Partytown is a lazy-loaded library to help relocate resource intensive scripts into a [web worker](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API), and off of the [main thread](https://developer.mozilla.org/en-US/docs/Glossary/Main_thread).
The experimental `astro add` command-line tool automates the installation for you. Run one of the following commands in a new terminal window. (If you aren't sure which package manager you're using, run the first command.) Then, follow the prompts, and type "y" in the terminal (meaning "yes") for each one.
```sh
# Using NPM
npx astro add partytown
# Using Yarn
yarn astro add partytown
# Using PNPM
pnpx astro add partytown
```
Then, restart the dev server by typing `CTRL-C` and then `npm run astro dev` in the terminal window that was running Astro.
Because this command is new, it might not properly set things up. If that happens, [feel free to log an issue on our GitHub](https://github.com/withastro/astro/issues) and try the manual installation steps below.
</details>
<details>
<summary>Manual Install</summary>
First, install the `@astrojs/partytown` package using your package manager. If you're using npm or aren't sure, run this in the terminal:
Partytown should be ready to go with zero config. If you have an existing 3rd party script on your site, try adding the `type="text/partytown"` attribute:
If you open the "Network" tab from [your browser's dev tools](https://developer.chrome.com/docs/devtools/open/), you should see the `partytown` proxy intercepting this request.
This mirrors the [Partytown config object](https://partytown.builder.io/configuration), but only `debug` and `forward` are exposed by this integration.
<details>
<summary><strong>config.debug</strong></summary>
Partytown ships with a `debug` mode; enable or disable it by passing `true` or `false` to `config.debug`. If [`debug` mode](https://partytown.builder.io/debugging) is enabled, it will output detailed logs to the browser console.
If this option isn't set, `debug` mode will be on by default in [dev](https://docs.astro.build/en/reference/cli-reference/#astro-dev) or [preview](https://docs.astro.build/en/reference/cli-reference/#astro-preview) mode.
Third-party scripts typically add variables to the `window` object so that you can communicate with them throughout your site. But when a script is loaded in a web-worker, it doesn't have access to that global `window` object.
You can specify which variables to forward with the `config.forward` option. [Read more in Partytown's documentation.](https://partytown.builder.io/forwarding-events)
- The [integrations playground template](https://github.com/withastro/astro/tree/latest/examples/integrations-playground?on=github) comes with Astro Partytown installed, with a demo script that shows how Partytown moves intensive operations off of the main thread.
- [Browse projects with Astro Partytown on GitHub](https://github.com/search?q=%22@astrojs/partytown%22+filename:package.json&type=Code) for more examples!