--- title: Descope 🤝 FastMCP sidebarTitle: Descope description: Secure your FastMCP server with Descope icon: shield-check --- import { VersionBadge } from "/snippets/version-badge.mdx"; This guide shows you how to secure your FastMCP server using [**Descope**](https://www.descope.com), a complete authentication and user management solution. This integration uses the [**Remote OAuth**](/servers/auth/remote-oauth) pattern, where Descope handles user login and your FastMCP server validates the tokens. ## Configuration ### Prerequisites Before you begin, you will need: 1. To [sign up](https://www.descope.com/sign-up) for a Free Forever Descope account 2. Your FastMCP server's URL (can be localhost for development, e.g., `http://localhost:3000`) ### Step 1: Configure Descope 1. Go to the [MCP Servers page](https://app.descope.com/mcp-servers) of the Descope Console, and create a new MCP Server. 2. Give the MCP server a name and description. 3. Ensure that **Dynamic Client Registration (DCR)** is enabled. Then click **Create**. 4. Once you've created the MCP Server, note your Well-Known URL. DCR is required for FastMCP clients to automatically register with your authentication server. Save your Well-Known URL from [MCP Server Settings](https://app.descope.com/mcp-servers): ``` Well-Known URL: https://.../v1/apps/agentic/P.../M.../.well-known/openid-configuration ``` ### Step 2: Environment Setup Create a `.env` file with your Descope configuration: ```bash DESCOPE_CONFIG_URL=https://.../v1/apps/agentic/P.../M.../.well-known/openid-configuration # Your Descope Well-Known URL SERVER_URL=http://localhost:3000 # Your server's base URL ``` ### Step 3: FastMCP Configuration Create your FastMCP server file and use the DescopeProvider to handle all the OAuth integration automatically: ```python server.py from fastmcp import FastMCP from fastmcp.server.auth.providers.descope import DescopeProvider # The DescopeProvider automatically discovers Descope endpoints # and configures JWT token validation auth_provider = DescopeProvider( config_url=https://.../.well-known/openid-configuration, # Your MCP Server .well-known URL base_url=SERVER_URL, # Your server's public URL ) # Create FastMCP server with auth mcp = FastMCP(name="My Descope Protected Server", auth=auth_provider) ``` ## Testing To test your server, you can use the `fastmcp` CLI to run it locally. Assuming you've saved the above code to `server.py` (after replacing the environment variables with your actual values!), you can run the following command: ```bash fastmcp run server.py --transport http --port 8000 ``` Now, you can use a FastMCP client to test that you can reach your server after authenticating: ```python from fastmcp import Client import asyncio async def main(): async with Client("http://localhost:8000/mcp", auth="oauth") as client: assert await client.ping() if __name__ == "__main__": asyncio.run(main()) ``` ## Production Configuration For production deployments, load configuration from environment variables: ```python server.py import os from fastmcp import FastMCP from fastmcp.server.auth.providers.descope import DescopeProvider # Load configuration from environment variables auth = DescopeProvider( config_url=os.environ.get("DESCOPE_CONFIG_URL"), base_url=os.environ.get("BASE_URL", "https://your-server.com") ) mcp = FastMCP(name="My Descope Protected Server", auth=auth) ```