Tianyi Cui
13c6e847a2
The hooks subsystem runs external hook commands the Claude Code / Codex way: JSON payload on stdin, context in CLAUDE_PROJECT_DIR / CLAUDE_PLUGIN_ROOT env. Reusing the ctx.bash seam for that needs two new inputs — but stdin and arbitrary env are exactly what dsh-bash-local's credential scrub exists to keep away from model-driven commands. So this adds them as a TRUSTED-PLUGIN surface: - BashExecRequest + BashExecSpec gain optional `stdin` and `env`. They are plain optionals on the resolved spec (not required-but-nullable like `owner`): a missing one means "none", the safe default, not a security footgun. - dsh-bash-local threads them through resolve/run/start. `env` merges AFTER the credential scrub, so a trusted caller's explicit entry wins even on a credential-shaped name — the scrub guards the harness's OWN ambient creds from model-driven commands, not a trusted plugin. stdin is always a pipe, closed immediately (with bytes when supplied, empty otherwise — EOF as before); an EPIPE from a child that exits without reading is swallowed. - The model-facing dsh-tool-bash NEVER forwards model input into stdin/env (its request is command/workdir/timeoutMs/signal/owner only). A regression guard drives the real tool with adversarial args and asserts the request carries neither field — proven to go red if the consumer ever forwards them. Configurable scrub (in an earlier sketch) is dropped as speculative: the explicit `env` field already gives a trusted caller full control, and no caller needs to broaden the ambient scrub. Documented in a new architecture RFC, the bash.md type-equiv blocks, and the three bash READMEs.
@deepseek-ai/dsh-bash
The bash executor seam: an abstract BashExecutor service (ctx.bash) defining WHAT a bash backend does — run commands, manage background tasks — without saying HOW.
This package is one third of the bash capability, split so each concern can evolve (and be swapped) independently:
| Package | Role |
|---|---|
@deepseek-ai/dsh-bash (this) |
the interface: abstract service + vocabulary types |
@deepseek-ai/dsh-bash-local |
an implementation: local subprocesses |
@deepseek-ai/dsh-tool-bash |
the model-facing tool schemas over ctx.bash |
The split mirrors the LLM seam (LlmService/LlmAdapter) and the agent-tool survey: pi hides execution behind a BashOperations interface (local shell / SSH / VM backends), Codex behind an exec-server protocol. A future sandboxed, containerized, or remote executor implements this interface and the tool schemas don't change.
Service API (ctx.bash)
| Member | Semantics |
|---|---|
run(spec) |
Foreground execution. Resolves when the command finishes. Rejects only for infrastructure failures (unusable workdir, missing shell, pre-aborted signal); nonzero exits, timeout kills, and abort kills resolve with a descriptive BashRunResult. |
start(spec) |
Background execution. Returns a BashTask handle immediately; no timeout applies (stop tasks via kill). |
get(id) / list() |
Task lookup. |
ownerOf(id) |
The opaque OWNER token recorded for a background task at start (from the spec's owner), or undefined for an unknown id OR a known-but-ownerless task. The executor stores/returns it verbatim and NEVER interprets it — the access POLICY lives in the consumer (dsh-tool-bash), which compares ownerOf(id) to the caller's token. Storing ownership here (disposed with the executor's fiber) is what makes it survive a consumer HMR reload. |
readOutput(id) |
Incremental output read — consecutive reads never re-deliver. Reads that lost data to buffer bounds flag lossy and point at full-stream spill files. Throws for unknown ids. |
kill(id) |
Kill a running task. Returns false when it already finished; throws for unknown ids. |
onTaskDone(listener) |
Completion listener (effect-based, disposer returned). Fires exactly once per task; never after the service is disposed. |
Implementations subclass BashExecutor, implement the abstract methods, and call notifyTaskDone(task) on background completion. Disposal must kill every running task (no orphan processes) — see the HMR-safety tests.
Vocabulary
BashExecRequest (command, workdir?, timeoutMs?, signal?, stdin?, env?, owner?) resolves to BashExecSpec (command, workdir, timeoutMs, signal?, stdin?, env?, owner) before execution; owner is optional on the request and required-but-nullable (OwnerToken | undefined) on the resolved spec, so a forgotten owner is a visible undefined rather than a silently-absent property. The task id (BashTaskId) and the owner token (OwnerToken) are branded — OwnerToken is a DISTINCT brand from SessionId (the seam never imports dsh-session; the dsh-tool-bash consumer is the single boundary that casts its SessionId into one). run() returns BashRunResult (exitCode, signal, timedOut, aborted, timeoutMs, stdout/stderr as CollectedOutput) and start()/readOutput() use BashTask/BashTaskRead for the background side. See src/types.ts for the full contracts.
stdin and env are a trusted-plugin surface: an in-process plugin (the hooks bridges, native plugins) sets them to feed a hook command its JSON payload on stdin and its CLAUDE_PROJECT_DIR/CLAUDE_PLUGIN_ROOT env. The model-facing dsh-tool-bash tool deliberately never forwards model input into either — so a model cannot smuggle an env var or stdin payload past the implementation's credential scrub. They are plain optionals on the resolved spec (unlike owner's required-but-nullable): a missing one means "none", the safe default, not a security footgun. See the trusted-plugin RFC.