Review direction (tianyicui, PR #660): in a stacked PR, change all other
process-running places to use the new service.
- lsp-local: LspConnection spawns through ctx.subprocess (piped protocol
streams + a no-spill collected stderr tail); its private process-tree
helpers (POSIX group signalling, Windows taskkill, liveness polling) are
deleted in favor of the seam's handle verbs, and its buildChildEnv now
rides scrubbedParentEnv (LSP children also stop inheriting stale DSH_*).
The plugin injects 'subprocess'; compositions/tests mount
dsh-subprocess-local.
- subagent-acp: the ACP child spawns through the seam (piped ndjson streams,
inherited stderr); spawn failure surfaces through done-rejection into the
same startup race; disposal is handle.dispose with the plugin's configured
graces. dsh-subagent-subprocess is DELETED — its dispose ladder and scrub
are the seam's, and the isolated-config-dir helper had no consumer.
- mcp-client, pty-local, sdk-helper: adopt scrubbedParentEnv as the one
scrub definition (their spawns stay put by ownership: the MCP SDK and
node-pty own those calls; the SDK wizard runs outside any composition).
- Coverage: per-file 100% over every touched src file, with each v8 ignore
carrying a platform or contract reason; new suites cover stdio
dispositions, the dispose ladder tiers, injected-win32 tree semantics,
waitForExit, settled-kill/terminate no-ops, and spawn-failure disposal.
- Docs: consumer-migration Agent Note (en; zh follows in this PR), seam note
updated in place, subprocess.md rewritten for the reshaped vocabulary
(type-equiv re-registered), READMEs and SERVICE_ROLES updated, taskkill
added to knip ignoreBinaries.
The extracted library's name sat one edit away from @deepseek-ai/dsh-subagent-inprocess
(process/inprocess), inviting a typo'd import to silently resolve to the wrong
package. subagent-subprocess also reads as the deliberate counterpart to
subagent-inprocess (in-process vs. subprocess), matching how the two shared
drivers actually differ.
Package directory, npm name, module doc, JSDoc module tags, test-file name and
its temp-dir prefixes, the subagent-acp import and its Config/tsconfig/package.json
references, root tsconfig.json/tsconfig.build.json/knip.json entries, and the
packages/subagent group README all renamed together; regenerated
docs/module-graph.md and docs/config-catalog.md. Pure rename — no behavior,
export, or Config shape changed.
The credential env scrub (SENSITIVE_ENV_PATTERN/buildChildEnv), the
spawn-failure capture (spawnFailure), the child-exit waits
(waitForExit/exitsWithin), and the stdin-EOF -> SIGTERM -> SIGKILL dispose
ladder move out of subagent-acp into a new pure library package (the
subagent-inprocess shape), with the ladder taking its two grace periods as
parameters — defaults stay in the plugin Config. New isolated-config-dir
helpers (mkdtemp create, best-effort remove; a pinned dir is never removed)
land alongside for the CLAUDE_CONFIG_DIR / CODEX_HOME redirection the RFC
names.
The ACP backend migrates onto the library with no semantic change: its suite
passes with import-path edits only. bash-local keeps its sibling copy, per
the RFC's blast-radius call.
RFC: docs/rfc/proposed/feature/2026-07-07-claude-code-and-codex-subagent-backends.md
The first OUT-OF-PROCESS subagent backend, proving the seam generalizes past the
in-process backends. @deepseek-ai/dsh-subagent-acp runs each child agent in a
spawned subprocess, driven over the Agent Client Protocol as the CLIENT — the
direction-inverted twin of the dsh-acp server bridge. Point the configured
command at the acp-agent example and the harness talks to its own process.
- Fresh process per run: start spawns, runs one ACP session (initialize →
newSession → prompt), dispose kills the subprocess and awaits its exit.
- Minimal client stub: advertises no fs/terminal; accumulates agent_message_chunk
text as the result output; auto-answers session/request_permission by a
configured policy (reject default / allow). No start-time capabilities (an
out-of-process child can't enforce the parent's depth/tool-filter); ignores
request.parent; injects only `subagents`.
- StopReason mapping (end_turn→completed, cancelled→aborted, …); result resolves
error/aborted on a child failure, never rejects (seam contract).
- Security: credential-shaped ambient env vars are scrubbed; the child's own key
is forwarded only via explicit config.env. A spawn-level error (ENOENT) is
captured and raced against the ACP drive so a bad command settles error rather
than crashing the parent.
Testing designed at every tier: keyless integration drives a scripted mock ACP
server subprocess (cancellation incl. the pre-newSession race and a
torn-pipe-after-cancel, permission auto-answer, non-message updates, spawn
failure, HMR, export shape) at 100% coverage; a with-key e2e drives the REAL
acp-agent example process (PONG + real file write, verified on disk) — the
harness driving itself. Snapshot coverage of an ACP child is deferred as
TODO(acp-subagent-replay) (each child is its own process with its own replay).
Stayed on @agentclientprotocol/sdk 0.25.1: the proposed 0.28.x bump only
deprecates the stable ClientSideConnection/AgentSideConnection API this layer
uses (33 sites incl. the server bridge), turning no-deprecated red across code
this PR shouldn't rewrite — that fluent-API migration is its own follow-up. The
backend needs nothing 0.28.x adds.
This completes the subagent seam stack (PR1 interface → PR2 in-process → PR2.5
snapshot infra → PR3 ACP); the seam RFC moves to implemented/, amended.
imccyu
Tianyi Cui
imccyu
pku-xht