asyncapi-tag

Render AsyncAPI documents inside Markdown pages with a single element:

<asyncapi-tag src="asyncapi.yaml"></asyncapi-tag>

asyncapi-tag is a Python-Markdown extension, so it works in any tool built on Python-Markdown. It ships with a plugin for MkDocs that resolves document paths the same way MkDocs resolves links. Rendering in the browser is done by the official AsyncAPI React component, pinned to an exact version and loaded with Subresource Integrity. JSON and YAML documents both work.

Formerly published as mkdocs-asyncapi-tag-plugin. See Migrating.

MkDocs

pip install asyncapi-tag

# mkdocs.yml
plugins:
  - asyncapi-tag

Put your AsyncAPI file anywhere under docs/ and reference it from a page. Paths are relative to the Markdown file, or relative to docs/ when they start with /. Absolute http(s):// URLs are passed through unchanged.

<!-- docs/api/events.md -->
# Events API

<asyncapi-tag src="events.yaml" sidebar="false"></asyncapi-tag>

A missing document or an invalid attribute is reported as a MkDocs warning, so mkdocs build --strict fails instead of shipping a broken page.

Plugin options

plugins:
  - asyncapi-tag:
      load_assets: true              # emit the viewer script and stylesheet (default: true)
      viewer_js: https://unpkg.com/@asyncapi/react-component@3.2.1/browser/standalone/index.js
      viewer_js_integrity: sha384-…  # set to '' to omit the integrity attribute
      viewer_css: https://unpkg.com/@asyncapi/react-component@3.2.1/styles/default.min.css
      viewer_css_integrity: sha384-…

To self-host the viewer, copy the two files into docs/ and point the options at them. Relative paths are resolved per page like src is:

plugins:
  - asyncapi-tag:
      viewer_js: assets/asyncapi/index.js
      viewer_js_integrity: ''
      viewer_css: assets/asyncapi/default.min.css
      viewer_css_integrity: ''

Or set load_assets: false and load the files yourself through extra_javascript and extra_css. The page-side runner script is still needed in that case; copy it from asyncapi_tag.assets.RUNNER_JS.

Plain Python-Markdown

import markdown

html = markdown.markdown(text, extensions=["asyncapi_tag"])

Extension options (pass them as extension_configs={"asyncapi_tag": {...}}):

Attributes

Only src is required. Attribute names are case-insensitive. Boolean attributes accept true/false, 1/0, yes/no, on/off; a bare attribute means true.

These map onto the React component's configuration. Defaults for sidebar and messageExamples follow earlier releases of this plugin rather than the viewer, so existing pages keep their look.

How it works

Each tag becomes a <div class="asyncapi-tag"> carrying the document URL and the viewer configuration as HTML-escaped data attributes. The first tag on a page also emits the viewer's stylesheet and script and a short runner script. The runner fetches each document as text, hands it to AsyncApiStandalone.render, and prints a visible error inside the container if fetching or rendering fails. No content from the Markdown source is interpolated into JavaScript.

Tags inside fenced or indented code blocks are left alone, so you can document the syntax.

Material for MkDocs users with navigation.instant enabled are covered: the runner re-scans the page on Material's document$ event.

Migrating from mkdocs-asyncapi-tag-plugin

1. Replace mkdocs-asyncapi-tag-plugin with asyncapi-tag in your requirements. The plugin id in mkdocs.yml is unchanged (asyncapi-tag).
2. Remove the asyncapi_file plugin option. MkDocs already copies every non-Markdown file under docs/ into the site; the option now only prints a deprecation warning.
3. Use a path relative to the page (or /-prefixed relative to docs/) in src. Earlier versions emitted the build machine's filesystem path, so only /-prefixed paths ever worked; those still work.
4. String attributes such as publishLabel="PUBLISH" and showServers="bySpecTags" now take effect. Earlier versions silently discarded them.

mkdocs-asyncapi-tag-plugin 1.0.0 is a deprecated shim that only depends on this package, so upgrading it also works, but no further releases will be made under the old name.

Updating the pinned viewer

python scripts/update_viewer.py          # latest @asyncapi/react-component
python scripts/update_viewer.py 3.2.1    # specific version

The script rewrites the version, URLs and SRI hashes in src/asyncapi_tag/assets.py.

Development

python -m venv .venv && source .venv/bin/activate
pip install -e ".[test]"
pytest

The JavaScript runner is syntax-checked with node when it is installed. See AGENTS.md for the repository layout and release procedure.

License

MIT