docusaurus-plugin-mcp-server · diff
git:20261003.438a061 to git:20261006.002433b
11 added, 8 removed. Audit A to A.
---
name: "docusaurus-plugin-mcp-server"
description: "Expose a Docusaurus site's docs as an MCP server for AI agents — add the build-time plugin, deploy the MCP endpoint to any web-standard serverless/edge runtime, run it locally, serve Agent Skills over MCP, or add the install button. Load when working with docusaurus-plugin-mcp-server or its /adapters or /theme entry points."
---
# docusaurus-plugin-mcp-server
A Docusaurus plugin that, at `docusaurus build`, writes an artifact bundle (`build/mcp/bundle.json`: documents, search index, skills, manifest; 2.x also writes each as its own file), plus runtime handlers that serve them as an MCP endpoint (`docs_search` + `docs_fetch` tools, and Agent Skills via the `io.modelcontextprotocol/skills` extension) to AI agents. The endpoint speaks MCP 2026-07-28 and still serves 2025-era (`initialize`) clients.
## When to use
Load this skill when the task involves:
- Adding/configuring the plugin in `docusaurus.config.js`.
- Standing up the MCP HTTP endpoint — deploying to a serverless/edge runtime (Cloudflare Workers, modern Netlify functions, Vercel Edge, Deno, Bun) or running it locally on Node.
- Adding the `McpInstallButton` to a docs site.
- Writing a custom indexer or search provider.
- Shipping Agent Skills with the docs (the `skills` plugin option, `skills.json`).
Trigger imports: `docusaurus-plugin-mcp-server`, `docusaurus-plugin-mcp-server/adapters`, `docusaurus-plugin-mcp-server/adapters/node`, `docusaurus-plugin-mcp-server/theme`.
## Install & import
```bash
npm install docusaurus-plugin-mcp-server
```
ESM-only. Four entry points:
- `docusaurus-plugin-mcp-server` — the plugin (default export) + `McpDocsServer`, provider types, `DEFAULT_PLUGIN_OPTIONS`.
- `docusaurus-plugin-mcp-server/adapters` — the web-standard deploy handler `createWebRequestHandler`.
- `docusaurus-plugin-mcp-server/adapters/node` — `createNodeServer`/`createNodeHandler` for local dev (Node `http`), and `readArtifactBundle(dir)`.
- `docusaurus-plugin-mcp-server/theme` — `McpInstallButton`.
Peers: `zod` (>= 4.2) is required. `@docusaurus/core` (and `react`/`react-dom` for the theme button) are optional peer deps; provide them from your Docusaurus app.
## Authoritative API
The authoritative API is the published TypeScript types. Read the `.d.ts` files referenced by `exports` in `package.json` before writing calls — do not guess signatures. `dist/` is a build artifact (git-ignored), so in a fresh clone run `npm run build` first, or read the corresponding `src/*.ts`:
- `.` → `dist/index.d.ts` (plugin options, `McpDocsServer`, provider/`ProcessedDoc` types)
- `./adapters` → `dist/adapters-entry.d.ts` (`WebRequestHandlerConfig`, `ArtifactBundle`)
- `./adapters/node` → `dist/adapters-node.d.ts` (`createNodeServer`/`createNodeHandler`, `NodeAdapterOptions`, `McpServerBundleDirConfig`, `readArtifactBundle`)
- `./theme` → `dist/theme/index.d.ts` (`McpInstallButton` props)
Config shape in particular (`artifacts`/`artifactsDir`, overrides such as `instructions`/`tools`) lives in those types — read them rather than copying field lists. `McpServerFileConfig` (`docsPath`/`indexPath`) and `McpServerDataConfig` (`docs`/`searchIndexData`) are deprecated since 2.2, as are the 2.1 unions `McpServerConfig`, `WebRequestAdapterConfig`, and `NodeServerOptions` (use `McpDocsServerConfig`, `WebRequestHandlerConfig`, `NodeAdapterOptions`); don't write new code against them.
## Usage patterns
**1. Build step.** Add the plugin to the `plugins` array in `docusaurus.config.js` with a `server.name`. `docusaurus build` then writes `build/mcp/`.
**2. Deploy to a serverless/edge runtime.** Edge/Worker runtimes can't read the filesystem, so import `bundle.json` as a module and pass it as `artifacts` to `createWebRequestHandler`, which returns a standard `(request: Request) => Promise<Response>`. The handler is identical across runtimes — only the export wrapper and platform config differ:
```js
import { createWebRequestHandler } from 'docusaurus-plugin-mcp-server/adapters';
- import bundle from './build/mcp/bundle.json';
+ import bundle from './build/mcp/bundle.json' with { type: 'json' };
const handler = createWebRequestHandler({ artifacts: bundle });
```
- `name`, `version`, and `baseUrl` default to what the site was built with; pass them only to override. Skills are in the bundle, so there's nothing to wire up.
+ Keep `with { type: 'json' }`: Node.js (Vercel's runtime) and Deno require it, and esbuild, Wrangler, and Bun accept it. `name`, `version`, and `baseUrl` default to what the site was built with; pass them only to override. Skills are in the bundle, so there's nothing to wire up. Serve the endpoint at `/mcp` (what the install button advertises) or set the plugin's `server.url`.
- Per-platform glue to scaffold:
+ Per-platform glue to scaffold (complete, tested setups: https://docusaurus-plugin-mcp-server.vercel.app/docs/deploy):
- - **Cloudflare Workers** — `export default { fetch: handler }`; add a `wrangler.toml` whose `main` is the worker entry. Wrangler imports `.json` files as parsed JSON on its own; add no `[[rules]]` for them.
- - **Deno / Bun** — `export default { fetch: handler }` (both honor the `fetch` default export).
- - **Modern Netlify functions** — `export default async (request) => handler(request)` (the new web-standard functions API, not the legacy `event`/`context` one).
- - **Vercel** — use the Edge runtime: `export const config = { runtime: 'edge' }` and `export default handler`.
+ - **Vercel** — `api/mcp.mjs` with `export default { fetch: handler }` (Node.js runtime; no Edge config needed), plus `vercel.json` with `"cleanUrls": true` (pages 404 without it when `trailingSlash: false`) and `"rewrites": [{ "source": "/mcp", "destination": "/api/mcp" }]`. Import path `../build/mcp/bundle.json`.
+ - **Netlify** — `netlify/functions/mcp.mjs` with `export default (request) => handler(request)` and `export const config = { path: '/mcp' }`; `netlify.toml` with `publish = "build"` and `[functions] node_bundler = "esbuild"`. Import path `../../build/mcp/bundle.json`.
+ - **Cloudflare Workers** — `worker.js` routing `/mcp` to `handler` and everything else to `env.ASSETS.fetch(request)`; `wrangler.jsonc` with `assets: { directory: './build', binding: 'ASSETS', run_worker_first: ['/mcp'] }`. No `nodejs_compat` needed. Wrangler imports `.json` files as parsed JSON on its own; add no `[[rules]]` for them.
+ - **Deno / Bun** — `Deno.serve(...)` / `Bun.serve({ routes: { '/mcp': handler }, ... })`, serving `build/` for other paths.
+ - **GitHub Pages / static hosts** — can't run the handler; deploy it elsewhere from the same build and set the plugin's `server.url` to it.
+ Use `.mjs` for function files unless the site's `package.json` has `"type": "module"` (most Docusaurus sites don't).
+
**3. Run locally.** From `docusaurus-plugin-mcp-server/adapters/node`, `createNodeServer({ artifactsDir: './build/mcp' })` returns an `http.Server` you `.listen()`. Use `createNodeHandler(...)` to mount into an existing `http.createServer` or Express app (`app.all('/mcp', ...)`; it uses `req.body` if `express.json()` ran first). `McpDocsServer.handleHttpRequest` is deprecated in its favor. For `new McpDocsServer(...)` in Node, pass `artifacts: await readArtifactBundle('./build/mcp')`.
**Custom indexers and search providers.** The plugin always writes the documents. An indexer's `finalize()` may return `search-index.json` (becomes the bundle's search index; only one indexer may) and other relative ASCII filenames (indexer extras); `bundle.json`/`manifest.json`/`skills.json`, or anything that would overwrite them, fails the build. A runtime search provider is the server config's `search` option. Since 2.2 it only needs to be a `SearchRanker`: `{ name, search(query, options) }`, a plain object or a class, passed as an instance or as a module path (`search: './my-search.js'`) that default-exports one; `initialize`, `getDocument`, and `getDocCount` are optional (without the last two, `docs_fetch` and the status count use the bundle). Only `loadSearchProvider()` called directly with a module path still requires a full `SearchProvider`. With an `artifacts`/`artifactsDir` server config, `initialize` gets it all as `initData.bundle` (`docs`, `searchIndex`, `extras`); with the deprecated configs it gets the 2.1 `initData`. Don't write `isReady()` or `healthCheck()` in new providers: both are deprecated since 2.2 (reject from `initialize()` or throw from `search()` instead; the server never called `healthCheck()`), and 3.0 drops them. Existing `SearchProvider` implementations and callers still compile.
**Skills.** By default the build packages a built-in `docs-research` skill (search → fetch → cite), loaded from the package's `skills-builtin/docs-research/SKILL.md`. Its description is built from the site `title`, URL and `tagline`, and it gets a generated "Where things are" section grouping the indexed pages by URL path. For a skill that knows the product, write your own `docs-research` in the skills dir (same name replaces the built-in); if you start from a copy of the built-in, replace its `{{siteDocs}}`/`{{siteSummary}}`/`{{siteMap}}` placeholders, which only the built-in gets filled. Add site skills with the plugin option `skills: { dir: 'mcp-skills' }` (site-relative; one directory per skill, each with a `SKILL.md` whose frontmatter `name` matches the directory). `skills: { builtin: false, dir }` ships only yours; `skills: false` disables skills. The server serves them as `skill://<name>/<path>` resources, implements `skills/list`/`skills/get`, and lists the URIs in `instructions` for clients without the extension.
- **4. Install button.** Render `McpInstallButton` (from `./theme`) in a navbar component with your `serverUrl`/`serverName`.
+ **4. Install button.** Render `McpInstallButton` (from `./theme`); with no props it reads the URL and name from the plugin. For the navbar, register it as a custom item type by swizzle-wrapping `src/theme/NavbarItem/ComponentTypes.js` (`{ ...ComponentTypes, 'custom-mcpInstall': MyItem }`) and add `{ type: 'custom-mcpInstall', position: 'right' }` to `themeConfig.navbar.items`.
## Common mistakes
- **Filesystem paths on edge/Workers.** `artifactsDir` (and the deprecated `docsPath`/`indexPath`) only work where there's a filesystem (local Node). On Workers/edge, import `bundle.json` and pass it as `artifacts`.
- **Passing the wrong file as `artifacts`.** It must be `bundle.json`, not `docs.json`; the server rejects anything without a `formatVersion` and says what it expected.
- **Don't add a Wrangler `Data` rule for JSON.** A `[[rules]] type = "Data"` rule for `**/*.json` turns the `bundle.json` import into raw bytes, so the server rejects it ("missing formatVersion"). Wrangler already imports JSON as parsed objects.
- **Reaching for removed handlers.** `createVercelHandler`, `createNetlifyHandler`, `createCloudflareHandler`, and `generateAdapterFiles` were all removed — there is one generic deploy handler, `createWebRequestHandler`. The Node server lives at `docusaurus-plugin-mcp-server/adapters/node`, not `/adapters`.
- **Wrong page URLs.** Page URLs in `docs_search` and `docs_fetch` come from the build: set `url` (and `baseUrl`) in `docusaurus.config.*` and rebuild. The server's `baseUrl` option doesn't change them; it only changes what the status reports and what search providers receive.
- **Deploying before building.** The handler needs `build/mcp/*` — run `docusaurus build` first.
- **Forgetting to pass skills (deprecated configs only).** With `artifacts`/`artifactsDir`, skills come from the bundle. With the deprecated configs, the handler only serves skills when you pass `skills` or `skillsPath`.
- **Invalid skill directories fail the build.** Frontmatter must have `name` (lowercase, hyphens, matching the directory) and `description`; each skill is capped at 512 files / 16 MiB.
- **zod 3.** 2.x requires zod >= 4.2 (MCP SDK v2).
- **1.x search options.** The built-in search is `'local'` (BM25). `'flexsearch'` in `indexers`/`search`, and the `flexsearch` plugin/server option, now throw. A 1.x `search-index.json` is rejected until the site is rebuilt; the error is returned in MCP responses and the GET status. Tune ranking with the server option `localSearch: { fieldBoosts }`. The plugin's `search` option does not choose the runtime provider (it has done nothing since 2.0, is deprecated since 2.2, and is removed in 3.0); the server config's `search` does.
- **Very long queries.** `docs_search` accepts up to 500 characters and searches the first 16 distinct terms.
- **Guessing whether search is good enough.** Measure it: `evaluateSearch(provider, [{ query, expected: [routes] }])` reports top-k hits and MRR for any provider.
## Version notes
**On 2.2+ with the deprecated server configs?** Follow `node_modules/docusaurus-plugin-mcp-server/migrations/2.x-3.0.0.md`; its "For agents" checklist moves a project to `artifacts`/`artifactsDir` so 3.0 needs nothing more.
**Migrating a project from 1.x to 2.0?** Follow `node_modules/docusaurus-plugin-mcp-server/migrations/1.x-2.0.0.md` (published with the package, and on GitHub at `scalvert/docusaurus-plugin-mcp-server`). Its "For agents" section is a step-by-step checklist; errors thrown for 1.x configuration link to it.
Check the installed version with `npm ls docusaurus-plugin-mcp-server`. 2.0 requires Node.js >= 22, moved to the MCP TypeScript SDK v2 (`@modelcontextprotocol/server`) and protocol 2026-07-28 (2025-era clients still served), added skills, made `docsSearchTool.inputSchema`/`docsFetchTool.inputSchema` `z.object(...)` schemas (raw shapes remain as `docsSearchInputSchema`/`docsFetchInputSchema`), returns JSON-RPC `-32602` for unknown tools, and replaced the FlexSearch index with BM25 local search (`'local'`, `localSearch.fieldBoosts`, `evaluateSearch`, and exported `LocalSearchIndexer`/`LocalSearchProvider`). The adapter surface consolidated to one web-standard `createWebRequestHandler`; `createVercelHandler`/`createNetlifyHandler`/`generateAdapterFiles` are gone, and `createCloudflareHandler` was removed in 1.0.0 (it was a deprecated alias through 0.13.0). The Node server/handler moved to the `./adapters/node` subpath. Confirm exports against `dist/adapters-entry.d.ts` and `dist/adapters-node.d.ts` for the version you have.