Yichen Jiang
815365dbbe
# Conflicts: # docs/config-catalog.md # docs/cordis-catalog/events.md # docs/cordis-catalog/services.md # docs/core-data-structures/core.md # docs/event-producer-consumer.md # docs/persistence-catalog.md # examples/acp-agent/tests/snapshots/advanced-toolchain/session.1.jsonl # examples/acp-agent/tests/snapshots/advanced-toolchain/session.2.jsonl # examples/acp-agent/tests/snapshots/advanced-toolchain/session.jsonl # examples/acp-agent/tests/snapshots/both-mode-turn/session.jsonl # examples/acp-agent/tests/snapshots/hook-cc-pretool-ask/session.jsonl # examples/acp-agent/tests/snapshots/skill-load/session.jsonl # examples/acp-agent/tests/snapshots/text-turn/session.jsonl # examples/sandbox-acp-agent/cordis.yml # examples/sandbox-acp-agent/tests/snapshots/escalation-approved/session.jsonl # examples/sandbox-acp-agent/tests/snapshots/escalation-rejected/session.jsonl # examples/sandbox-acp-agent/tests/snapshots/mode-switching/session.jsonl # packages/compact/compact-basic/README.md # packages/compact/compact-basic/src/index.ts # packages/compact/compact-basic/tests/compact-basic.spec.ts # packages/core/agent-loop/README.md # packages/core/agent-loop/src/loop.ts # packages/core/agent-loop/tests/properties.spec.ts # packages/core/session/README.md # packages/core/session/src/types.ts # packages/core/session/tests/derived-cache.spec.ts # packages/llm/llm-deepseek/src/index.ts # packages/llm/llm-pi-ai/README.md # packages/llm/llm-pi-ai/src/adapter.ts # packages/llm/llm-pi-ai/src/convert.ts # packages/llm/llm-pi-ai/tests/adapter.spec.ts # packages/llm/llm/README.md # packages/llm/llm/src/call-config.ts # packages/llm/llm/src/index.ts # packages/ui/acp-agent/src/index.ts # packages/ui/acp/tests/harness.ts # packages/ui/jsonrpc/README.md # packages/ui/jsonrpc/src/server.ts # packages/ui/stdio-agent/README.md # packages/ui/stdio-agent/src/index.ts # python/sdk/README.i18n.yaml
subagent/ — subagent capability family
The subagent seam: an agent delegating work to a child agent. Like the bash and llm families this is a capability seam (see capability seams) — but with one defining difference: multiple provider implementations coexist in one context, registered by name, rather than the single-implementation bash shape. The registry mirrors the LLM adapter registry.
| Package | Role | ctx key |
|---|---|---|
subagent/ |
Abstract subagent seam: named-provider registry + vocabulary | ctx.subagents |
subagent-inprocess/ |
Shared in-process run driver (no provider; one cleanup effect per run) | — |
subagent-spawn/ |
In-process backend: a fresh child agent | (registers on ctx.subagents) |
subagent-fork/ |
In-process backend: a child seeded with the parent's completed-turn prefix | (registers on ctx.subagents) |
subagent-subprocess/ |
Shared out-of-process machinery: env scrub, dispose ladder, isolated config dirs (pure lib; registers nothing) | — |
subagent-acp/ |
Out-of-process backend: a child agent in a spawned subprocess, driven over ACP | (registers on ctx.subagents) |
tool-subagent/ |
Model-facing subagent delegation tool over ctx.subagents |
(registers on ctx.tools) |
The interface lives at subagent/subagent/. The in-process subagent-spawn / subagent-fork backends share the subagent-inprocess driver (a library with no provider of its own — both depend on it, neither on the other), the out-of-process subagent-acp backend builds on the subagent-subprocess library (the credential env scrub, the dispose ladder, isolated config dirs) and ships alongside them here; the test-only dsh-subagent-mock (in support) is separate. All product packages except the mock.
The proposal and design rationale: docs/rfc/implemented/feature/2026-06-21-subagent-capability-seam.md.