LaTeX编译MCP服务

formatex-mcp

MCP server for the FormaTeX LaTeX compilation API. It lets an MCP client such as Claude, Claude Code, Cursor, VS Code, Codex, Windsurf, Zed or Gemini CLI compile LaTeX to PDF without a local TeX installation.

There are two ways to use it:

• Hosted endpoint, nothing to install. Point a client that speaks Streamable HTTP at https://mcp.formatex.io/mcp.
• Local binary over stdio. Install formatex-mcp (below) and let the client start it.

You need a FormaTeX API key either way. Keys start with fex_ and live at formatex.io/dashboard/api-keys.

Install the local binary

Skip this section if you only use the hosted endpoint.

Option A: go install

go install github.com/formatexio/mcp/cmd/formatex-mcp@latest

The binary formatex-mcp lands in $(go env GOPATH)/bin; make sure that directory is on your PATH.

Option B: release binary

Download the file for your platform from GitHub Releases:

Each release also carries checksums.txt with the SHA-256 of every file. Compare it with sha256sum <file> (Linux) or shasum -a 256 <file> (macOS), then make the file executable and put it on your PATH:

chmod +x formatex-mcp-darwin-arm64
mv formatex-mcp-darwin-arm64 /usr/local/bin/formatex-mcp
formatex-mcp --version

The macOS binaries are not notarized. If macOS refuses to open a file you downloaded with a browser, remove its quarantine attribute with xattr -d com.apple.quarantine /usr/local/bin/formatex-mcp.

Set up your client

Every example shows the hosted endpoint first. Replace fex_your_key_here with your key and keep files that contain it out of version control. The Claude Code, Cursor, VS Code and Codex hosted examples read the key from an environment variable or a prompt instead.

Claude Desktop and claude.ai (hosted)

1. Open Customize, then Connectors, then Add custom connector.
2. Enter the URL https://mcp.formatex.io/mcp.
3. Choose Sign in and paste your key on the FormaTeX authorize page. Or skip the sign-in and add the request header Authorization: Bearer <your key>.

claude_desktop_config.json is only for local stdio servers; remote servers are added as connectors.

Claude Desktop (local binary)

Edit ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "formatex": {
      "command": "formatex-mcp",
      "env": {
        "FORMATEX_API_KEY": "fex_your_key_here"
      }
    }
  }
}

If the app cannot find the binary, set command to its absolute path, for example /usr/local/bin/formatex-mcp, or "C:\\Users\\you\\go\\bin\\formatex-mcp.exe" on Windows (JSON needs the backslashes doubled).

Claude Code

Hosted:

claude mcp add --transport http formatex https://mcp.formatex.io/mcp \
  --header "Authorization: Bearer $FORMATEX_API_KEY"

Local binary:

claude mcp add --env FORMATEX_API_KEY=fex_your_key_here --transport stdio formatex -- formatex-mcp

To share the server with a project, put a .mcp.json at the project root (not in .claude/). An http entry needs "type": "http", and ${VAR} is expanded from your environment:

{
  "mcpServers": {
    "formatex": {
      "type": "http",
      "url": "https://mcp.formatex.io/mcp",
      "headers": {
        "Authorization": "Bearer ${FORMATEX_API_KEY}"
      }
    }
  }
}

Cursor

Add the server to .cursor/mcp.json in a project or to ~/.cursor/mcp.json for all projects. Hosted:

{
  "mcpServers": {
    "formatex": {
      "url": "https://mcp.formatex.io/mcp",
      "headers": {
        "Authorization": "Bearer ${env:FORMATEX_API_KEY}"
      }
    }
  }
}

For the local binary use "command": "formatex-mcp" and "env": { "FORMATEX_API_KEY": "fex_your_key_here" } in place of url and headers.

VS Code

Add .vscode/mcp.json. The top-level key is servers, not mcpServers. An inputs entry makes VS Code prompt for the key once and keep it out of the file:

{
  "inputs": [
    {
      "type": "promptString",
      "id": "formatex-api-key",
      "description": "FormaTeX API key",
      "password": true
    }
  ],
  "servers": {
    "formatex": {
      "type": "http",
      "url": "https://mcp.formatex.io/mcp",
      "headers": {
        "Authorization": "Bearer ${input:formatex-api-key}"
      }
    }
  }
}

For the local binary use "type": "stdio", "command": "formatex-mcp" and "env": { "FORMATEX_API_KEY": "${input:formatex-api-key}" }.

Codex

Edit ~/.codex/config.toml. Hosted, reading the key from the FORMATEX_API_KEY environment variable:

[mcp_servers.formatex]
url = "https://mcp.formatex.io/mcp"
bearer_token_env_var = "FORMATEX_API_KEY"

Local binary:

[mcp_servers.formatex]
command = "formatex-mcp"
env_vars = ["FORMATEX_API_KEY"]

Or add the local server from the command line:

codex mcp add formatex --env FORMATEX_API_KEY=fex_your_key_here -- formatex-mcp

Windsurf

Windsurf calls the remote URL serverUrl. In mcp_config.json:

{
  "mcpServers": {
    "formatex": {
      "serverUrl": "https://mcp.formatex.io/mcp",
      "headers": {
        "Authorization": "Bearer fex_your_key_here"
      }
    }
  }
}

Zed

Zed keeps MCP servers under context_servers in its settings.json:

{
  "context_servers": {
    "formatex": {
      "url": "https://mcp.formatex.io/mcp",
      "headers": {
        "Authorization": "Bearer fex_your_key_here"
      }
    }
  }
}

Gemini CLI

Gemini CLI calls the remote URL httpUrl. In ~/.gemini/settings.json:

{
  "mcpServers": {
    "formatex": {
      "httpUrl": "https://mcp.formatex.io/mcp",
      "headers": {
        "Authorization": "Bearer fex_your_key_here"
      }
    }
  }
}

Any other client

• Streamable HTTP: URL https://mcp.formatex.io/mcp with the header Authorization: Bearer <key> or X-API-Key: <key>. The endpoint does not serve SSE.
• stdio: run formatex-mcp with FORMATEX_API_KEY in its environment.

Tools

Every compile tool returns a download URL for the PDF.

Each tool carries a title and annotations, so clients can auto-approve the read-only ones. update_template replaces the saved version, so it is marked destructive and clients should ask before running it. The template tools save LaTeX source and variable definitions only; images and other assets are added in the dashboard.

Resources

Prompt

fix_latex takes latex_source, error_log and an optional engine, and returns structured instructions for diagnosing and fixing a compilation error.

Self-hosting

Run the same binary as an HTTP server:

formatex-mcp --http :9004

In HTTP mode the server holds no API key of its own: every request to /mcp carries the caller's key as Authorization: Bearer <key> or X-API-Key: <key>, and a request without one gets 401. This is how mcp.formatex.io runs.

Flags and environment

A flag overrides its environment variable.

Endpoints

With a base URL set, the server also acts as the OAuth 2.1 authorization server that remote MCP clients use to sign in:

The bearer token is the API key the user pasted, so the server issues no credential of its own. The POST endpoints are rate limited per client IP. With a base URL set, the 401 from /mcp carries a WWW-Authenticate header that points clients at the resource metadata.

Development

go vet ./...
go test ./... -race -count=1
go build -o formatex-mcp ./cmd/formatex-mcp

The server is developed in a private repository. internal/app and internal/mcp are generated from it by scripts/sync-from-api.sh /path/to/formatex-api, so edit them there and sync rather than patching them here.

License

MIT