The model-facing bash tools — `bash`, `bash_output`, `bash_kill` — registered over the `ctx.bash` executor seam (`@deepseek-ai/dsh-bash`). Pure schema + text shaping; every process concern lives behind the seam, so sandboxed or remote executor implementations swap in without changing what the model sees.
`command`, `workdir`, and `timeoutMs` are resolved against the executor's config defaults via `ctx.bash.resolve()` before execution, so the executor seam (`BashExecSpec`) receives explicit `workdir`/`timeoutMs` values.
Result text: stdout, then a `[stderr]` section, then status markers — `[timed out after Nms]` whenever the executor's timer fired (reported independently of how the process ended, so a command that traps SIGTERM and exits 0 still shows it), `[killed by signal: …]` for a signal death, `[exit code: N]` for a non-zero exit (reported, **not**`isError`: the model decides how to react), and `[output truncated; full output: <path>]` when the tail was kept. Only infrastructure failures (spawn errors, aborts) surface as `isError` results.
`task_id` → output produced **since the previous `bash_output` call** plus a status line (`running` / `completed, exit code: N` / `killed`). Reads that lost data to buffer bounds say so and point at the full-output spill file.
When a background task finishes, a short notice is injected into the owning agent's session (`agent.inject()`, source `{kind: 'plugin', plugin: 'tool-bash'}`). Injection is **durable context for the next model request, not a wake-up** — an idle agent stays idle until something sends a message. That's why the tool descriptions tell the model to poll with `bash_output`.
`TODO(permissions)`: commands run with the executor's full authority. The permission/sandbox seam is the `tools/execute` waterfall (veto or ask) plus sandboxing `BashExecutor` implementations — see docs/architecture.md. `@cordisjs/plugin-capability` (a named-permission service with a session `test()`) is a candidate building block for that work.