Outputs

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:

outputs:
  twins: false
  search: false

The contract is in src/contracts/output.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.

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" }];
  },
};