Drain idle injection flushes before agent teardown, snapshot approval and subagent provider inputs, and gate subagent lifecycle events on real child readiness. Align the RFCs and generated contracts with the hardened behavior.
Master brought 50 commits (the tool-cordis group, dsh-code-runtime + worker,
the tools/execute around-dispatch seam + timeout-policy, repeat-tool-guard,
agent/session-prefix, the ui reorganization). Beyond the ten textual
conflicts, the merge reconciles master's new seams with this branch's
scoped-registration world:
- tools/execute (new waterfall around core dispatch): dispatched with the
SAME exec.agent carrier as the pre/post waterfalls — an agent.ctx wrapper
times/retries only its own agent's calls — and its base thunk resolves the
tool through the caller's visible view (get(exec.name, exec.agent)), so a
scoped/shadowed tool dispatches and a restricted-away global stays
UNKNOWN_TOOL. Declared this: Scoped<ToolRegistry> with the scope-filtered
doc sentence; invariants table + verify-scoped-dispatch pin it (21 events).
- agent/session-prefix (new waterfall, once per loop instance): composed via
the fused agentEvents dispatcher (scope-filtered like every agent-subject
event), declared this: Scoped<Agent>, table-pinned. agent/pre-step keeps
master's new sessionPrefix parameter with this branch's Scoped this.
- timeout-policy reads the budget through the caller's visible view
(get(exec.name, exec.agent)): a scoped tool's own timeoutMs governs its
calls; a global name-twin's budget is never misapplied to a shadowing
per-agent variant.
- tool-cordis: cordis_inspect's tools section lists the CALLING agent's view
(its description promises "what you can call"); the sandbox tool façade's
reads resolve through the mount's own scope, mirroring where its register
lands writes; sandboxRegisterTool's return type carries the exact-disposer
union honestly. dsh-scope declared as peer+dev with the project reference.
- doc-sync chain unions master's verify-cordis-api with this branch's
verify-scoped-dispatch; the generated catalogs, event matrix (the
zero-dispatcher guard passes over master's new events), module graph, and
the cordis api-catalog are regenerated on the merged surface.
Full gate sequence green on the merged tree: typecheck, lint, per-file 100%
coverage (2668 tests), snapshots (38), doc-sync, module graph, build,
hygiene, demo smoke.
Every live agent owns a dsh-scope context (Agent.ctx, key = the agent),
minted inside the loop's composite lifecycle effect: registrations through
it are agent-visible and agent-lifetime, and agent.ctx listeners hear only
that agent's dispatches. The composite yields the scope's raw disposer
first (identity-nested, no un-nested window), then session entry (scoped
enter captures the session carrier), then registration; teardown runs
stop/drain -> unregister -> detach session -> unwind scope, keeping
store/registry rollback synchronous on every failure path.
CreateAgentOptions.setup(agentCtx) runs after the scope is minted and the
agent registered, before agent/session-start and the loop start — the slot
where a creator composes the agent's scoped world (persona sections,
restrict(), scoped tools); a throwing setup unwinds inside the rollback
boundary. Setup registers, it never drives.
agentEvents(ctx, agent) fuses the scope carrier with the injected subject
argument for every agent/* dispatch (the correct dispatch is the shortest
spelling); assembleContextFor(agent) pairs the agent DX field with the
scope layer selector. All loop/agent/registry dispatch sites converted;
agent/* event declarations carry this: Scoped<Agent>; ctx.agent is a safe
root accessor defaulting undefined, shadowed by each agent context.
A cancel/dispose landing inside the first agent/session-prefix waterfall
used to commit the listener chain's return value to the instance cache
before the interruption check dropped the turn; an abort-aware listener's
degraded fallback would then ship on every later request of the instance.
The commit now happens only after the composition survives the
interruption check — the cache only ever holds a fully composed prefix,
and the next turn recomposes under a live signal.
ds-review-bot critical (follow-up): on the first step of a resumed or
seeded/forked instance, auto-compaction ran before runStep composed
this instance's prefix, so the gate read the PREVIOUS instance's logged
prefix from the header fold — a contributor that grew across
resume/fork (skills added, AGENTS.md grown: exactly the
environment-dependent case) could under-gate and ship an over-window
first request.
The loop now composes agent/session-prefix before the instance's first
agent/pre-step (still once per instance; runStep just reads the cache),
and agent/pre-step carries the composed prefix to its listeners.
CompactService.compactIfNeeded gains the sessionPrefix parameter;
BasicCompactService.estimatePressure gates on the handed value — the
header-fold read is gone, so the estimate is exact at every step
including a resumed/forked instance's first. Composition moving before
the boundary snapshot also means a composing listener's session append
now joins the CURRENT request (documented on the seam).
New coverage: composition precedes pre-step and the seam receives the
composed prefix; cancel and disposal landing inside the composition
window drop the step cleanly; the compact gate test hands the prefix
directly.
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.
Tianyi Cui
Dudu-0223
Hypatia May
Yichen Jiang