astro/packages/astro-rss/README.md

# @astrojs/rss 📖

This package brings fast RSS feed generation to blogs and other content sites built with [Astro](https://astro.build/). For more information about RSS feeds in general, see [aboutfeeds.com](https://aboutfeeds.com/).

## Installation

Install the `@astrojs/rss` package into any Astro project using your preferred package manager:

```bash
# npm
npm i @astrojs/rss
# yarn
yarn add @astrojs/rss
# pnpm
pnpm i @astrojs/rss
```

## Example usage

The `@astrojs/rss` package provides helpers for generating RSS feeds within [Astro endpoints][astro-endpoints]. This unlocks both static builds _and_ on-demand generation when using an [SSR adapter](https://docs.astro.build/en/guides/server-side-rendering/).

For instance, say you need to generate an RSS feed for all posts under `src/content/blog/` using content collections.

Start by [adding a `site` to your project's `astro.config` for link generation](https://docs.astro.build/en/reference/configuration-reference/#site). Then, create an `rss.xml.js` file under your project's `src/pages/` directory, and [use `getCollection()`](https://docs.astro.build/en/guides/content-collections/#getcollection) to generate a feed from all documents in the `blog` collection:

```js
// src/pages/rss.xml.js
import rss from '@astrojs/rss';
import { getCollection } from 'astro:content';

export async function GET(context) {
  const posts = await getCollection('blog');
  return rss({
    title: 'Buzz’s Blog',
    description: 'A humble Astronaut’s guide to the stars',
    // Pull in your project "site" from the endpoint context
    // https://docs.astro.build/en/reference/api-reference/#contextsite
    site: context.site,
    items: posts.map((post) => ({
      // Assumes all RSS feed item properties are in post frontmatter
      ...post.data,
      // Generate a `url` from each post `slug`
      // This assumes all blog posts are rendered as `/blog/[slug]` routes
      // https://docs.astro.build/en/guides/content-collections/#generating-pages-from-content-collections
      link: `/blog/${post.slug}/`,
    })),
  });
}
```

Read **[Astro's RSS docs][astro-rss]** for more on using content collections, and instructions for globbing entries in `/src/pages/`.

## `rss()` configuration options

The `rss` default export offers a number of configuration options. Here's a quick reference:

```js
export function GET(context) {
  return rss({
    // `<title>` field in output xml
    title: 'Buzz’s Blog',
    // `<description>` field in output xml
    description: 'A humble Astronaut’s guide to the stars',
    // provide a base URL for RSS <item> links
    site: context.site,
    // list of `<item>`s in output xml
    items: [],
    // (optional) absolute path to XSL stylesheet in your project
    stylesheet: '/rss-styles.xsl',
    // (optional) inject custom xml
    customData: '<language>en-us</language>',
    // (optional) add arbitrary metadata to opening <rss> tag
    xmlns: { h: 'http://www.w3.org/TR/html4/' },
    // (optional) add trailing slashes to URLs (default: true)
    trailingSlash: false,
  });
}
```

### title

Type: `string (required)`

The `<title>` attribute of your RSS feed's output xml.

### description

Type: `string (required)`

The `<description>` attribute of your RSS feed's output xml.

### site

Type: `string (required)`

The base URL to use when generating RSS item links. We recommend using the [endpoint context object](https://docs.astro.build/en/reference/api-reference/#contextsite), which includes the `site` configured in your project's `astro.config.*`:

```ts
import rss from '@astrojs/rss';

export const GET = (context) =>
  rss({
    site: context.site,
    // ...
  });
```

### items

Type: `RSSFeedItem[] (required)`

A list of formatted RSS feed items. See [Astro's RSS items documentation](https://docs.astro.build/en/guides/rss/#generating-items) for usage examples to choose the best option for you.

When providing a formatted RSS item list, see the [`RSSFeedItem` type reference](#rssfeeditem).

### stylesheet

Type: `string (optional)`

An absolute path to an XSL stylesheet in your project. If you don’t have an RSS stylesheet in mind, we recommend the [Pretty Feed v3 default stylesheet](https://github.com/genmon/aboutfeeds/blob/main/tools/pretty-feed-v3.xsl), which you can download from GitHub and save into your project's `public/` directory.

### customData

Type: `string (optional)`

A string of valid XML to be injected between your feed's `<description>` and `<item>` tags. This is commonly used to set a language for your feed:

```js
import rss from '@astrojs/rss';

export const GET = () => rss({
    ...
    customData: '<language>en-us</language>',
  });
```

### xmlns

Type: `Record<string, string> (optional)`

An object mapping a set of `xmlns` suffixes to strings of metadata on the opening `<rss>` tag.

For example, this object:

```js
rss({
  ...
  xmlns: { h: 'http://www.w3.org/TR/html4/' },
})
```

Will inject the following XML:

```xml
<rss xmlns:h="http://www.w3.org/TR/html4/"...
```

### content

The `content` key contains the full content of the post as HTML. This allows you to make your entire post content available to RSS feed readers.

**Note:** Whenever you're using HTML content in XML, we suggest using a package like [`sanitize-html`](https://www.npmjs.com/package/sanitize-html) in order to make sure that your content is properly sanitized, escaped, and encoded.

[See our RSS documentation](https://docs.astro.build/en/guides/rss/#including-full-post-content) for examples using content collections and glob imports.

### `trailingSlash`

Type: `boolean (optional)`
Default: `true`

By default, the library will add trailing slashes to the emitted URLs. To prevent this behavior, add `trailingSlash: false` to the `rss` function.

```js
import rss from '@astrojs/rss';

export const GET = () =>
  rss({
    trailingSlash: false,
  });
```

## `RSSFeedItem`

An `RSSFeedItem` is a single item in the list of items in your feed. It represents a story, with `link`, `title`, and `pubDate` fields. There are further optional fields defined below. You can also check the definitions for the fields in the [RSS spec](https://validator.w3.org/feed/docs/rss2.html#ltpubdategtSubelementOfLtitemgt).

An example feed item might look like:

```js
const item = {
  title: 'Alpha Centauri: so close you can touch it',
  link: '/blog/alpha-centuari',
  pubDate: new Date('2023-06-04'),
  description:
    'Alpha Centauri is a triple star system, containing Proxima Centauri, the closest star to our sun at only 4.24 light-years away.',
  categories: ['stars', 'space'],
};
```

### `title`

Type: `string (required)`

The title of the item in the feed.

### `link`

Type: `string (required)`

The URL of the item on the web.

### `pubDate`

Type: `Date (required)`

Indicates when the item was published.

### `description`

Type: `string (optional)`

A synopsis of your item when you are publishing the full content of the item in the `content` field. The `description` may alternatively be the full content of the item in the feed if you are not using the `content` field (entity-coded HTML is permitted).

### `content`

Type: `string (optional)`

The full text content of the item suitable for presentation as HTML. If used, you should also provide a short article summary in the `description` field.

See the [recommendations from the RSS spec for how to use and differentiate between `description` and `content`](https://www.rssboard.org/rss-profile#namespace-elements-content-encoded).

### `categories`

Type: `string[] (optional)`

A list of any tags or categories to categorize your content. They will be output as multiple `<category>` elements.

### `author`

Type: `string (optional)`

The email address of the item author. This is useful for indicating the author of a post on multi-author blogs.

### `commentsUrl`

Type: `string (optional)`

The URL of a web page that contains comments on the item.

### `source`

Type: `object (optional)`

An object that defines the `title` and `url` of the original feed for items that have been republished from another source. Both are required properties of `source` for proper attribution.

```js
const item = {
  title: 'Alpha Centauri: so close you can touch it',
  link: '/blog/alpha-centuari',
  pubDate: new Date('2023-06-04'),
  description:
    'Alpha Centauri is a triple star system, containing Proxima Centauri, the closest star to our sun at only 4.24 light-years away.',
  source: {
    title: 'The Galactic Times',
    url: 'https://galactictimes.space/feed.xml',
  },
};
```

#### `source.title`

Type: `string (required)`

The name of the original feed in which the item was published. (Note that this is the feed's title, not the individual article title.)

#### `source.url`

Type: `string (required)`

The URL of the original feed in which the item was published.

### `enclosure`

Type: `object (optional)`

An object to specify properties for an included media source (e.g. a podcast) with three required values: `url`, `length`, and `type`.

```js
const item = {
  title: 'Alpha Centauri: so close you can touch it',
  link: '/blog/alpha-centuari',
  pubDate: new Date('2023-06-04'),
  description:
    'Alpha Centauri is a triple star system, containing Proxima Centauri, the closest star to our sun at only 4.24 light-years away.',
  enclosure: {
    url: '/media/alpha-centauri.aac',
    length: 124568,
    type: 'audio/aac',
  },
};
```

#### `enclosure.url`

Type: `string (required)`

The URL where the media can be found. If the media is hosted outside of your own domain you must provide a full URL.

#### `enclosure.length`

Type: `number (required)`

The size of the file found at the `url` in bytes.

#### `enclosure.type`

Type: `string (required)`

The [MIME type](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types) for the media item found at the `url`.

## `rssSchema`

When using content collections, you can configure your collection schema to enforce expected [`RSSFeedItem`](#items) properties. Import and apply `rssSchema` to ensure that each collection entry produces a valid RSS feed item:

```ts "schema: rssSchema,"
import { defineCollection } from 'astro:content';
import { rssSchema } from '@astrojs/rss';

const blog = defineCollection({
  schema: rssSchema,
});

export const collections = { blog };
```

If you have an existing schema, you can merge extra properties using `extends()`:

```ts ".extends({ extraProperty: z.string() }),"
import { defineCollection } from 'astro:content';
import { rssSchema } from '@astrojs/rss';

const blog = defineCollection({
  schema: rssSchema.extends({ extraProperty: z.string() }),
});
```

## `pagesGlobToRssItems()`

To create an RSS feed from documents in `src/pages/`, use the `pagesGlobToRssItems()` helper. This accepts an `import.meta.glob` result ([see Vite documentation](https://vitejs.dev/guide/features.html#glob-import)) and outputs an array of valid [`RSSFeedItem`s](#items).

This function assumes, but does not verify, you are globbing for items inside `src/pages/`, and all necessary feed properties are present in each document's frontmatter. If you encounter errors, verify each page frontmatter manually.

```ts "pagesGlobToRssItems"
// src/pages/rss.xml.js
import rss, { pagesGlobToRssItems } from '@astrojs/rss';

export async function GET(context) {
  return rss({
    title: 'Buzz’s Blog',
    description: 'A humble Astronaut’s guide to the stars',
    site: context.site,
    items: await pagesGlobToRssItems(import.meta.glob('./blog/*.{md,mdx}')),
  });
}
```

## `getRssString()`

As `rss()` returns a `Response`, you can also use `getRssString()` to get the RSS string directly and use it in your own response:

```ts "getRssString"
// src/pages/rss.xml.js
import { getRssString } from '@astrojs/rss';

export async function GET(context) {
  const rssString = await getRssString({
    title: 'Buzz’s Blog',
    ...
  });

  return new Response(rssString, {
    headers: {
      'Content-Type': 'application/xml',
    },
  });
}
```

For more on building with Astro, [visit the Astro docs][astro-rss].

[astro-rss]: https://docs.astro.build/en/guides/rss/#using-astrojsrss-recommended
[astro-endpoints]: https://docs.astro.build/en/core-concepts/astro-pages/#non-html-pages