-up.
RFC: docs/rfc/implemented/architecture/2026-07-02-tool-render-intent-union.md
The fs-policy gate throws FS_NOT_OBSERVED when the model edits a file it
never read; that rejection surfaces as a failed tool_call_update, but no
snapshot pinned it — a regression that dropped or mis-rendered the failed
card would pass every gate. Record a scenario that edits a seeded file
without a preceding read: the edit is vetoed, the file stays unchanged on
disk, and the transcript shows the pending edit card followed by a
status:'failed' update carrying the policy error.
Five recorded ACP snapshot scenarios exercising read/write/edit end-to-end
through the real acp-agent subprocess, replayed keyless in CI:
- fs-read — read a seeded file (read tool + presentation + observed-state)
- fs-write — create a file (write, no prior version guard)
- fs-edit — read then literal-replace (read-before-edit authorization)
- fs-write-overwrite — read then rewrite (replaceIfVersion after a read)
- fs-read-window — read lines 5-8 with offset/limit (windowing + the offset
surfaced as the tool_call location line)
The goldens confirm the tools render with their new presentation — Read/Write/
Edit <path> titles, read/edit kinds, and `locations` (fs-read-window carries
`{path, line:5}`) — and that the prompts steered the model to the fs tools, not
bash (zero bash calls in any golden). Recorded against the real API, filtered to
the new scenarios so no existing fixture churned.
The two bridge plugins that run a user's existing Claude Code / Codex hook
config on the harness's typed interception seams, built on the shared
dsh-hook-protocol library. A bridge is a faithfulness adapter, not a power
tool: anything it does a native cordis plugin does more powerfully — the
bridge exists only to run UNMODIFIED external hooks.
- dsh-hooks-claude: CC dialect. Seven hook points (SessionStart,
UserPromptSubmit, PreToolUse, PostToolUse, Stop, SubagentStart,
SubagentStop), CC per-event stdin payloads, env + ${CLAUDE_PLUGIN_ROOT}/
${CLAUDE_PROJECT_DIR} substitution, literal-or-regex matcher.
- dsh-hooks-codex: Codex dialect — a deliberate subset. Five hook points,
always-regex matcher, snake_case payloads (turn_id/model, no trailing
newline), no env/substitution, block-only decisions.
Both map the neutral merged outcome onto the seam's typed Decision and stamp
an explicit {kind:'plugin'} source on injected context (so it is never
mislabeled as a user prompt). Config parse-failure is contained; only command
hooks run. updatedInput is logged+warned (input rewrite deferred); the Stop
loop-guard is deferred (TODO).
Tests: per-file 100% — config-parse unit branches + per-seam mappings
end-to-end through the REAL loop + REAL bash + REAL shell scripts (scripted
mock model only) + a real-Loader export-shape guard. A keyless ACP snapshot
scenario (hook-prompt-block) proves a UserPromptSubmit hook blocks a prompt
end-to-end (rejected turn -> ACP cancelled, hook/* events in the log); a
with-key e2e (hooks.e2e.ts) proves a PreToolUse hook blocks real bash
(verified on disk). The snapshot normalizer now scrubs hook/result.durationMs.
RFC: docs/rfc/implemented/feature/2026-06-30-hook-bridges.md
Record the `todo-plan` snapshot scenario: a real prompt drives the model to call
todo_write, and the golden captures the resulting `plan` sessionUpdate (three
entries, priority synthesized as medium, status 1:1) plus the persisted
todo/write event. Registered in SCENARIOS; replays deterministically keyless.
Add a with-key coding-agent e2e that verifies the WORLD — a real model call to
todo_write lands a todo/write event whose snapshot is a valid, one-in-progress
list — not the agent's self-report. Wire tool-todo into the e2e harness.
Reconciles the session-surface work (surfaceOp/sourceEventSeqs provenance as
the sole derivation path) with master's worktree-subagent series (fork-seed
boundary + out-of-process subagent backends).
Semantic reconciliations beyond the textual auto-merge:
- SQLite SCHEMA_VERSION: both sides bumped 2->3. Merged to a single v3 carrying
BOTH column families — master's seed_length on `sessions` and surface's
source_event_seqs/surface_op on `events`. writeRow + both INSERT sites bind
the full set; the schema doc lists all three added columns as the v2->v3 gap.
- agent-loop runStep request: master's `sessionId: session.id` and surface's
per-append surfaceOp/sourceEventSeqs coexist (different regions).
- Fork seed + surface: a fork seeds the child from the parent's LIVE events,
which now carry surfaceOp, so the child's surface rebuilds correctly. Verified
end-to-end — the subagent-fork replay recalls the inherited "SAFFRON" codeword
through the seeded prefix.
- Subagent snapshot fixtures (recorded pre-surface) re-enriched via KEYLESS
deterministic replay: only surfaceOp/sourceEventSeqs added onto existing
recorded lines (matched by seq), no recorded value changed. Not re-recorded
against the live API.
Gates: typecheck, test (1112), test:snapshot (14), doc-sync, lint, build,
hygiene all green.
The seed-boundary change made fork-child replay route correctly but shipped
with no recorded fork scenario — the seedLength slice was exercised only by
llm-replay unit tests and a persistence round-trip, never by the full-transcript
snapshot tier. Add two recorded scenarios that drive a real fork child through
it:
- subagent-fork: parent completes a turn, then forks one child (child fixture
carries a non-zero seedLength, the boundary the replay slice consumes).
- subagent-mixed: parent completes a turn, then delegates once via spawn
(seedLength 0) and once via fork (non-zero seedLength) in one transcript —
the first scenario to drive two subagent backends at once, exercising both
branches of the slice.
Both need a completed turn-1 so the fork seed is a non-empty completed-turn
prefix (a turn-1 fork seeds empty = spawn, which would not exercise the slice).
Removing the slice turns both scenarios red (the fork child receives the
parent's recorded chunks), proving the guard bites.
ACP (out-of-process) subagent replay remains a different shape, still tracked
as TODO(acp-subagent-replay).
Reconcile the session-surface feature with master's package reorg and
simplifications:
- Adopt master's folded usage (assistant/message.usage; standalone `usage`
event dropped) and re-attach surface metadata (surfaceOp/sourceEventSeqs).
- Add surface opts to master's new max-tokens assistant/message append.
- Port surface columns onto the coordinator-refactored SQLite backend at its
new path; drop the dead v1->v2 migration (bump-and-reject, no migration per
pre-release policy).
- Move the session-surface RFC into implemented/architecture/ and refresh its
stale body (no migration, SESSION_FORMAT_VERSION=0, renamed package paths).
- Update the core-data-structures catalog SessionEvent blocks for the two new
surface fields; regenerate the cordis catalog.
- Re-harvest ACP snapshot fixtures (keyless replay) to carry surface metadata.
The snapshot tier was built single-session: dsh-llm-replay served calls from
one global positional cursor, and the harness harvested one session log. A
subagent runs as a second agent with its own session, so a parent→child
scenario could neither replay deterministically nor harvest the child's log.
This resolves the TODO(subagent-snapshots) deferral from the subagent RFC.
- Stamp the calling session id onto the model request: GenerateOptions.sessionId
(typed Branded<'SessionId'> to avoid the dsh-llm↔dsh-session cycle), set by the
agent loop from agent.session.id. Adapters ignore it; an llm/stream listener
routes by it.
- Key replay per session: dsh-llm-replay loads the parent log plus one per child
(childFiles / $DSH_SNAPSHOT_CHILD_FILES), derives a script per recorded session,
and binds each live (freshly-random) session to a recorded script by first-call
order — parent first (earliest createdAt, first to stream). Keys by WHO calls,
so it survives a future concurrent/backgrounded subagent; a global cursor would
not. An unrecorded extra session fails loud.
- Harvest every log: the harness collects all .jsonl across cwd buckets, ordered
primary-first (top-level, then children by createdAt), and RunResult exposes the
plural sessionLogs. The spec writes each back on record (session.jsonl +
session.<n>.jsonl) and diffs each against its fixture on replay.
- Wire the subagent seam + spawn + fork + tool into the acp-agent example (both
cordis configs) and add two nested scenarios recorded against the real API:
subagent-spawn (parent + 1 child) and subagent-multi (parent + 2 children, 3
sessions). Both replay keyless in the default gate.
A new RFC documents the design (docs/rfc/implemented/testing/). Single-session
replay is unchanged (a call with no sessionId is one anonymous primary session).
TODO follow-up: a dedicated branded-ids package could own the SessionId brand and
dissolve the cross-package cycle note; out of scope for this testing PR.
Codex review of the trace-event fold found two merge-blockers.
Blocker #1 — format version. Folding usage onto assistant/message and removing
the standalone usage/error events changed the persisted SessionEventMap shape,
which per the AGENTS.md "bump the version and reject — don't migrate" policy
requires a backend to reject any non-current log. Centralize the version in an
exported SESSION_FORMAT_VERSION constant (dsh-session), read by both write sites
(Session constructor default, SessionStore.prepare header) and the coordinator's
load-time assertVersion check. The constant is pinned at 0: while unreleased the
on-disk format is unstable/pre-release, so breaking shape churn is absorbed at v0
(no monotonic bump until the first tagged release) and any non-0 log is rejected
on load — no migration. Update every test/fixture/doc that stamps a
currently-written header to the constant, bump the ACP snapshot fixture + golden
headers to v0, and keep the version-rejection test meaningful by switching its
bad value to a clearly non-current 99. AGENTS.md documents both the monotonic
(SQLite SCHEMA_VERSION) and pinned-0 (session log) pre-release stances.
Blocker #2 — restore the late turn-end warn. failTurn now sets the error reason
only while the turn is still open; once turn/end is appended (a throwing
agent/turn-end listener after closeTurn) the reason can no longer reach the
durable log, so the late throw is logged via ctx.logger.warn instead of
vanishing into a futile post-close assignment. A regression test asserts the
warn fires.
Also guard the normal-step assistant/message append with the same
content-or-usage condition as the max-tokens branch (a content-less, usage-less
step records no trace-only row), with a covering test.
Model-driving ACP snapshot scenarios shipped both session.jsonl (the
replay fixture) and session.golden.jsonl (the expected re-persisted log).
For recorded scenarios the normalized fixture and golden were byte-identical
— pure duplication. Remove session.golden.jsonl entirely: every model
scenario now has at most one committed session-log artifact, session.jsonl,
which doubles as the replay source AND the expected produced log.
The snapshot test compares the replay run's persisted log against the
session.jsonl fixture, normalizing BOTH sides — but each against its OWN
volatile values, not a shared context. A raw harvested fixture bakes in the
recording run's session id / cwd / timestamps, distinct from the live replay
run's; since normalizeSessionLog scrubs cwd by exact string match, the
fixture must be normalized against its own header (new fixtureContext helper)
or its stale recorded cwd would leak unscrubbed and the compare would fail.
The session side uses a normalized-string toEqual, NOT toMatchFileSnapshot,
so a run never overwrites the fixture.
Authored override scenarios (error-finish, cancel) now hold their expected
produced log in session.jsonl. Verified llm-replay ignores the fixture for
model chunks when an override exists: loadReplayScript() returns the override
array and never reads config.file, so committing the full expected log there
does not affect replay behavior.
The required-fixture guard is now per-kind: every scenario needs input.json +
stdout.golden.jsonl; model scenarios need session.jsonl; authored ones
additionally need replay.override.json. Updates the ACP-snapshot-tests RFC to
the reduced fixture set and moves the proposing RFC proposed -> implemented.
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" made session/new
reject a non-empty additionalDirectories / mcpServers (widening the workspace
scope is unimplemented). Add a `reject-extra-dirs` scenario + a
`newSessionExpectError` input op that pins this editor-facing contract: the
bridge answers with `-32602 Invalid params: additionalDirectories is not
supported`. Keyless, deterministic, no model call.
(session/load replay — the other new master behavior — needs a two-phase
seed-then-load harness and is left for a focused follow-up.)
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.
Establishes the standard way to give a snapshot scenario a non-empty starting
workspace: an optional `<scenario>/workspace/` directory whose contents the
harness copies into the temp cwd before the run (for both record and replay),
so the agent's bash tools see the seeded files. The cwd is normalized in the
goldens, so seeded paths stay stable.
The new `workspace-edit` scenario demonstrates the full read→write→verify cycle
on a seeded file: it ships `workspace/greeting.txt` ("hello"), prompts the agent
to append a WORLD line and cat it back. The recorded log captures the real bash
edits (`echo WORLD >> greeting.txt`, then `cat` showing `hello\nWORLD`), and it
replays deterministically with no key.
Also hardens runScenario teardown (Codex review): workspace seeding and spawn
now run inside the try whose finally removes both temp dirs, so a seeding/spawn
failure can't leak them. Documents the convention in the RFC + example README.
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.
Adds the snapshot-test harness and the keyless replay pipeline end-to-end.
- snapshot-harness.ts: boots the real acp-agent subprocess via the cordis
Loader (preserving TSX_TSCONFIG_PATH so unbuilt dsh-* imports resolve from a
temp cwd), tees raw stdout into an SDK ClientSideConnection, interprets a
per-scenario input.json DSL (initialize / newSession capturing the random
sessionId / prompt / cancel), closes stdin to trigger graceful shutdown, and
harvests the persisted session.jsonl. Failure-safe: a finally block SIGKILLs
a live child, awaits its exit, and removes both temp dirs even on a thrown
step or harvest. Raw bytes are buffered and decoded once (no multibyte split).
- snapshot-normalize.ts (+ spec): two pure normalizers (stdout frames + session
JSONL) scrub cwd, session ids / UUIDs, and JSON-RPC ids, and zero time /
createdAt — but keep `seq` (deterministic by contract). normalizeStdout throws
on a non-JSON line (the stdout-purity check).
- start.ts: selects cordis.snapshot.yml (replay, providerless) or
cordis.snapshot-record.yml (record, real adapter) from DSH_SNAPSHOT, skips
.env in replay, and disposes the ctx on stdin end so persistence flushes
before exit (harvest-after-flush, not on the prompt response).
- acp.snapshot.ts: asserts the normalized stdout golden (and, for model
scenarios, the re-persisted JSONL golden) via toMatchFileSnapshot; record mode
writes the harvested log back to the scenario fixture; an orphan-fixture guard
fails on an unregistered scenario dir.
- handshake scenario: initialize + session/new (no model call; a header-only
session.jsonl, since session/new persists no events).
- vitest.snapshot.config.ts, test:snapshot / test:snapshot:record scripts, a
pre-push snapshot job, and the knip entry.
Incorporates Codex review: record-fixture writeback, failure-safe teardown,
seq-not-scrubbed, harvest-after-flush. Per docs/rfc/implemented/2026-06-19.
Tianyi Cui
Hypatia May