> ## Documentation Index
> Fetch the complete documentation index at: https://bun-1dd33a4e-farm-ad2450b3-transpiler-cache-version-namespa.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Spawn a child process

Use [`Bun.spawn()`](/runtime/child-process) to spawn a child process.

```ts theme={"theme":{"light":"github-light","dark":"dracula"}}
const proc = Bun.spawn(["echo", "hello"]);

// await completion
await proc.exited;
```

***

The second argument is a configuration object.

```ts theme={"theme":{"light":"github-light","dark":"dracula"}}
const proc = Bun.spawn(["echo", "Hello, world!"], {
  cwd: "/tmp",
  env: { FOO: "bar" },
  onExit(proc, exitCode, signalCode, error) {
    // exit handler
  },
});
```

***

By default, `proc.stdout` is a `ReadableStream` of the child process's `stdout`.

```ts theme={"theme":{"light":"github-light","dark":"dracula"}}
const proc = Bun.spawn(["echo", "hello"]);

const output = await proc.stdout.text();
output; // => "hello\n"
```

***

See [Child processes](/runtime/child-process).