Each `*.ts` file in an outputs folder is one unit. The pipeline finds them by listing the folder in file-name order; adding one needs no edit to a shared index. A file exports exactly one `Output`, under any export name, and its `name` must equal the file name without `.ts`. A file that exports no output is a helper and is not run.

| Name | Writes |
| --- | --- |
| `agents-md` | `AGENTS.md`, a guide to the built site for agents. |
| `changelog-feed` | `changelog.xml`, an Atom feed of the changelog page's dated release headings. |
| `code-meta-check` | No files: reports fence meta that names lines the fence does not have. |
| `context-pack` | `pack/<topic>.md` for each topic in `_data/context-packs.yml`: the best pages for the topic, trimmed to its token budget, with each page's URL and source path. |
| `drift-report` | `drift.json`, every drift finding grouped by page URL. |
| `examples-report` | `examples.json`, per page: the runnable examples and how many passed, failed, or were skipped. |
| `feed` | `changes.xml`, an Atom feed of the 30 most recently changed doc pages, when the config has `url`. |
| `footnote-check` | No files: reports footnote references with no definition. |
| `html` | One HTML file per document page, at the page's pretty URL. |
| `link-check` | No files: reports internal links and heading anchors that do not resolve. |
| `llms` | `llms.txt`, following llmstxt.org. |
| `llms-full` | `llms-full.txt`, every page's Markdown in one file. |
| `manifest` | `.mizzen/manifest.json`, the page list, per-page source and HTML hashes, and the build hash. |
| `not-found` | `404.html`, the page at `/404/` when the site has one, else a minimal page. |
| `opensearch` | `opensearch.xml`, the site's search as an OpenSearch provider, when the config has `url`. |
| `page-agent` | One JSON file per document page with an `agent:` block (`agent.json` for a pretty URL): URL, source, and the page's instructions. |
| `page-json` | One JSON file per document page (`index.json` for a pretty URL): URL, title, description, headings, source, last change, and estimated tokens. |
| `pages-files` | `.nojekyll`, and `CNAME` when the config's `url` is a custom domain on GitHub Pages. |
| `reading-time` | `reading-time.json`, the word count and reading minutes of each doc page. |
| `redirects` | One HTML redirect page per old path, and `_redirects` for hosts that read it. |
| `related` | `related.json`, the few pages each doc page is most related to. |
| `review-coverage` | `review-coverage.json`, each doc page's review policy, reviewers, last review, and coverage state. |
| `robots` | `robots.txt`, with the sitemap address when the config has `url`. |
| `search` | `pagefind/`, a static search index. |
| `search-synonyms` | `pagefind.yml`, the search synonyms from `_data/search-synonyms.yml`. |
| `site-files` | No files: names the root files a site may own (`llms.txt`, `llms-full.txt`, `robots.txt`, `sitemap.xml`) so its own copy wins. |
| `sitemap` | `sitemap.xml`. |
| `sourcemap` | `sourcemap.json`, the line-exact source map (format). |
| `translations` | `translations.json`, each page's status in every configured language. |
| `trust` | `trust.json`, each doc page's trust level, reasons, and last reviewer. |
| `twins` | One Markdown twin per document page: the same URL with `.md` in place of the HTML file. |
| `variables` | `variables.json`, every variable placeholder a page uses and its declaration. |
| `version-diff` | `diff/<version>/<path>.json` for each adjacent pair of versions whose page sections differ. |
| `versions` | `versions.json`, the versions each page path exists in and how it differs from the newest. |

`outputs` in `mizzen.yml` turns one off by name:

```yaml
outputs:
  twins: false
  search: false
```

The contract is in `src/contracts/output.ts`:

```ts
interface Output {
  readonly name: string;
  run(site: Site, ctx: OutputContext): Promise<readonly OutputFile[]>;
}
```

`ctx.renderPage(page)` renders a page to a complete HTML document through the theme. `ctx.report(diagnostic)` records a finding; an output reports a content problem instead of throwing. `run()` returns files sorted by path, each `{ path, contents }`, where `path` is relative to the output folder and uses `/`, and `contents` is a string (UTF-8, LF) or a `Uint8Array`.

A custom outputs folder is passed to `build()` as `outputsDir`. It replaces the built-in folder for that build, so a custom output can either live beside the built-ins or be the whole set.

<!-- readme-example: custom-output -->
```ts
import type { Output } from "@velella/mizzen/contracts";

/** Writes feed.txt; the file name must be feeds.ts, so the output's name is feeds. */
export const feeds: Output = {
  name: "feeds",
  async run() {
    return [{ path: "feed.txt", contents: "hello\n" }];
  },
};
```