Tianyi Cui
84f3019310
Address review: `agentType` was a Claude-Code concept (`subagent_type`) that does not fit our own subagent seam — nothing in the harness interprets it, and its only consumer was the CC-dialect hook bridge. Rather than let a foreign concept sit on the core seam, remove it: - `SubagentStartRequest`, `SubagentRunInfo`, `SubagentRunEndInfo`: drop the `agentType` field; the `subagent/start`/`subagent/end` payloads now carry `provider`/`id` (+ end `stopReason`/`lastAssistantMessage`) only. - `dsh-tool-subagent`: drop `Config.agentType` and its request plumbing. - Tests: keep the lastAssistantMessage / clone-containment / reject-path coverage (rewritten to not assert agentType); delete the two tool-subagent tests that only exercised agentType forwarding (dead behavior). - Docs: retitle + rewrite the subagent-observe-enrich RFC to the one shipped enrichment (lastAssistantMessage), with a note on why agentType was dropped; update rfc/README index title, both subagent READMEs, and the core-data-structures/subagent.md type-equiv block + prose; regenerate catalog. The CC bridge (PR-F) will feed Claude Code's own default matcher value "general-purpose" for its SubagentStart/Stop agent_type matcher instead.
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 (pure lib; registers nothing) | — |
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-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 pure library — both depend on it, neither on the other), and the out-of-process subagent-acp backend 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.