MCP for Flarum

A Model Context Protocol server for Flarum.

It gives any MCP-compatible AI client (Claude Code, Claude Desktop, Cursor, VS Code, Windsurf, Zed, and others) full access to a Flarum forum's API: read and search discussions and posts, create threads and replies, manage users, tags and groups, moderate content, change settings, and call any third-party extension endpoint.

Flarum's whole API is uniform JSON:API, so a small set of generic tools covers the entire surface, including extensions, rather than hundreds of hand-written ones.

Tools

Generic (full API coverage):

Convenience:

Official docs (on by default):

Search and read Flarum's official 2.0 documentation so the AI can check how a setting, permission, extender, or REST endpoint is meant to work before acting. These read the public docs only (never your forum or its key), so they work in any mode, including read-only and with no API key. They read the live docs, so results always reflect the current 2.0 documentation. Turn them off with FLARUM_DOCS=0.

Extension development (on by default):

A development reference for building or reviewing a Flarum 2.0 extension: scaffolding and architecture, composer.json, the TypeScript frontend, backend (API resources/models/migrations), i18n, testing, static analysis & CI, and releasing. Combines the conventions the official docs establish, the de-facto FriendsOfFlarum standard, and patterns that prevent real production bugs. Static content, so it works in any mode, including read-only and with no API key. Turn it off with FLARUM_DEV=0.

Extension management (opt-in, off by default):

Registered only when FLARUM_EXTENSIONS=1 and the forum has the official flarum/extension-manager installed. These drive Composer on the server, so they need an admin key and write mode. See Managing extensions.

Managed hosting only (not available to self-hosters):

Two capabilities exist only on the Link Robins managed tier. They are gated on environment that only the hosting stack injects (DIAG_URL and SNAPSHOT_URL), and those point at Link Robins' own infrastructure: a self-hoster cannot set them to anything useful, so the diagnostic tools never register and the snapshot hook stays a no-op. Setting them by hand does nothing because there is no backend to answer.

Everything above this section (generic, convenience, docs, dev, and extension-management tools) is available to self-hosters. These two only activate when their hosting control-plane env vars (DIAG_URL / SNAPSHOT_URL) are set, which point at Link Robins' managed platform — so in practice they're managed-hosting-only, but nothing in the code is closed off. The MCP is MIT-licensed.

Related MCP server: discord-mcp-server

Configuration

Behind Cloudflare or a WAF

Many Flarum forums sit behind Cloudflare. Some WAF configurations block requests whose User-Agent looks scripted or empty, returning Cloudflare error 1010 (browser_signature_banned) before the request ever reaches Flarum. The server sends a descriptive, identifiable User-Agent by default for exactly this reason, so the common case works out of the box.

If your forum still blocks it, allowlist the tool rather than loosening your firewall:

• Allowlist the User-Agent. In Cloudflare, add a WAF rule like User-Agent contains "mcp-for-flarum" → Skip / Allow. The default UA is mcp-for-flarum/<version> (+https://github.com/linkrobins/mcp-for-flarum).

• Or allowlist the server IP (best for a hosted/single-source deployment).

• Or set a custom UA with FLARUM_USER_AGENT to match an existing allow rule.

Do not work around this by spoofing a browser User-Agent: it is fragile and makes the traffic impossible to allowlist or audit.

Getting an API key

Flarum has no admin UI for API keys yet. Create one directly in the database:

INSERT INTO api_keys (`key`, user_id, created_at)
VALUES (REPLACE(UUID(), '-', ''), 1, NOW());

Use the resulting key as FLARUM_API_KEY. Setting user_id (or FLARUM_USER_ID) makes the key act as that user, so its permissions are exactly that user's permissions.

Managing extensions

Set FLARUM_EXTENSIONS=1 to let the AI install, update, remove, enable, and disable extensions. This is off by default because it runs Composer on your server and can change what code your forum runs, which is far more powerful than editing content. It requires all of:

• The official flarum/extension-manager installed and enabled on the forum.

• Write mode (not FLARUM_MODE=read) and an API key whose user is an admin.

• A server that can actually run Composer: the PHP functions proc_open and escapeshellarg available, and vendor/, storage/, composer.json, and composer.lock writable.

How long-running installs are reported depends on your forum's queue:

• Background queue (Redis, database, etc. with a running worker): the call returns once the job finishes. The tools poll the manager's task list for you and return the Composer output. If no worker is consuming jobs, the call times out and says so rather than hanging.

• Synchronous (sync queue, or the manager's "run jobs in background" setting off): the request blocks until Composer finishes and returns the result inline. Very large updates can hit PHP/gateway timeouts even though Composer keeps running.

flarum_ext_install does not enable the extension unless you pass enable: true. Use flarum_ext_why_not first to confirm a package is compatible with your Flarum version. For bulk or major updates, take a backup first.

Enabling can break a forum. The manager refuses to install an extension whose published Flarum compatibility doesn't match your version, but that check is best-effort: it reads the latest stable release's declared flarum/core constraint, is skipped when Packagist is unreachable or the package declares nothing, and the version Composer actually installs can differ from the one it checked. So an extension can pass the check and still fail to boot when enabled, taking the whole site down (every page, including the admin panel and this tool's own API, starts returning a 500). The manager cannot then disable it for you: recovery means removing the extension from the extensions_enabled setting in the database and composer remove-ing it by hand. This is why install does not auto-enable by default, and why a backup before enabling unfamiliar extensions is worth it.

Install & run

Self-host it with the official Docker image, or build it from source. (It is intentionally not published to npm.)

Option 1: Docker (recommended)

For a local Claude client (stdio):

docker run -i --rm \
  -e FLARUM_URL=https://discuss.example.com \
  -e FLARUM_API_KEY=xxxxx \
  ghcr.io/linkrobins/mcp-for-flarum

Claude Code:

claude mcp add flarum -- docker run -i --rm -e FLARUM_URL=https://discuss.example.com -e FLARUM_API_KEY=xxxxx ghcr.io/linkrobins/mcp-for-flarum

Claude Desktop / Cursor / Windsurf (JSON config):

{
  "mcpServers": {
    "flarum": {
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "FLARUM_URL", "-e", "FLARUM_API_KEY", "ghcr.io/linkrobins/mcp-for-flarum"],
      "env": {
        "FLARUM_URL": "https://discuss.example.com",
        "FLARUM_API_KEY": "xxxxx"
      }
    }
  }
}

Option 2: From source (no Docker)

git clone https://github.com/linkrobins/mcp-for-flarum.git
cd mcp-for-flarum
npm install && npm run build
FLARUM_URL=https://discuss.example.com FLARUM_API_KEY=xxxxx node dist/index.js

Then point your client's command at node /absolute/path/to/mcp-for-flarum/dist/index.js.

Prefer not to run anything?

A managed, hosted version is offered by Link Robins, no install, no key management, and usable from web clients. See linkrobins.com.

Hosting (HTTP transport)

The same binary can run as a long-lived web service over Streamable HTTP, so you can host it instead of running it locally. This is what web-based clients (which can't spawn a local process) connect to.

Start in HTTP mode with --http (or MCP_TRANSPORT=http):

FLARUM_URL=https://discuss.example.com \
FLARUM_API_KEY=xxxxx \
MCP_AUTH_TOKEN=a-long-random-secret \
PORT=3000 \
node dist/index.js --http

It serves:

• POST /mcp, the MCP endpoint (Streamable HTTP, stateless)

• GET /health, health check for load balancers / uptime monitors

Hosting-specific configuration:

Security: a hosted instance can read, write, and delete on the forum its key targets. Always run it behind TLS, set MCP_AUTH_TOKEN (or front it with your own auth/OAuth proxy), and give the API key's user the least privilege it needs. The Flarum API key stays server-side and is never exposed to clients.

Docker (hosted mode)

docker run -p 3000:3000 \
  -e MCP_TRANSPORT=http \
  -e HOST=0.0.0.0 \
  -e FLARUM_URL=https://discuss.example.com \
  -e FLARUM_API_KEY=xxxxx \
  -e MCP_AUTH_TOKEN=a-long-random-secret \
  ghcr.io/linkrobins/mcp-for-flarum

HOST=0.0.0.0 is needed so the published port is reachable; the server only allows it because MCP_AUTH_TOKEN is set.

Or use the included docker-compose.yml: set your values and docker compose up -d.

Development

npm install
npm run build
FLARUM_URL=... FLARUM_API_KEY=... node dist/index.js

License

MIT © Link Robins. Free and open source — self-host it, modify it, and use it however you like.

Trademarks

Flarum is a trademark of the Flarum Foundation. This is an independent project that works with Flarum via its API; it is not affiliated with, endorsed by, or sponsored by the Flarum Foundation.