> ## Documentation Index
> Fetch the complete documentation index at: https://gofastmcp.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Descope 🤝 FastMCP

> Secure your FastMCP server with Descope

New in version `2.12.4`

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**](https://gofastmcp.com/docs/servers/auth/remote-oauth.md) 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. Create an MCP Server**

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.

> [!WARNING]
>
> DCR is required for FastMCP clients to automatically register with your authentication server.

**2. Note Your Well-Known URL**

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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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)
```


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