The agent-scope-contexts RFC (implemented) records the decision tree:
the dsh-scope primitive over cordis extend/Context.filter/no-op fibers,
two-level flat scope with shadowing, restriction/grant semantics, the
scoped-dispatch rule with fused helpers, the setup window, and the
alternatives (explicit scope params, isolate, event-filtering-only,
vendored support) with why each lost. CONTEXT.md pins the glossary.
architecture.md gains the Agent Scope section, the dsh-scope spine row,
the scoped turn-flow line, and an extension-table row (ceiling 1640→1790:
the two-layer registration model is a new architectural axis; additions
are condensed to pointers). READMEs of every touched package re-state
their scoped facts; the stale structured-runtime README section is
replaced by the scoped-registration description.
scopeHost(ctx, services) is the sanctioned way to mint scopes in tests: it
names absent services loudly instead of the cryptic cordis without-inject
dead end, and catches the silent-no-op host (cordis resolves a
dependency-pending fiber's await without running the inject callback).
The ACP ToolPresenter resolves presentations through the session agent's
view (tools.get(name, agent)) so a scoped/shadowed tool renders with the
same definition that executed.
verify-scoped-dispatch (doc-sync + pre-push) pins the dev-invariants
carrier table against the declaration JSDoc set: an event enforced but
undocumented, documented but unenforced, or a registry-subject notification
leaking into the table fails the build. subagent/start|end docs gain their
scoped-dispatch sentence (a real gap the gate caught on first run).
Three dev-mode invariants close the leak-by-default regression class at
runtime: (1) every scope-filtered event family must dispatch with a scope
carrier — a bare dispatch throws at the call site naming the carrier rule;
(2) where the subject is recoverable from the arguments (agent/*, the tool
pipeline, prompt assembly) the carrier's key must BE that subject, and an
assembly context must never carry agent without scope (use
assembleContextFor); (3) a turn/start logged before the owning agent's
agent/session-start is the setup-drives teaching error (setup registers the
scoped world, it never drives the agent).
SubagentStartRequest gains persona (capability-gated like toolFilter); the
in-process driver composes the child's scoped world in the factory's setup
window — persona as a scoped shadowing deployment:persona section,
toolFilter as a scoped tools.restrict() (loud unknown-name validation),
outputSchema as the scoped structured runtime. spawn/fork now advertise
every start-time capability; ACP stays all-false. A parent-scope teardown
effect links each child to its parent through the memoized handle, so a
disposed parent reaches its whole subtree even if the delegating tool's
finally never runs; subagent/start|end dispatch in the delegating parent's
scope.
structured.ts loses the placeholder schema, the final-assembly swap/strip,
the refcounted root runtime, and the WeakMap state: each child registers
its OWN capture tool (real schema), instruction section, and enforcement
listeners on child.ctx, riding the child's fiber. The commit listener is
call-keyed (a stale stage from a short-circuited post-execute chain is
dropped, never promoted on a later call), and one scoped prepend re-assert
listener preserves the final-assembly guarantee against a stripping global
listener.
tool-subagent gains persona/toolFilter/maxDepth passthrough config —
deny-listing the delegation tool (or maxDepth) is how a deployment bounds
recursion; the omitted-toolFilter schema key is forced absent (a
materialized {} would mean an empty allow-list, i.e. deny-everything).
The producer/consumer matrix reads dispatch sites statically; the fused
agentEvents dispatcher, the agent's loopCtx handle, the session store's
captured emitCtx, and carrier-first argument lists were invisible to it,
silently dropping agent-loop/session as producers of every scoped event.
The generator now recognizes those spellings; the Agent type-equiv doc
block gains readonly ctx.
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.
dsh-tools and dsh-system-prompt gain a per-scope registration layer over
dsh-scope: a registration through a scoped context files into that scope,
shadows a same-named global contribution for that scope (per-agent persona
and tool variants), and unwinds with the scope. tools.restrict() masks the
global surface per scope (snapshot-at-registration, loud unknown-name
validation, intersection composition; scoped grants bypass). One visibility
function feeds schemas/get/execute, so prompt, presentation, and dispatch
can never disagree; out-of-view executes as UNKNOWN_TOOL.
Prompt tool providers now receive the AssembleContext and return
{schemas, knownNames}: toolOrder validates against the pre-restriction name
universe (a typo fails every assembly loudly) while ordering operates on
the post-restriction schemas (a restricted-away tool is a normal absence).
dsh-session captures each session's dispatch carrier at enter() from the
entering context's scope tag, and the new sessions.flush(session) owns the
awaited session/flush dispatch. tools/pre|post-execute and
system-prompt/assemble dispatch with scope carriers keyed by their subject;
session/created|event|flush by the owning session's scope.
The seam shipped without its own RFC — the reconstructable-requests RFC
was amended with the mechanics, but the decision record (why a
compose-once frozen prefix, and what the per-request before/after shape,
a system-prompt section, a durable history opener, per-turn composition,
and a dedicated session event each lost to) had no home. Implemented
lifecycle, feature class, dated to the first commit of the work.
A reviewer read "TypeScript via host-side type-strip" and reasonably
asked what typing buys if nothing checks it — the group README never
said the annotations are advisory by design. The row now states it; the
rationale stays in the RFC and the enforcement story (per-dispatch
validateArgs) in the dsh-tools README.
createScope(ctx, key) mints a tagged context over a synchronously-usable
no-op-plugin fiber (one fact drives visibility AND lifetime); scopeOf reads
the tag through the prototype chain; scopeTarget(base, key) builds the
scope-filtered dispatch carrier over cordis Context.filter, composing the
base's own filter, branded Scoped<T> and runtime-marked for the dev
invariants. Scope.rawDispose exposes the exact cordis disposer so a
composite effect can nest the scope's teardown at its yield position.
- spill-policy validates maxInlineBytes as a non-negative integer at LOAD, so a
bad config fails the deployment instead of letting a negative value reach
TextRetainer and turn every oversized-result call into an isError.
- Document the spill seam vocabulary in docs/core-data-structures/spill.md
(SaveTextSpill/SpillOwner/SpillSource/SpillRef/SpillPath, verbatim + type-equiv
gated) and index it from core.md, matching the other capability seams.
The seam gained sessionPrefix between fullSystemPrompt and signal in
18d478bc, but the compact README member table and the compaction
core-data-structures page still showed the 3-arg form and listed only
agent/system/signal as what pre-step supplies. The generated service
catalog was already correct; only these two prose homes drifted.
[P1] review finding: the run-scoped abort + queue drain ran only after
runtime.run() FULFILLED, so a backend that starts a binding call and
then throws left the sub-dispatch running past run_code's settlement —
its tool/code-dispatch event could append after the parent call
returned, breaking the drain-before-return contract. The quiescence
pair now lives in a finally around runtime.run(); the folded queue tail
keeps the drain from masking the thrown error. Pinned by a test whose
fake runtime fails mid-flight: pre-fix it returns in milliseconds with
the slow tool still running.
Two [P1] review findings on the worker runtime:
- maxValueBytes gated and sliced the rendered fallback by UTF-16 code
units, so a multibyte string ("€€€€" under a 4-byte cap) crossed whole
and a truncated multibyte rendering could still run ~3x over budget.
New truncateUtf8Bytes cuts at code-point boundaries under a real byte
budget; prepareValue's fallback and the host's forged-error-text bound
both use it, and the VALUE_RENDER_SLACK comment drops its now-obsolete
"sliced by characters" wrinkle.
- The patched stream write dropped Node's optional encoding/callback
arguments, so a program awaiting flush completion
(write(chunk, resolve)) hung to the wall ceiling and misreported as a
timeout. The shim now fires the callback asynchronously once the chunk
is admitted — including for writes the exhausted budget drops.
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.
Oversized plain-text tool results now spill to a session-scoped file and
return a bounded preview plus the spill path, so a verbose result stays
readable via `read` without consuming the next model request in full.
- dsh-spill: minimal SpillFiles seam (saveText → session-scoped SpillPath)
- dsh-spill-local: private 0700 session dirs, traversal-safe names, exclusive
owner-only writes
- dsh-spill-policy: tools/post-execute transformer; no-op unless maxInlineBytes
is set; skips read; best-effort on save failure (never turns a success into
an isError)
web_fetch is the showcase — no tool-specific spill code. The coding-agent
example loads the stack so its keyless Loader smoke guards the namespace-plugin
export shape. Snapshot gap for a transcript-visible web_fetch spill is recorded
in the RFC's Consequences (ACP replay is keyless and cannot hit the web).
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.
Verifies the namespace plugin has no default export and preserves
name/inject/Config through Loader.unwrapExports — the same guard
pattern as dsh-tool-web, per the packages/AGENTS.md convention.
Prove the full MCP protocol flow works end-to-end against real servers:
- Self-written fixture server: tool discovery, execution, error handling,
image placeholder, toolPrefix, and clean disposal
- @modelcontextprotocol/server-everything: echo, get-sum, get-tiny-image
- @modelcontextprotocol/server-filesystem: write_file + read_file round-trip,
list_directory with world-verification
All 15 tests keyless and deterministic (no API key needed).
Connects to an external MCP server and registers its tools on
ctx.tools. Supports stdio (child process) and Streamable HTTP
transports. Credential-shaped env vars are scrubbed before forwarding
to child processes.
- Plugin lifecycle: connect, sync tools, re-sync on ToolListChanged,
dispose unregisters and closes
- Full JSDoc on all exports (@param/@returns on functions)
- 100% per-file coverage (apply lifecycle, args coercion, env scrubbing)
- Config catalog regenerated
The seam's structured-clone boundary admits values JSON does not (BigInt,
Map, circulars), while tool/code-dispatch events must be JSON-appendable —
left unhandled, a sub-call could execute and then fail at logging time.
The bridge now JSON-normalizes binding arguments BEFORE dispatch (a value
that does not survive rejects that one call), so the dispatched form and
the logged form are the same JSON value by construction.
Adds the missing core-data-structures coverage the catalog policy
requires for non-spine seam vocabulary: the code-runtime.md sub-page
with drift-checked type-equiv blocks for all six seam types, the core.md
sub-page row, the type-equiv manifest entries, and LINK_MAP entries so
the generated service signature links CodeRunRequest/CodeRunResult;
cordis/config catalogs regenerated.
New group packages/code-runtime/ with the interface package
@deepseek-ai/dsh-code-runtime, per the Code Mode RFC: abstract CodeRuntime
service (run() resolves program failures as an error field, rejects only
for seam misuse), the CodeRunRequest/CodeBindingNamespace/CodeRunResult/
CodeLogEntry/CodeRunFailure vocabulary, and readonly language/isolation
backend descriptors. Registered in the tsconfig maps, packages/README,
architecture service map, and the doc-graph service-role classification;
catalogs regenerated.
The RFC's one forward path token to the worker package becomes an npm-name
mention until PR3 creates that directory (verify-package-paths is
drift-scoped: the now-existing group made the token checkable).
docs/architecture.md ceiling 1630 -> 1640: the doc gained a genuinely new
capability-service row; the row itself is already minimal.
Budget expiry terminated the worker but nothing cancelled an in-flight
host-side sub-dispatch, and a late dispatch could append events after
run_code returned. The bridge now owns a run-scoped AbortController
(follows exec.signal; fired on any run settlement), sub-dispatches get
the run signal, and run_code returns only after the dispatch queue
drains — no post-settlement appends, per dispose-to-quiescence.
(A1) Scope the wire-collapse guarantee honestly: systemPrompt.tools() is
a public multi-provider API, so the mode governs the registry's
contribution (the only shipped source); deliberate extra providers own
what they add, and the shipped-configuration invariant is test-pinned.
(A2) Replace pause-on-pending-RPC timeout with two independent budgets:
computeMs metered by worker.performance.eventLoopUtilization() busy time
(unfoolable by an un-awaited decoy dispatch; probe-verified) plus a
never-pausing maxWallMs ceiling.
(A3) Specify sub-call additionalContext as deliberately suppressed in
the MVP (immediate inject would break call/result adjacency; the plural
channel is named follow-up work).
(B) Orphan-process caveat vs bash-local's group kill; null-prototype
binding namespaces (__proto__/constructor names); per-PR doc artifacts
(packages/README row, architecture service map in PR2, config/tool/
persistence catalogs per owning PR); engines range corrected to
^22.19.0 || >=24.0.0.
Research finding: a SessionEventMap member is a log event — JSDoc prose
required, @mode is a hard error there, and docs/persistence-catalog.md
must be regenerated (todo/write is the log-only precedent). PR4's plan
now names both.
Own adversarial pass finding: a static inject on the registry would gate
ctx.tools (and every tool plugin) on a code runtime existing even under
mode 'native'. The RFC now names the sanctioned pattern: soft
ctx.get('codeRuntime') at use time (the agent-loop sessionPersistence
precedent) with absence failing loud in the provider thunk.
Supersedes the add-on-plugin + node:vm-stub draft in place (still proposed/):
code mode becomes a first-class ToolRegistry presentation mode
('native' | 'code' | 'both'), execution goes behind a new ctx.codeRuntime
capability seam whose shipped backend is one fresh Node worker thread per
run (type-strip, empty env, resource limits, hard terminate), at
bash-equivalent trust with no unsafe-flag ceremony. Renames the file to
2026-06-15-code-mode.md and regenerates the RFC index.
ds-review-bot critical: compactIfNeeded estimated pressure from the
derived history + system prompt only, but every loop-built request also
carries EpochHeader.messagePrefix in front of the history — a
deployment at the window edge would under-estimate by exactly the
prefix, skip compaction, and ship an over-window request.
BasicCompactService now gates on estimatePressure(): the session prefix
read from the log's folded header + the derived history + the system
prompt. The fold is exact from the instance's second request on (and
from a resumed instance's first — the previous instance logged its
prefix); it is absent only before a fresh session's first request,
where the history is a single prompt and compaction is moot. Compaction
itself still shrinks history only — a prefix that alone approaches the
window is a configuration error no compactor fixes, same as the
documented single-unit-overflow stance.
The credential env scrub (SENSITIVE_ENV_PATTERN/buildChildEnv), the
spawn-failure capture (spawnFailure), the child-exit waits
(waitForExit/exitsWithin), and the stdin-EOF -> SIGTERM -> SIGKILL dispose
ladder move out of subagent-acp into a new pure library package (the
subagent-inprocess shape), with the ladder taking its two grace periods as
parameters — defaults stay in the plugin Config. New isolated-config-dir
helpers (mkdtemp create, best-effort remove; a pinned dir is never removed)
land alongside for the CLAUDE_CONFIG_DIR / CODEX_HOME redirection the RFC
names.
The ACP backend migrates onto the library with no semantic change: its suite
passes with import-path edits only. bash-local keeps its sibling copy, per
the RFC's blast-radius call.
RFC: docs/rfc/proposed/feature/2026-07-07-claude-code-and-codex-subagent-backends.md
Tianyi Cui
Yichen Jiang
Dudu-0223
Wenlu Wang
TianleLin
lintianle
pku-xht