***

title: Browser Extensions
description: Upload and manage browser extensions that can be loaded into runtimes.
-----------------------------------------------------------------------------------

Browser extensions can be loaded into runtimes to add capabilities — ad blockers, captcha solvers, or custom tools. Upload extension binaries or import from a URL, then reference them when launching runtimes.

Access via `bctrl.browserExtensions`.

## list()

List all uploaded extensions.

```ts
const extensions = await bctrl.browserExtensions.list();
```

**Returns** `ExtensionMetadata[]`

***

## upload(request)

Upload an extension binary (.crx or .zip).

```ts
import { readFileSync } from "fs";

const ext = await bctrl.browserExtensions.upload({
  file: readFileSync("./captcha-solver.crx"),
  filename: "captcha-solver.crx",
});
console.log(ext.id);
```

| Parameter  | Type                           | Required | Description             |
| ---------- | ------------------------------ | -------- | ----------------------- |
| `file`     | `Buffer \| Uint8Array \| Blob` | Yes      | Extension binary        |
| `filename` | `string`                       | Yes      | Filename with extension |

**Returns** `ExtensionMetadata`

***

## importFromUrl(request)

Import an extension from a URL.

```ts
const ext = await bctrl.browserExtensions.importFromUrl({
  url: "https://example.com/extension.crx",
});
```

| Parameter | Type     | Required | Description                        |
| --------- | -------- | -------- | ---------------------------------- |
| `url`     | `string` | Yes      | URL to download the extension from |

**Returns** `ExtensionMetadata`

***

## get(id)

Get a specific extension by ID.

```ts
const ext = await bctrl.browserExtensions.get("ext_abc123");
```

| Parameter | Type     | Required | Description  |
| --------- | -------- | -------- | ------------ |
| `id`      | `string` | Yes      | Extension ID |

**Returns** `ExtensionMetadata`

***

## delete(id)

Delete an extension.

```ts
await bctrl.browserExtensions.delete("ext_abc123");
```

| Parameter | Type     | Required | Description  |
| --------- | -------- | -------- | ------------ |
| `id`      | `string` | Yes      | Extension ID |

***

## Usage with runtimes

Load extensions when launching an ephemeral runtime:

```ts
const runtime = await workspace.runtimes.browser("main").playwright({
  mode: "ephemeral",
  extensionIds: ["ext_abc123"],
});
```