bun-types/docs/guides/process/spawn.mdx

Type definitions and documentation for Bun, an incredibly fast JavaScript runtime

---
title: Spawn a child process
sidebarTitle: Spawn child process
mode: center
---

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

```ts
const proc = Bun.spawn(["echo", "hello"]);

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

---

The second argument accepts a configuration object.

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

---

By default, the `stdout` of the child process can be consumed as a `ReadableStream` using `proc.stdout`.

```ts
const proc = Bun.spawn(["echo", "hello"]);

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

---

See [Docs > API > Child processes](/docs/runtime/child-process) for complete documentation.