Browser Remote

Allows you to evaluate and execute JavaScript expressions in a browser, by making a request to a local web server. Useful for automation.

Installation

Install the browser_remote artifact anywhere on your machine, e.g. in /path/to/browser_remote.

Follow the instructions here to create a native messaging host manifest file for your browser(s).

Example of this file for Chrome (replace path and allowed_origins):

{
  "name": "com.jacobweber.browser_remote",
  "description": "Run JavaScript from other applications",
  "path": "/path/to/browser_remote",
  "type": "stdio",
  "allowed_origins": ["chrome-extension://jgmdchjaeklnmaikghgeiodkegiiedge/"]
}

and for Firefox (replace path):

{
  "name": "com.jacobweber.browser_remote",
  "description": "Run JavaScript from other applications",
  "path": "/path/to/browser_remote",
  "type": "stdio",
  "allowed_extensions": ["[email protected]"]
}

Install the browser_remote extension in your browser:

• For Chrome, go to Window > Extensions, enable "Developer mode", click "Load unpacked", and open the add-on folder.

• For Firefox single-session use, go to about:debugging, click "This Firefox", click "Load Temporary Add-on", and open the add-on/manifest.json file.

• For Firefox long-term use, go to Tools > Add-ons and Themes", click the gear icon, click "Install Add-on From File", and select the .xpi artifact.

Once the extension is loaded, it will start a web server on port 5555, or the next free port. You can see the URL by clicking the extension's icon.

You can now send requests to the web server, and they'll be evaluated in the front browser tab, and returned.

Request format:

POST /
{
	// an expression to evaluate and return:
	"query": "location.href"
	// or a function call:
	"query": "window.open(\"https://www.apple.com\")"
	// optional:
	"tabs": "front" (default) | "all"
}

Response format:

{
	"status": "ok" | "error message"
	// one per tab
	"results": [
		"https://www.google.com"
	]
}

Development

For Firefox add-on builds, sign up at https://addons.mozilla.org/en-US/developers/, click "Manage API Keys" to define keys, and store them as Github secrets FIREFOX_API_KEY (for JWT issuer) and FIREFOX_API_SECRET (for JWT secret).

Can't upgrade to manifest v3 due to the use of unsafe-eval.