Processes

Process management inside the VM: exec, spawn, stdin, lifecycle, shell sessions, process events, and visibility.

Run commands and long-lived processes inside a VM, stream their output, and drive interactive shells. Reach for this whenever an agent needs to invoke tools, start a dev server, pipe data over stdin, or attach a terminal.

How it works

A server.ts registers a VM with its software, and each script connects with createClient and grabs a VM via client.vm.getOrCreate("my-agent"). From there the VM handle exposes the full process surface:

• exec — run a command to completion and collect stdout, stderr, and exitCode in one call.
• spawn + lifecycle — start a process for a pid, then listProcesses, getProcess, waitProcess, stopProcess (SIGTERM), and killProcess (SIGKILL).
• stdin — writeProcessStdin and closeProcessStdin to feed a running process, including an interactive sh (see shell.ts).
• subscriptions — call agent.connect() and use onProcessOutput, onProcessExit, onShellData, onShellStderr, and onShellExit. The connection filters RivetKit broadcasts to the requested process or shell.

visibility.ts shows how to enumerate and inspect everything running in the VM.

Run it

npm install
npx tsx server.ts &   # start the VM registry on :6420
npx tsx exec.ts       # then run any of the scripts (spawn.ts, stdin.ts, shell.ts, ...)

Each script prints its process output and exit codes to the console.

Source

View source on GitHub