The continuable path has no Task, so send_message reports a queued next turn
and continuable delegation returns only the durable child id. Pins that a
follow-up queues behind an open turn rather than steering it, and that a
non-parent caller is rejected.
Also makes startContinuable/followup reject rather than throw synchronously
when continuation services are absent, so callers have one failure mode.
Covers the inbox-acceptance return boundary, pre-acceptance rollback,
caller-signal ownership on both sides of acceptance, residency-only routing,
single-inbox FIFO ordering across parent and user origins, waiting wakeup with
a retained handle, cold resume without the historical parent, ownership
registration and release, child-first disposal, send-versus-dispose races,
durability failure without an ownership leak, per-epoch lifecycle pairing, and
the absence of cancellation, steering, and report surfaces.
Replace the Task-backed continuation manager with one durable Session plus at
most one process-local Activation — a residency epoch for a reconstructed child
Agent, not a request, result, cancellation, or Task boundary. The manager owns
activation admission, authority, the live ownership graph, cold resume, and
child-first disposal; the Agent inbox is the only turn FIFO.
- startContinuable() is async and returns { childId, messageId } at inbox
acceptance; followup() takes a SubagentAuthority and returns AgentMessageId.
- SubagentProvider.resume?(), SubagentProviderResumeRequest, SubagentRun.steer?(),
SubagentProviderStartRequest and SubagentContinuation are deleted;
prepareContinuable?() is the continuable-creation capability.
- Cold resume calls ctx.agents.resume() from the manager through a private
activation-owner scope, never dispatching through a provider.
- Extract shared child composition, descriptor seeding, depth accounting, and
one-shot run settlement so the manager and one-shot driver keep one home
per fact.
Tests and docs follow in subsequent commits.
- Strict steer now rejects the two windows where an acknowledged
message would be silently dropped: the closed-turn durability-flush
window (status still running, loop strands drained steering) and a
committed structured capture (terminal turn-stop discards late
steering). Seam JSDoc, catalog doc, README, and the Agent Note
bilingual pair state the tightened contract; new keyless tests pin
both rejections.
- Continuable background delegation now fails loud when the advertised
send_message tool is not registered, instead of starting a durable
child the model cannot continue. The acp-agent example already loads
the control tool; the tool-catalog boot recipe is unaffected because
capability wording is harvested at mount.
Implement the continuable background subagents RFC: a durable child
session with a series of Task-backed activations, each disposing its
run before the Task settles.
- dsh-subagent: rename SubagentRun.sendMessage to strict steer, drop
run-level resume, add SubagentProvider.resume dispatch via
SubagentService.resume, the continuation start field, and the
versioned model-hidden subagent/descriptor session event.
- dsh-subagent-inprocess/-spawn/-fork: publish the control-allocated
child id, append the descriptor inside the initial turn, implement
cold resume from the child's own transcript under the live parent
scope, and strict running-only steer.
- dsh-subagent-control (new): SubagentControlService owning stable
child ids, descriptor snapshot/fold/authorization, Task-backed
activation with settle-then-dispose ordering, the process-local
active-run association, and steer-or-resume sendMessage routing.
- dsh-tool-subagent: background route branches on the provider's
resume capability (continuable via the control service; one-shot
task for ACP), returning both child and task ids.
- dsh-tool-subagent-control (new): the globally named send_message
tool rendering steered/started routes.
Keyless coverage spans Task ownership and disposal ordering, running
delivery, cold follow-up, descriptor rejection and rollback, known-id
reconstruction, kill during lookup, admission races, and a new
subagent-continuable ACP snapshot scenario.
The group's convention is package suffix == provider default
(subagent-acp/'acp', subagent-spawn/'spawn', subagent-fork/'fork'), and the
provider default became dsh-sdk in the last review round — so the package
follows: @deepseek-ai/dsh-subagent-dsh-sdk at
packages/subagent/subagent-dsh-sdk, plugin name subagent-dsh-sdk,
diagnostics prefixed subagent-dsh-sdk:. The dsh echo has precedent
(dsh-llm-deepseek). Directory, fixture path, knip/tsconfig/examples
registrations, catalogs, READMEs (en+zh), and the Agent Note follow; the
sdk-client dispose ladder moves to its own module (src/dispose.ts) with the
deterministic FakeChild tier tests restored alongside it.
Master's #660 replaced dsh-subagent-subprocess with the dsh-subprocess
capability seam (ctx.subprocess + scrubbedParentEnv, tree-scoped teardown)
and moved subagent-acp onto it. Convergence for this branch's packages:
- The shared out-of-process provider vocabulary this branch had grown in
the deleted library (NO_START_CAPABILITIES, assertPositiveFinite, cwd
resolution, settleRunResult, subprocessRunHandle) moves into the subagent
seam package as out-of-process.ts — it enforces subagent-seam contracts,
not process mechanics, and both out-of-process backends now import it
from there (subagent-acp keeps master's shape otherwise).
- subagent-sdk spawns THROUGH the SDK client (the subprocess README's
documented exception for SDK-managed transports) and now applies the
seam's scrubbedParentEnv() + explicit-env merge in place of the deleted
buildChildEnv.
- sdk-client inlines the EOF→SIGTERM→SIGKILL ladder as private helpers (it
runs outside any harness context, so it cannot ride ctx.subprocess).
- The child harness fixture gains the now-required dsh-subprocess-local
entry for bash-local; the fixture cordis.yml keeps exercising the
shipped provider default.
SubagentStartRequest.parent, its core-data type-equiv mirror, and the
ACP backend Agent Note still said the out-of-process backend ignores
request.parent — no longer true: with cwd unconfigured it reads exactly
the session header's cwd, and a parent session without one now rejects
at start. State the one-field read at each owning contract, record the
workspace-resolution decision in the Agent Note, and align the README's
accessibility wording with the search-permission guard.
A subagent child's recursion depth lived only in runtime AgentOptions,
so a persisted child came back from resume counted as top-level and
maxDepth stopped binding after every restart. Add
SessionHeader.delegationDepth, round-trip it through the JSONL and
SQLite backends (SQLite schema v5), restore it on agent-loop resume,
and write it when the in-process backends create a child. The seam now
owns the shared depth vocabulary (delegationDepthOf): the persisted
header is authoritative and monotone — runtime options may deepen it
but never lower it.
Dudu-0223