New process/ capability family: @deepseek-ai/dsh-process owns ctx.processes — abstract ProcessManager.spawn(spec) over a fully-explicit ProcessSpawnSpec — plus the shared DSH_* managed-environment and CollectedOutput vocabulary; @deepseek-ai/dsh-process-local carries the former bash-local run.ts plumbing (detached groups, tail-keep spill-backed output, credential scrub, kill escalation, kill-and-join disposal) with no config of its own. dsh-bash-local becomes a consumer: it keeps command defaulting, the fused deadline timedOut/aborted classification, the model-friendly terminal env (now merged through the ordinary env channel), and the [stderr]-marked background read merge, and spawns through ctx.processes. Background-process lifetime moves to the manager, so an executor reload no longer kills live background work; a background spawn failure is injected once into the read path instead of being buffered as fake stderr. dsh-bash re-exports the moved vocabulary so bash consumers keep one import root; dsh-bash-sandbox only redeclares the inherited inject. Every composition loading a bash executor now loads dsh-process-local (CLI, examples, python bundled runtime, create-sdk bash feature, inline test configs).
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), and the out-of-process subagent-acp backend builds on the subagent-subprocess library (the credential env scrub, the dispose ladder, isolated config dirs). Tests replace only the child boundary with package-local fixtures.
The proposal and design rationale: .agents/notes/implemented/feature/2026-06-21-subagent-capability-seam.md.