Files
deepseek-harness/packages/subagent/tool-subagent
Tianyi Cui 547aacee2f fix: honor the teardown order on owner unload; make the structured commit unconditional
Adversarial-review findings (own reviewer agent), each verified and pinned:

B1: agents.register() returned a wrapper lambda, so the factory composite's
yield could not identity-nest it — on OWNER unload the unregistration (and
agent/disposed) disposed as a concurrent sibling, firing mid-drain while
the final turn was still closing (pre-existing on master; this branch's
docs re-assert the order, so it must be true). register() now returns the
EXACT cordis effect disposer (the Scope.rawDispose move); the composite
nests it and owner unload runs stop/drain -> unregister -> detach -> scope
like every other path. Regression test pins turn-end before disposed
before detach on owner unload.

B2: the structured two-phase commit could promote a stale stage when a
later capture call REUSED the orphaned stage's call id with a body that
never staged (denied downstream, or invalid args throwing pre-stage). The
runtime's pre-execute listener now clears any stale stage unconditionally
when a new capture call enters the pipeline — only a call's own body can
stage for its commit; the call-id mismatch guard becomes a defensive
second layer. Repro test: blocked capture then same-id invalid call.

C1: an explicit empty toolFilter config now fails at plugin LOAD (the
check is self-contained) instead of killing every delegation at child
setup. C2: Scope.dispose/ScopeHost.dispose @returns state the single-shot
repeat-call semantics honestly.
2026-07-09 04:48:52 +08:00
..

@deepseek-ai/dsh-tool-subagent

The model-facing subagent tool: delegate a self-contained task to a child agent and return its final output. Pure schema + lifecycle shaping over the ctx.subagents provider registry — an in-process, ACP, or future A2A backend swaps in without changing what the model sees.

Provider selection is config, not model-facing

This plugin binds to exactly one provider (Config.provider). The model sees only { description, prompt } — there is no provider/type parameter in the schema. To expose more than one transport, load the plugin more than once, each bound to a different provider and a distinct toolName (the tool registry rejects a duplicate name, so a second load that kept the default subagent name would throw). Keeping selection in config (not the schema) is the deliberate split: the service holds a multi-provider registry; the tool picks one.

The description states the provider's context contract

The tool description and the prompt parameter description are DERIVED from the bound provider's inheritsParentContext (providerWording): a fresh-context provider (spawn, ACP) gets the standalone-prompt wording ("it does not see this conversation"), an inheriting provider (fork) tells the model the child already sees the conversation's completed turns and its prompt should state only what is new. Because the description is fixed at tool registration, the tool mirrors the provider's lifecycle (subagent/provider-added/-removed): it registers when the bound provider is (or becomes) available and unregisters when the provider goes away — no load-order requirement (the cordis Loader starts sibling entries concurrently, so "listed first" never guaranteed "registered first"), and an HMR reload of the backend re-derives the wording from the fresh provider. While the provider is absent the tool simply does not exist (a ctx.logger note records the wait; a typo'd provider name shows up as a tool that never materializes).

Config key Meaning
provider (required) The ctx.subagents provider name to start runs on (spawn, fork, acp, …).
toolName The model-facing tool name to register (default subagent). Set a distinct value per load when exposing multiple providers, e.g. subagent + subagent_acp.
agentOptions Default per-child { model? } applied to every spawned child. (No per-child persona: the deployment persona is a context-wide section every agent shares.)

Lifecycle (synchronous collect)

execute starts a run on the configured provider and awaits run.result inside a try/finally that always dispose()s the run — the owned child agent/session is torn down on every path (success, error, abort), never leaked. The tool's abort signal (exec.signal) is bridged to run.cancel(). A non-completed stop reason (aborted/error/max-tokens/refusal) maps to an isError tool result rather than returning partial output as success.

Background / poll collection is deferred (see the RFC); this cut blocks the parent turn until the child finishes.