BashOutput

Fetch the current state of a background shell started via Bash with run_in_background: true.

Schema

Param	Type	Required
shell_id	string	yes

Behaviour

• Each call returns the FULL captured buffer up to the per-stream cap (1 MiB stdout, 1 MiB stderr). There’s no per-reader offset — agents should grep client-side.
• Running shells return status: running.
• Completed shells return status: completed (exit N).
• Unknown shell_id returns an error result.

Output format

command: npm run build
status: completed (exit 0)
started: 2026-04-23T14:30:22+01:00

--- stdout (1234 bytes) ---
webpack compiled successfully
...

--- stderr (0 bytes) ---

When either stream hits its cap, the header includes [TRUNCATED]:

--- stdout (1048576 bytes) [TRUNCATED] ---

Lifecycle

• Shells stay in the registry after they complete. You can BashOutput a finished shell indefinitely (until the container exits).
• To actively release registry space, call KillShell — even on an already-exited shell, this removes it from the registry.

Related

• Bash — launching background shells.
• KillShell — terminating them.