Module process 

Streaming subprocess control: spawn a child, pipe its stdout/stderr line-by-line through a callback as Events, and hand back a ProcessHandle for cancellation (SIGTERM → SIGKILL).

The environment is the caller’s: this spawns what it is told to spawn, with the PATH it is given. Finding a CLI a user installed — resolving a bare name, locating the node it was installed under — is a different question, and one only a caller driving such a CLI needs answered.

Cancellation is the wrinkle: a run needs to be stoppable mid-stream when the user closes the tab or hits “stop”. ProcessHandle::cancel() sends SIGTERM (with a SIGKILL fallback) and flips an atomic cancelled flag the reader threads use to short-circuit.

Structs

Command

What to spawn. Named fields rather than six positional arguments, so a call site says which string is the program and which is the run id, and a new knob is a field with a default instead of a break.

ProcessHandle

Handle to an in-flight streaming run. Caller stores it (e.g. in a runId-keyed map) so a later cancel() can find it.

Enums

Event

Raw events emitted to the caller’s callback during a streaming run. JSON-tagged so axum SSE and Tauri Channel render identical payloads on the wire. Harness-neutral: a process-backed adapter parses the Stdout lines into a normalized event vocabulary (e.g. agent-harness’s RunEvent).

Stderr

What happens to the child’s stderr.

Stdin

What the child’s stdin is connected to.

Functions

hidden_command

needs_terminal

Compose a PATH for the spawned process that always includes the directory containing the program — where node, npm, and friends usually live in an nvm install. The user’s existing PATH stays as a fallback after our prepended directory. A Command that never opens a console window on Windows.