---
layout: ~/layouts/MainLayout.astro
title: Configuration Reference
---

To configure Astro, add an `astro.config.mjs` file in the root of your project. All settings are optional.

You can view the full configuration API (including information about default configuration) on GitHub: https://github.com/snowpackjs/astro/blob/latest/packages/astro/src/@types/config.ts

```js
// Example: astro.config.mjs

/** @type {import('astro').AstroUserConfig} */
export default {
  buildOptions: {
    site: 'https://example.com',
  },
};
```

## Snowpack Config

Astro is powered internally by Snowpack. You can configure Snowpack directly by creating a `snowpack.config.mjs` file. See [snowpack.dev](https://www.snowpack.dev/reference/configuration) for full documentation on this file.