> For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt.

# lib.wasm

- **Type:**

```ts
type Wasm =
  | {
      mode?: 'compile' | 'preserve';
    }
  | false;
```

- **Default:**
  - When [bundle](/config/lib/bundle.md) is `true`: `{ mode: 'compile' }`
  - When [bundle](/config/lib/bundle.md) is `false`: `{ mode: 'preserve' }`
- **Top-level config:** Supported

Configure how Rslib handles `.wasm` modules. See [Wasm](/guide/advanced/wasm.md) for details.

## wasm.mode

- **Type:** `'compile' | 'preserve'`
- **Default:**
  - When [bundle](/config/lib/bundle.md) is `true`: `'compile'`
  - When [bundle](/config/lib/bundle.md) is `false`: `'preserve'`

Selects the output mode for `.wasm` modules. See [Wasm - Output modes](/guide/advanced/wasm.md#output-modes) for details.

## Version history

| Version | Changes                                                                                 |
| ------- | --------------------------------------------------------------------------------------- |
| v1.0.1  | Added support for setting `lib.wasm` to `false` to disable handling of `.wasm` modules. |