# OpenReplay Tracker The main package of the [OpenReplay](https://openreplay.com/) tracker. ## Installation ```bash npm i @openreplay/tracker ``` ## Usage Initialize the package from your codebase entry point and start the tracker. You must set the `projectKey` option in the constructor. Its value can can be found in your OpenReplay dashboard under [Preferences -> Projects](https://app.openreplay.com/client/projects). ```js import Tracker from '@openreplay/tracker'; const tracker = new Tracker({ projectKey: YOUR_PROJECT_KEY, }); tracker.start({ userID: "Mr.Smith", metadata: { version: "3.5.0", balance: "10M", role: "admin", } }); ``` Then you can use OpenReplay JavaScript API anywhere in your code. ```js tracker.setUserID('my_user_id'); tracker.setMetadata('env', 'prod'); ``` Read [our docs](https://docs.openreplay.com/) for more information.