Conflicts: the four generated catalog docs (regenerated over merged sources),
session index.ts exports (keep chunk-rows exports + master's SessionSurface
re-export), stdio/acp demo config schema and persistence wiring (thread
packChunks through master's DEFAULT_PERSISTENCE_ROOT/UI shape), stdio README
config table, and the jsonl spec import line. The packed-chunk fixture also
gains the provenance field master made required on assistant/message.
toolPairingBalancedAfter previously answered by resolving a cached
positional successor and reading its before-balance, with a null-successor
depth fallback. Both queries are the same prefix property sampled at
adjacent cuts, so the cache now holds one per-cut balance sequence
(N nodes -> N+1 cuts) plus a seq->position index; before/after differ
only by a cut offset. The successor map, the duplicate rebuild/extend
fold loops, and the non-null assertion are gone, and the running counter
is named inProgressToolCalls. Docs describing the successor mechanism
are updated in place.
Providers stream token-sized deltas, so a session log stores hundreds of
near-identical assistant/chunk lines whose JSON envelopes dwarf their
payloads (~56x measured on a real DeepSeek session, 73% of file bytes).
Add a lossless storage codec to dsh-session: packChunkRuns() folds each
run of >=3 consecutive same-block delta chunks into one storage row --
text-chunks / reasoning-chunks / tool-call-chunks, bare slash-less tags
like the header line's 'session' so rows cannot be confused with session
events -- and decodeStorageRecord() expands rows back to the exact
original events (seq0/time0 + dt gap array reconstruct every member's
seq/time; tool-call rows carry the run-constant id/name). The encoder
whitelists exact shapes and stores anything unrecognized verbatim; the
decoder validates row-tagged values and fails loud on malformation.
The JSONL backend gains a packChunks config (default false). Writing
packs only when enabled -- default-off output stays byte-identical to
the previous layout, so snapshot goldens are untouched. Reading is
layout-blind: scanLog always decodes rows and now checks seq contiguity
with a cursor instead of the line index, so packed, unpacked, and mixed
files all load identically. Fixture readers (llm-replay parseSessionLog,
acp-snapshot normalizeSessionLog) share the codec; the normalizer zeroes
a row's time0/dt exactly like an event's time. The two demo bundles
plumb packChunks from cordis.yml to the backend.
Measured on a real coding session: 105 KB -> 42 KB (-60%), 475 lines ->
74, with reasoning/tool-call heavy sessions saving the most. Covered by
example + fast-check round-trip codec tests, backend packed/mixed/torn-
tail specs, and an end-to-end demo run loading a packed log through a
default-config backend.
Review discussion converged on the industry shape (Claude Code caches
user context per conversation; Codex separates initial context from
diffs; Kimi appends at continuation boundaries to protect prompt
caching): stable openers belong in a compose-once prefix, mid-session
changes belong in append-only history — not in a per-request slot.
agent/session-prefix fires ONCE per loop instance, lazily on its first
request-building step: the composed Message[] is deep-frozen, cached on
the transmission bookkeeping, recorded as EpochHeader.messagePrefix on
the anchoring 'initial'/'resume' snapshot, and reused verbatim for
every request the instance sends — prefix stability is structural, not
a producer discipline, and a resume recomposes with attributable drift.
The request is messagePrefix + boundary snapshot.
The per-step RequestAdvice/RequestAdviceContext surface and the
messageSuffix header field are dropped: the tail slot had no consumer,
and every current update pattern (new AGENTS.md discovered, memory
update, skills change) routes through the existing append-only history
channels — inject(), tools/post-execute additionalContext,
prompt-submit additionalContext — each paid once and prefix-cached
thereafter. The messagePrefix delta arm stays for codec totality; the
loop never produces one in practice.
tianyicui's review: the seam name did not say what the event or its
types do. 'advice' reads both ways — advisory content for the model,
and AOP before/after advice woven around a join point (here the
derived history) without modifying it — so RequestAdvice.before/after
are self-describing. Types follow: RequestAdvice / RequestAdviceContext;
the logged EpochHeader fields keep their positional names
(messagePrefix/messageSuffix).
Also sharpens the core.md wording the review flagged as ambiguous:
before-advice sits in front of the ENTIRE derived history, directly
after the system slot (the conventional home for session-stable openers
— an AGENTS.md digest, a skills catalog), after-advice follows the
history's last message. Catalogs and doc graphs regenerated.
A new waterfall near request construction lets plugins contribute
request-ONLY messages framing the derived history: RequestMessages
{ before, after } with a frozen empty seed, fired inside the open step
after the agent/request config waterfall, so the step/start boundary
snapshot and its same-sync-frame invariant are untouched. The request
becomes messagePrefix + boundary snapshot + messageSuffix.
Contributions never enter session history — deriveMessages() is
unchanged — so the request header is their durable record:
EpochHeader gains messagePrefix/messageSuffix (canonical absence for
empty arrays), request/header-delta replaces either array whole with
an empty array encoding the transition back to absence, and the
dev-mode reconstruction cross-check now expects the folded header's
framing around the boundary derivation.
This is the seam for per-request advisory context that must be
model-visible now without becoming durable history (a skills catalog,
an environment reminder), keeping the base system prompt
workspace-independent and provider prefix caches stable. The docs
carry the channel cost model: session-frozen content belongs in
before, low-frequency change notices belong in durable history via
inject() (paid once, prefix-cached thereafter), and after is reserved
for small frequently-refreshed state snapshots re-paid on every
request they ride. No shipped producer yet, so ACP snapshot fixtures
are byte-identical.
A directory holding exactly one file adds a path level for nothing;
cordis-catalog/ keeps its folder because it holds two sibling pages
(events.md + services.md), matching config-catalog.md which was born flat.
docs/tool-catalog/tools.md -> docs/tool-catalog.md and
docs/persistence-catalog/log-events.md -> docs/persistence-catalog.md; their
generators' OUT paths and in-page relative links drop one directory level,
and every citation repo-wide (docs, RFCs, package READMEs, generator
headers) is updated. graph-atlas.md, config-catalog.md, and the doc graphs
regenerate with the new paths.
deriveMessages() no longer re-derives and re-clones the whole surface
per call: each node is projected exactly once, when first seen (O(new
nodes) per access), through the now-public deriveEventMessage — the
per-node pure function external reconstructors and the dev invariant
fold over a log prefix, so no two paths can disagree about a request's
messages. A surface rewrite (replace, invalidate) rebuilds, signalled
by SurfaceManager.replaceGeneration — monotonic, bumped by every folded
replace and by invalidate(), never reset. Callers get a fresh array
snapshot per call over SHARED deep-frozen messages: isolation of the
append-only log moves from per-call cloning to unrepresentability
(mutation throws), which the two isolation tests now pin directly.
Every conversation request's non-content half (system prompt, tool
schemas, call config — the EpochHeader) is now recorded in the session
log: a 'request/header' full snapshot (reason 'initial' | 'resume' |
'fallback') anchors the fold at conversation birth and process
boundaries, and 'request/header-delta' events (system line-trim,
name-keyed tools delta, whole config) encode mid-run changes. The pure
trio — foldRequestHeader / diffHeader / applyHeaderDelta — reconstructs
the header any request was built under from the log alone; the writer
contract round-trip-verifies every delta with a 'fallback' snapshot
when the encoding cannot express a change (pure tool reordering), so a
well-formed log always folds cleanly. Canonical absence: empty system
and empty tools normalize to absent fields, matching request builds.
Persistence and cordis catalogs regenerated; SessionEventMap paste and
EpochHeader added to the core-data-structures session page.
docs/persistence-catalog/log-events.md enumerates every SessionEventMap
member — the owning dsh-session vocabulary plus the dsh-compact and
dsh-hook-protocol declaration merges — with payload, surface/log-only badge,
JSDoc prose, and declaration site. scripts/gen-persistence-catalog.ts is a
pure AST pass in the gen-cordis-catalog mold: verify-persistence-catalog
(--check) joins doc-sync, so a stale committed catalog fails pre-push and CI.
The walk enforces JSDoc completeness (every member needs description prose;
@mode is rejected as a category error — log events do not dispatch on the
cordis bus), derives the surface badge from the SurfaceEventType union with a
stale-member cross-check, and hard-errors on duplicate declarations. Payloads
render through the TypeScript printer so newline-separated multi-line type
literals still emit valid one-line fragments.
Documented the five previously JSDoc-less core events (turn/step boundaries,
tool/call), removed the two stray @mode tags on the hook/* merges, and
replaced the hand-restated event enumerations (session.md hook/* table,
compact README table, hook-protocol README bullets, session README name-list
— whose merge note had already drifted) with links to the catalog. RFC:
docs/rfc/implemented/process/2026-07-04-persistence-log-catalog.md.
The vocabulary maps grow by declaration merging, and the admission policy
stated on TurnEndReasonMap is that a variant lands with its first emitter.
Three declared items had no producer and no consumer:
- CacheHint and the cache?: CacheHint fields on TextBlock/ToolResultBlock:
nothing constructs a block with cache:, and neither adapter reads .cache —
DeepSeek prompt caching is automatic (hints map OUT of responses, never IN).
- MessageSourceMap.agent: zero constructors; the subagent backends send the
parent prompt with no source (logs as user), and the envelope renderer
interpolates source.kind without routing on it.
- TurnTriggerMap.continuation: the loop structurally cannot emit it —
continuation is further steps within a turn, never a new turn — and its only
writer was an llm-replay test fixture that needed any non-message trigger
(now an injection trigger).
Each variant returns the day it gains a real producer, via the same
merge-extensible maps. Docs updated in the same change: the MessageSourceMap
paste in core.md, the TurnTriggerMap paste in session.md (manifest untouched —
both symbols survive), the content-block vocabulary RFC's cache-hints
consequence line, and the RFC moved to implemented/ and amended to shipped
reality (the image block's own cache field had already left with the
drop-image RFC).
- session.md § TurnEndReasonMap now carries the full precedence rule
the old architecture.md stated and the loop implements (loop.ts's
stepFinishReason carry-forward): max-tokens wins over completed only;
disposed/aborted/error take precedence. The architecture.md pointer
was otherwise citing an incomplete home.
- The cookbook feature-map compaction row no longer reads as if a
model-facing /compact tool ships: a manual trigger invokes the same
ctx.compact routine; the consumer tool is deferred per the
compaction RFC.
Address the applied-hunk-diffs review:
- CRLF write overwrite emitted bogus every-line-changed hunks: write's
`before` was LF-normalized but `after` kept the raw model content, so a
CRLF rewrite of an LF file diffed every line. Normalize write's `after`
to LF so both sides share the diff basis (edit already did). Regression
test proves it fails on the raw-after path.
- The tool-private `meta` payload is now typed `unknown` (opaque) at every
seam instead of `JsonValue`. This drops the `dsh-tools -> dsh-session`
package edge that existed only to name the type, and removes the
`FileDiff` index signature that had been widening the type solely for
JsonValue-assignability. Serializability is still enforced at runtime by
`Session.append`'s isJsonValue check, which was always the real guard.
- Sync the docs the new result/meta surface left stale: ToolResultView's
diff card + ToolExecutionResult.meta in tools.md/session.md type-equiv
blocks, the acp/tools READMEs, and the adding-a-tool cookbook; regenerate
the cordis catalog and module graph.
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.
kingwl
Tianyi Cui
Hypatia May
Yichen Jiang