555 Mcp 161c6f6d

import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';
import Image from '@theme/IdealImage';

# MCP Overview

LiteLLM Proxy provides an MCP Gateway that allows you to use a fixed endpoint for all MCP tools and control MCP access by Key, Team. 

<Image 
  img={require('../img/mcp_2.png')}
  style={{width: '100%', display: 'block', margin: '2rem auto'}}
/>
<p style={{textAlign: 'left', color: '#666'}}>
  LiteLLM MCP Architecture: Use MCP tools with all LiteLLM supported models
</p>

## Overview
| Feature | Description |
|---------|-------------|
| MCP Operations | • List Tools<br/>• Call Tools <br/>• Prompts <br/>• Resources |
| Supported MCP Transports | • Streamable HTTP<br/>• SSE<br/>• Standard Input/Output (stdio) |
| LiteLLM Permission Management | • By Key<br/>• By Team<br/>• By Organization |

:::caution MCP protocol update
Starting in LiteLLM v1.80.18, the LiteLLM MCP protocol version is `2025-11-25`.<br/> 
LiteLLM namespaces multiple MCP servers by prefixing each tool name with its MCP server name, so newly created servers now must use names that comply with SEP-986—noncompliant names cannot be added anymore. Existing servers that still violate SEP-986 only emit warnings today, but future MCP-side rollouts may block those names entirely, so we recommend updating any legacy server names proactively before MCP enforcement makes them unusable.
:::

## Adding your MCP

### Prerequisites

To store MCP servers in the database, you need to enable database storage:

**Environment Variable:**
```bash
export STORE_MODEL_IN_DB=True
```

**OR in config.yaml:**
```yaml
general_settings:
  store_model_in_db: true
```

#### Fine-grained Database Storage Control

By default, when `store_model_in_db` is `true`, all object types (models, MCPs, guardrails, vector stores, etc.) are stored in the database. If you want to store only specific object types, use the `supported_db_objects` setting.

**Example: Store only MCP servers in the database**

```yaml title="config.yaml" showLineNumbers
general_settings:
  store_model_in_db: true
  supported_db_objects: ["mcp"]  # Only store MCP servers in DB

model_list:
  - model_name: gpt-4o
    litellm_params:
      model: openai/gpt-4o
      api_key: sk-xxxxxxx
```

**See all available object types:** [Config Settings - supported_db_objects](./proxy/config_settings.md#general_settings---reference)

If `supported_db_objects` is not set, all object types are loaded from the database (default behavior).

For diagnosing connectivity problems after setup, see the [MCP Troubleshooting Guide](./mcp_troubleshoot.md).

<Tabs>
<TabItem value="ui" label="LiteLLM UI">

On the LiteLLM UI, Navigate to "MCP Servers" and click "Add New MCP Server".

On this form, you should enter your MCP Server URL and the transport you want to use.

LiteLLM supports the following MCP transports:
- Streamable HTTP
- SSE (Server-Sent Events)
- Standard Input/Output (stdio)

<Image 
  img={require('../img/add_mcp.png')}
  style={{width: '80%', display: 'block', margin: '0'}}
/>

<br/>
<br/>

### Add HTTP MCP Server

This video walks through adding and using an HTTP MCP server on LiteLLM UI and using it in Cursor IDE.

<iframe width="840" height="500" src="https://www.loom.com/embed/e2aebce78e8d46beafeb4bacdde31f14" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>

<br/>
<br/>

### Add SSE MCP Server

This video walks through adding and using an SSE MCP server on LiteLLM UI and using it in Cursor IDE.

<iframe width="840" height="500" src="https://www.loom.com/embed/07e04e27f5e74475b9cf8ef8247d2c3e" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>

<br/>
<br/>

### Add STDIO MCP Server

For stdio MCP servers, select "Standard Input/Output (stdio)" as the transport type and provide the stdio configuration in JSON format:

<Image 
  img={require('../img/add_stdio_mcp.png')}
  style={{width: '80%', display: 'block', margin: '0'}}
/>

<br/>
<br/>

### OAuth Configuration & Overrides

LiteLLM attempts [OAuth 2.0 Authorization Server Discovery](https://datatracker.ietf.org/doc/html/rfc8414) by default. When you create an MCP server in the UI and set `Authentication: OAuth`, LiteLLM will locate the provider metadata, dynamically register a client, and perform PKCE-based authorization without you providing any additional details.

**Customize the OAuth flow when needed:**

<Image 
  img={require('../img/mcp_oauth.png')}
  style={{width: '80%', display: 'block', margin: '0'}}
/>

- **Provide explicit client credentials** – If the MCP provider does not offer dynamic client registration or you prefer to manage the client yourself, fill in `client_id`, `client_secret`, and the desired `scopes`.
- **Override discovery URLs** – In some environments, LiteLLM might not be able to reach the provider's metadata endpoints. Use the optional `authorization_url`, `token_url`, and `registration_url` fields to point LiteLLM directly to the correct endpoints.

<br/>

### Static Headers

Sometimes your MCP server needs specific headers on every request. Maybe it's an API key, maybe it's a custom header the server expects. Instead of configuring auth, you can just set them directly.

<Image 
  img={require('../img/static_headers.png')}
  style={{width: '80%', display: 'block', margin: '0'}}
/>

These headers get sent with every request to the server. That's it.


**When to use this:**
- Your server needs custom headers that don't fit the standard auth patterns
- You want full control over exactly what headers are sent
- You're debugging and need to quickly add headers without changing auth configuration

</TabItem>

<TabItem value="config" label="config.yaml">

Add your MCP servers directly in your `config.yaml` file:

```yaml title="config.yaml" showLineNumbers
model_list:
  - model_name: gpt-4o
    litellm_params:
      model: openai/gpt-4o
      api_key: sk-xxxxxxx

litellm_settings:
  # MCP Aliases - Map aliases to server names for easier tool access
  mcp_aliases:
    "github": "github_mcp_server"
    "zapier": "zapier_mcp_server"
    "deepwiki": "deepwiki_mcp_server"

mcp_servers:
  # HTTP Streamable Server
  deepwiki_mcp:
    url: "https://mcp.deepwiki.com/mcp"
  # SSE Server
  zapier_mcp:
    url: "https://actions.zapier.com/mcp/sk-akxxxxx/sse"
  
  # Standard Input/Output (stdio) Server - CircleCI Example
  circleci_mcp:
    transport: "stdio"
    command: "npx"
    args: ["-y", "@circleci/mcp-server-circleci"]
    env:
      CIRCLECI_TOKEN: "your-circleci-token"
      CIRCLECI_BASE_URL: "https://circleci.com"
  
  # Full configuration with all optional fields
  my_http_server:
    url: "https://my-mcp-server.com/mcp"
    transport: "http"
    description: "My custom MCP server"
    auth_type: "api_key"
    auth_value: "abc123"
```

**Configuration Options:**
- **Server Name**: Use any descriptive name for your MCP server (e.g., `zapier_mcp`, `deepwiki_mcp`, `circleci_mcp`)
- **Alias**: This name will be prefilled with the server name with "_" replacing spaces, else edit it to be the prefix in tool names
- **URL**: The endpoint URL for your MCP server (required for HTTP/SSE transports)
- **Transport**: Optional transport type (defaults to `sse`)
  - `sse` - SSE (Server-Sent Events) transport
  - `http` - Streamable HTTP transport
  - `stdio` - Standard Input/Output transport
- **Command**: The command to execute for stdio transport (required for stdio)
- **allow_all_keys**: Set to `true` to make the server available to every LiteLLM API key, even if the key/team doesn't list the server in its MCP permissions.
- **Args**: Array of arguments to pass to the command (optional for stdio)
- **Env**: Environment variables to set for the stdio process (optional for stdio)
- **Description**: Optional description for the server
- **Auth Type**: Optional authentication type. Supported values:

  | Value | Header sent |
  |-------|-------------|
  | `api_key` | `X-API-Key: <auth_value>` |
  | `bearer_token` | `Authorization: Bearer <auth_value>` |
  | `basic` | `Authorization: Basic <auth_value>` |
  | `authorization` | `Authorization: <auth_value>` |

- **Extra Headers**: Optional list of additional header names that should be forwarded from client to the MCP server
- **Static Headers**: Optional map of header key/value pairs to include every request to the MCP server.
- **Spec Version**: Optional MCP specification version (defaults to `2025-06-18`)

Examples for each auth type:

```yaml title="MCP auth examples (config.yaml)" showLineNumbers
mcp_servers:
  api_key_example:
    url: "https://my-mcp-server.com/mcp"
    auth_type: "api_key"
    auth_value: "abc123"        # headers={"X-API-Key": "abc123"}

  # NEW – OAuth 2.0 Client Credentials (v1.77.5)
  oauth2_example:
    url: "https://my-mcp-server.com/mcp"
    auth_type: "oauth2"         # 👈 KEY CHANGE
    authorization_url: "https://my-mcp-server.com/oauth/authorize" # optional override
    token_url: "https://my-mcp-server.com/oauth/token"             # optional override
    registration_url: "https://my-mcp-server.com/oauth/register"   # optional override
    client_id: os.environ/OAUTH_CLIENT_ID
    client_secret: os.environ/OAUTH_CLIENT_SECRET
    scopes: ["tool.read", "tool.write"] # optional override

  bearer_example:
    url: "https://my-mcp-server.com/mcp"
    auth_type: "bearer_token"
    auth_value: "abc123"        # headers={"Authorization": "Bearer abc123"}

  basic_example:
    url: "https://my-mcp-server.com/mcp"
    auth_type: "basic"
    auth_value: "dXNlcjpwYXNz"  # headers={"Authorization": "Basic dXNlcjpwYXNz"}

  custom_auth_example:
    url: "https://my-mcp-server.com/mcp"
    auth_type: "authorization"
    auth_value: "Token example123"  # headers={"Authorization": "Token example123"}

  # Example with extra headers forwarding
  github_mcp:
    url: "https://api.githubcopilot.com/mcp"
    auth_type: "bearer_token"
    auth_value: "ghp_example_token"
    extra_headers: ["custom_key", "x-custom-header"]  # These headers will be forwarded from client

  # Example with static headers
  my_mcp_server:
    url: "https://my-mcp-server.com/mcp"
    static_headers: # These headers will be requested to the MCP server
      X-API-Key: "abc123"
      X-Custom-Header: "some-value"
```

### MCP Walkthroughs

- **Strands (STDIO)** – [watch tutorial](https://screen.studio/share/ruv4D73F)

> Add it from the UI

```json title="strands-mcp" showLineNumbers
{
  "mcpServers": {
    "strands-agents": {
      "command": "uvx",
      "args": ["strands-agents-mcp-server"],
      "env": {
        "FASTMCP_LOG_LEVEL": "INFO"
      },
      "disabled": false,
      "autoApprove": ["search_docs", "fetch_doc"]
    }
  }
}
```

> config.yml

```yaml title="config.yml – strands MCP" showLineNumbers
mcp_servers:
  strands_mcp:
    transport: "stdio"
    command: "uvx"
    args: ["strands-agents-mcp-server"]
    env:
      FASTMCP_LOG_LEVEL: "INFO"
```


### MCP Aliases

You can define aliases for your MCP servers in the `litellm_settings` section. This allows you to:

1. **Map friendly names to server names**: Use shorter, more memorable aliases
2. **Override server aliases**: If a server doesn't have an alias defined, the system will use the first matching alias from `mcp_aliases`
3. **Ensure uniqueness**: Only the first alias for each server is used, preventing conflicts

**Example:**
```yaml
litellm_settings:
  mcp_aliases:
    "github": "github_mcp_server"      # Maps "github" alias to "github_mcp_server"
    "zapier": "zapier_mcp_server"      # Maps "zapier" alias to "zapier_mcp_server"
    "docs": "deepwiki_mcp_server"      # Maps "docs" alias to "deepwiki_mcp_server"
    "github_alt": "github_mcp_server"  # This will be ignored since "github" already maps to this server
```

**Benefits:**
- **Simplified tool access**: Use `github_create_issue` instead of `github_mcp_server_create_issue`
- **Consistent naming**: Standardize alias patterns across your organization
- **Easy migration**: Change server names without breaking existing tool references

</TabItem>
</Tabs>


## Converting OpenAPI Specs to MCP Servers

LiteLLM can automatically convert OpenAPI specifications into MCP servers, allowing you to expose any REST API as MCP tools. This is useful when you have existing APIs with OpenAPI/Swagger documentation and want to make them available as MCP tools.

**Benefits:**

- **Rapid Integration**: Convert existing APIs to MCP tools without writing custom MCP server code
- **Automatic Tool Generation**: LiteLLM automatically generates MCP tools from your OpenAPI spec
- **Unified Interface**: Use the same MCP interface for both native MCP servers and OpenAPI-based APIs
- **Easy Testing**: Test and iterate on API integrations quickly

**Configuration:**

Add your OpenAPI-based MCP server to your `config.yaml`:

```yaml title="config.yaml - OpenAPI to MCP" showLineNumbers
model_list:
  - model_name: gpt-4o
    litellm_params:
      model: openai/gpt-4o
      api_key: sk-xxxxxxx

mcp_servers:
  # OpenAPI Spec Example - Petstore API
  petstore_mcp:
    url: "https://petstore.swagger.io/v2"
    spec_path: "/path/to/openapi.json"
    auth_type: "none"
  
  # OpenAPI Spec with API Key Authentication
  my_api_mcp:
    url: "http://0.0.0.0:8090"
    spec_path: "/path/to/openapi.json"
    auth_type: "api_key"
    auth_value: "your-api-key-here"
  
  # OpenAPI Spec with Bearer Token
  secured_api_mcp:
    url: "https://api.example.com"
    spec_path: "/path/to/openapi.json" 
    auth_type: "bearer_token"
    auth_value: "your-bearer-token"
```

**Configuration Parameters:**

| Parameter | Required | Description |
|-----------|----------|-------------|
| `url` | Yes | The base URL of your API endpoint |
| `spec_path` | Yes | Path or URL to your OpenAPI specification file (JSON or YAML) |
| `auth_type` | No | Authentication type: `none`, `api_key`, `bearer_token`, `basic`, `authorization` |
| `auth_value` | No | Authentication value (required if `auth_type` is set) |
| `authorization_url` | No | For `auth_type: oauth2`. Optional override; if omitted LiteLLM auto-discovers it. |
| `token_url` | No | For `auth_type: oauth2`. Optional override; if omitted LiteLLM auto-discovers it. |
| `registration_url` | No | For `auth_type: oauth2`. Optional override; if omitted LiteLLM auto-discovers it. |
| `scopes` | No | For `auth_type: oauth2`. Optional override; if omitted LiteLLM uses the scopes advertised by the server. |
| `description` | No | Optional description for the MCP server |
| `allowed_tools` | No | List of specific tools to allow (see [MCP Tool Filtering](#mcp-tool-filtering)) |
| `disallowed_tools` | No | List of specific tools to block (see [MCP Tool Filtering](#mcp-tool-filtering)) |

### Usage Example

Once configured, you can use the OpenAPI-based MCP server just like any other MCP server:

<Tabs>
<TabItem value="fastmcp" label="Python FastMCP">

```python title="Using OpenAPI-based MCP Server" showLineNumbers
from fastmcp import Client
import asyncio

# Standard MCP configuration
config = {
    "mcpServers": {
        "petstore": {
            "url": "http://localhost:4000/petstore_mcp/mcp",
            "headers": {
                "x-litellm-api-key": "Bearer sk-1234"
            }
        }
    }
}

# Create a client that connects to the server
client = Client(config)

async def main():
    async with client:
        # List available tools generated from OpenAPI spec
        tools = await client.list_tools()
        print(f"Available tools: {[tool.name for tool in tools]}")

        # Example: Get a pet by ID (from Petstore API)
        response = await client.call_tool(
            name="getpetbyid", 
            arguments={"petId": "1"}
        )
        print(f"Response:\n{response}\n")

        # Example: Find pets by status
        response = await client.call_tool(
            name="findpetsbystatus", 
            arguments={"status": "available"}
        )
        print(f"Response:\n{response}\n")

if __name__ == "__main__":
    asyncio.run(main())
```

</TabItem>

<TabItem value="cursor" label="Cursor IDE">

```json title="Cursor MCP Configuration for OpenAPI Server" showLineNumbers
{
  "mcpServers": {
    "Petstore": {
      "url": "http://localhost:4000/petstore_mcp/mcp",
      "headers": {
        "x-litellm-api-key": "Bearer $LITELLM_API_KEY"
      }
    }
  }
}
```

</TabItem>

<TabItem value="openai" label="OpenAI Responses API">

```bash title="Using OpenAPI MCP Server with OpenAI" showLineNumbers
curl --location 'https://api.openai.com/v1/responses' \
--header 'Content-Type: application/json' \
--header "Authorization: Bearer $OPENAI_API_KEY" \
--data '{
    "model": "gpt-4o",
    "tools": [
        {
            "type": "mcp",
            "server_label": "petstore",
            "server_url": "http://localhost:4000/petstore_mcp/mcp",
            "require_approval": "never",
            "headers": {
                "x-litellm-api-key": "Bearer YOUR_LITELLM_API_KEY"
            }
        }
    ],
    "input": "Find all available pets in the petstore",
    "tool_choice": "required"
}'
```

</TabItem>
</Tabs>

**How It Works**

1. **Spec Loading**: LiteLLM loads your OpenAPI specification from the provided `spec_path`
2. **Tool Generation**: Each API endpoint in the spec becomes an MCP tool
3. **Parameter Mapping**: OpenAPI parameters are automatically mapped to MCP tool parameters
4. **Request Handling**: When a tool is called, LiteLLM converts the MCP request to the appropriate HTTP request
5. **Response Translation**: API responses are converted back to MCP format

**OpenAPI Spec Requirements**

Your OpenAPI specification should follow standard OpenAPI/Swagger conventions:
- **Supported versions**: OpenAPI 3.0.x, OpenAPI 3.1.x, Swagger 2.0
- **Required fields**: `paths`, `info` sections should be properly defined
- **Operation IDs**: Each operation should have a unique `operationId` (this becomes the tool name)
- **Parameters**: Request parameters should be properly documented with types and descriptions

## MCP OAuth

LiteLLM supports OAuth 2.0 for MCP servers -- both interactive (PKCE) flows for user-facing clients and machine-to-machine (M2M) `client_credentials` for backend services.

See the **[MCP OAuth guide](./mcp_oauth.md)** for setup instructions, sequence diagrams, and a test server.

<details>
<summary>Detailed OAuth reference (click to expand)</summary>

LiteLLM v 1.77.6 added support for OAuth 2.0 Client Credentials for MCP servers.

You can configure this either in `config.yaml` or directly from the LiteLLM UI (MCP Servers → Authentication → OAuth).

```yaml
mcp_servers:
  github_mcp:
    url: "https://api.githubcopilot.com/mcp"
    auth_type: oauth2
    client_id: os.environ/GITHUB_OAUTH_CLIENT_ID
    client_secret: os.environ/GITHUB_OAUTH_CLIENT_SECRET
```

[**See Claude Code Tutorial**](./tutorials/claude_responses_api#connecting-mcp-servers)

### How It Works

```mermaid
sequenceDiagram
    participant Browser as User-Agent (Browser)
    participant Client as Client
    participant LiteLLM as LiteLLM Proxy
    participant MCP as MCP Server (Resource Server)
    participant Auth as Authorization Server

    Note over Client,LiteLLM: Step 1 – Resource discovery
    Client->>LiteLLM: GET /.well-known/oauth-protected-resource/{mcp_server_name}/mcp
    LiteLLM->>Client: Return resource metadata

    Note over Client,LiteLLM: Step 2 – Authorization server discovery
    Client->>LiteLLM: GET /.well-known/oauth-authorization-server/{mcp_server_name}
    LiteLLM->>Client: Return authorization server metadata

    Note over Client,Auth: Step 3 – Dynamic client registration
    Client->>LiteLLM: POST /{mcp_server_name}/register
    LiteLLM->>Auth: Forward registration request
    Auth->>LiteLLM: Issue client credentials
    LiteLLM->>Client: Return client credentials

    Note over Client,Browser: Step 4 – User authorization (PKCE)
    Client->>Browser: Open authorization URL + code_challenge + resource
    Browser->>Auth: Authorization request
    Note over Auth: User authorizes
    Auth->>Browser: Redirect with authorization code
    Browser->>LiteLLM: Callback to LiteLLM with code
    LiteLLM->>Browser: Redirect back with authorization code
    Browser->>Client: Callback with authorization code

    Note over Client,Auth: Step 5 – Token exchange
    Client->>LiteLLM: Token request + code_verifier + resource
    LiteLLM->>Auth: Forward token request
    Auth->>LiteLLM: Access (and refresh) token
    LiteLLM->>Client: Return tokens

    Note over Client,MCP: Step 6 – Authenticated MCP call
    Client->>LiteLLM: MCP request with access token + LiteLLM API key
    LiteLLM->>MCP: MCP request with Bearer token
    MCP-->>LiteLLM: MCP response
    LiteLLM-->>Client: Return MCP response
```

**Participants**

- **Client** – The MCP-capable AI agent (e.g., Claude Code, Cursor, or another IDE/agent) that initiates OAuth discovery, authorization, and tool invocations on behalf of the user.
- **LiteLLM Proxy** – Mediates all OAuth discovery, registration, token exchange, and MCP traffic while protecting stored credentials.
- **Authorization Server** – Issues OAuth 2.0 tokens via dynamic client registration, PKCE authorization, and token endpoints.
- **MCP Server (Resource Server)** – The protected MCP endpoint that receives LiteLLM’s authenticated JSON-RPC requests.
- **User-Agent (Browser)** – Temporarily involved so the end user can grant consent during the authorization step.

**Flow Steps**

1. **Resource Discovery**: The client fetches MCP resource metadata from LiteLLM’s `.well-known/oauth-protected-resource` endpoint to understand scopes and capabilities.
2. **Authorization Server Discovery**: The client retrieves the OAuth server metadata (token endpoint, authorization endpoint, supported PKCE methods) through LiteLLM’s `.well-known/oauth-authorization-server` endpoint.
3. **Dynamic Client Registration**: The client registers through LiteLLM, which forwards the request to the authorization server (RFC 7591). If the provider doesn’t support dynamic registration, you can pre-store `client_id`/`client_secret` in LiteLLM (e.g., GitHub MCP) and the flow proceeds the same way.
4. **User Authorization**: The client launches a browser session (with code challenge and resource hints). The user approves access, the authorization server sends the code through LiteLLM back to the client.
5. **Token Exchange**: The client calls LiteLLM with the authorization code, code verifier, and resource. LiteLLM exchanges them with the authorization server and returns the issued access/refresh tokens.
6. **MCP Invocation**: With a valid token, the client sends the MCP JSON-RPC request (plus LiteLLM API key) to LiteLLM, which forwards it to the MCP server and relays the tool response.

See the official [MCP Authorization Flow](https://modelcontextprotocol.io/specification/2025-06-18/basic/authorization#authorization-flow-steps) for additional reference.

</details>


## Forwarding Custom Headers to MCP Servers

LiteLLM supports forwarding additional custom headers from MCP clients to backend MCP servers using the `extra_headers` configuration parameter. This allows you to pass custom authentication tokens, API keys, or other headers that your MCP server requires.

**Configuration**


<Tabs>
<TabItem value="config" label="config.yaml">
Configure `extra_headers` in your MCP server configuration to specify which header names should be forwarded:

```yaml title="config.yaml with extra_headers" showLineNumbers
mcp_servers:
  github_mcp:
    url: "https://api.githubcopilot.com/mcp"
    auth_type: "bearer_token"
    auth_value: "ghp_default_token"
    extra_headers: ["custom_key", "x-custom-header", "Authorization"]
    description: "GitHub MCP server with custom header forwarding"
```
</TabItem>
<TabItem value="clientside" label="Dynamically on Client Side">

Use this when giving users access to a [group of MCP servers](#grouping-mcps-access-groups).

**Format:** `x-mcp-{server_alias}-{header_name}: value`

This allows you to use different authentication for different MCP servers.


**Examples:**
- `x-mcp-github-authorization: Bearer ghp_xxxxxxxxx` - GitHub MCP server with Bearer token
- `x-mcp-zapier-x-api-key: sk-xxxxxxxxx` - Zapier MCP server with API key
- `x-mcp-deepwiki-authorization: Basic base64_encoded_creds` - DeepWiki MCP server with Basic auth

```python title="Python Client with Server-Specific Auth" showLineNumbers
from fastmcp import Client
import asyncio

# Standard MCP configuration with multiple servers
config = {
    "mcpServers": {
        "mcp_group": {
            "url": "http://localhost:4000/mcp/",
            "headers": {
                "x-mcp-servers": "dev_group", # assume this gives access to github, zapier and deepwiki
                "x-litellm-api-key": "Bearer sk-1234",
                "x-mcp-github-authorization": "Bearer gho_token", 
                "x-mcp-zapier-x-api-key": "sk-xxxxxxxxx",
                "x-mcp-deepwiki-authorization": "Basic base64_encoded_creds",
                "custom_key": "value"
            }
        }
    }
}

# Create a client that connects to all servers
client = Client(config)


async def main():
    async with client:
        tools = await client.list_tools()
        print(f"Available tools: {tools}")

        # call mcp 
        await client.call_tool(
            name="github_mcp-search_issues",
            arguments={'query': 'created:>2024-01-01', 'sort': 'created', 'order': 'desc', 'perPage': 30}
        )

if __name__ == "__main__":
    asyncio.run(main())

```



**Benefits:**
- **Server-specific authentication**: Each MCP server can use different auth methods
- **Better security**: No need to share the same auth token across all servers
- **Flexible header names**: Support for different auth header types (authorization, x-api-key, etc.)
- **Clean separation**: Each server's auth is clearly identified



</TabItem>
</Tabs>


#### Client Usage

When connecting from MCP clients, include the custom headers that match the `extra_headers` configuration:

<Tabs>
<TabItem value="fastmcp" label="Python FastMCP">

```python title="FastMCP Client with Custom Headers" showLineNumbers
from fastmcp import Client
import asyncio

# MCP client configuration with custom headers
config = {
    "mcpServers": {
        "github": {
            "url": "http://localhost:4000/github_mcp/mcp",
            "headers": {
                "x-litellm-api-key": "Bearer sk-1234",
                "Authorization": "Bearer gho_token", 
                "custom_key": "custom_value",
                "x-custom-header": "additional_data"
            }
        }
    }
}

# Create a client that connects to the server
client = Client(config)

async def main():
    async with client:
        # List available tools
        tools = await client.list_tools()
        print(f"Available tools: {tools}")
        
        # Call a tool if available
        if tools:
            result = await client.call_tool(tools[0].name, {})
            print(f"Tool result: {result}")

# Run the client
asyncio.run(main())
```

</TabItem>

<TabItem value="cursor" label="Cursor IDE">

```json title="Cursor MCP Configuration with Custom Headers" showLineNumbers
{
  "mcpServers": {
    "GitHub": {
      "url": "http://localhost:4000/github_mcp/mcp",
      "headers": {
        "x-litellm-api-key": "Bearer $LITELLM_API_KEY",
        "Authorization": "Bearer $GITHUB_TOKEN",
        "custom_key": "custom_value",
        "x-custom-header": "additional_data"
      }
    }
  }
}
```

</TabItem>

<TabItem value="http" label="HTTP Client">

```bash title="cURL with Custom Headers" showLineNumbers
curl --location 'http://localhost:4000/github_mcp/mcp' \
--header 'Content-Type: application/json' \
--header 'x-litellm-api-key: Bearer sk-1234' \
--header 'Authorization: Bearer gho_token' \
--header 'custom_key: custom_value' \
--header 'x-custom-header: additional_data' \
--data '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/list"
}'
```

</TabItem>
</Tabs>

#### How It Works

1. **Configuration**: Define `extra_headers` in your MCP server config with the header names you want to forward
2. **Client Headers**: Include the corresponding headers in your MCP client requests
3. **Header Forwarding**: LiteLLM automatically forwards matching headers to the backend MCP server
4. **Authentication**: The backend MCP server receives both the configured auth headers and the custom headers


### Passing Request Headers to STDIO env Vars

If your stdio MCP server needs per-request credentials, you can map HTTP headers from the client request directly into the environment for the launched stdio process. Reference the header name in the env value using the `${X-HEADER_NAME}` syntax. LiteLLM will read that header from the incoming request and set the env var before starting the command.

```json title="Forward X-GITHUB_PERSONAL_ACCESS_TOKEN header to stdio env" showLineNumbers
{
  "mcpServers": {
    "github": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "GITHUB_PERSONAL_ACCESS_TOKEN",
        "ghcr.io/github/github-mcp-server"
      ],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "${X-GITHUB_PERSONAL_ACCESS_TOKEN}"
      }
    }
  }
}
```

In this example, when a client makes a request with the `X-GITHUB_PERSONAL_ACCESS_TOKEN` header, the proxy forwards that value into the stdio process as the `GITHUB_PERSONAL_ACCESS_TOKEN` environment variable.

## Control MCP Access for End Users

Control which MCP servers end users of your AI application can access (e.g. users of an internal chat UI). Pass the customer ID in the `x-litellm-end-user-id` header to:
- Enforce object permissions (limit which MCP servers they can access)
- Apply customer-specific budgets
- Track spend per customer

**FastMCP Client Example:**

```python title="Track customer spend with x-litellm-end-user-id" showLineNumbers
from fastmcp import Client
import asyncio

# MCP client configuration with customer tracking
config = {
    "mcpServers": {
        "github": {
            "url": "http://localhost:4000/github_mcp/mcp",
            "headers": {
                "x-litellm-api-key": "Bearer sk-1234",
                "x-litellm-end-user-id": "customer_123",  # 👈 CUSTOMER ID
                "Authorization": "Bearer gho_token"
            }
        }
    }
}

client = Client(config)

async def main():
    async with client:
        # All MCP calls will be tracked under customer_123
        tools = await client.list_tools()
        result = await client.call_tool(tools[0].name, {})
        print(f"Tool result: {result}")

asyncio.run(main())
```

**Cursor IDE Example:**

```json title="Cursor config with customer tracking" showLineNumbers
{
  "mcpServers": {
    "GitHub": {
      "url": "http://localhost:4000/github_mcp/mcp",
      "headers": {
        "x-litellm-api-key": "Bearer $LITELLM_API_KEY",
        "x-litellm-end-user-id": "customer_123"
      }
    }
  }
}
```

**What happens:**
- Customer-specific object permissions are enforced (only allowed MCP servers are accessible)
- Customer budgets are applied
- All tool calls are tracked under `customer_123`

[Learn more about customer management →](./proxy/customers)

## Using your MCP with client side credentials

Use this if you want to pass a client side authentication token to LiteLLM to then pass to your MCP to auth to your MCP.


### New Server-Specific Auth Headers (Recommended)

You can specify MCP auth tokens using server-specific headers in the format `x-mcp-{server_alias}-{header_name}`. This allows you to use different authentication for different MCP servers.

**Benefits:**
- **Server-specific authentication**: Each MCP server can use different auth methods
- **Better security**: No need to share the same auth token across all servers
- **Flexible header names**: Support for different auth header types (authorization, x-api-key, etc.)
- **Clean separation**: Each server's auth is clearly identified

### Legacy Auth Header (Deprecated)

You can also specify your MCP auth token using the header `x-mcp-auth`. This will be forwarded to all MCP servers and is deprecated in favor of server-specific headers.

<Tabs>
<TabItem value="openai" label="OpenAI API">

#### Connect via OpenAI Responses API with Server-Specific Auth

Use the OpenAI Responses API and include server-specific auth headers:

```bash title="cURL Example with Server-Specific Auth" showLineNumbers
curl --location 'https://api.openai.com/v1/responses' \
--header 'Content-Type: application/json' \
--header "Authorization: Bearer $OPENAI_API_KEY" \
--data '{
    "model": "gpt-4o",
    "tools": [
        {
            "type": "mcp",
            "server_label": "litellm",
            "server_url": "litellm_proxy",
            "require_approval": "never",
            "headers": {
                "x-litellm-api-key": "Bearer YOUR_LITELLM_API_KEY",
                "x-mcp-github-authorization": "Bearer YOUR_GITHUB_TOKEN",
                "x-mcp-zapier-x-api-key": "YOUR_ZAPIER_API_KEY"
            }
        }
    ],
    "input": "Run available tools",
    "tool_choice": "required"
}'
```

#### Connect via OpenAI Responses API with Legacy Auth

Use the OpenAI Responses API and include the `x-mcp-auth` header for your MCP server authentication:

```bash title="cURL Example with Legacy MCP Auth" showLineNumbers
curl --location 'https://api.openai.com/v1/responses' \
--header 'Content-Type: application/json' \
--header "Authorization: Bearer $OPENAI_API_KEY" \
--data '{
    "model": "gpt-4o",
    "tools": [
        {
            "type": "mcp",
            "server_label": "litellm",
            "server_url": "litellm_proxy",
            "require_approval": "never",
            "headers": {
                "x-litellm-api-key": "Bearer YOUR_LITELLM_API_KEY",
                "x-mcp-auth": YOUR_MCP_AUTH_TOKEN
            }
        }
    ],
    "input": "Run available tools",
    "tool_choice": "required"
}'
```

</TabItem>

<TabItem value="litellm" label="LiteLLM Proxy">

#### Connect via LiteLLM Proxy Responses API with Server-Specific Auth

Use this when calling LiteLLM Proxy for LLM API requests to `/v1/responses` endpoint with server-specific authentication:

```bash title="cURL Example with Server-Specific Auth" showLineNumbers
curl --location '<your-litellm-proxy-base-url>/v1/responses' \
--header 'Content-Type: application/json' \
--header "Authorization: Bearer $LITELLM_API_KEY" \
--data '{
    "model": "gpt-4o",
    "tools": [
        {
            "type": "mcp",
            "server_label": "litellm",
            "server_url": "litellm_proxy",
            "require_approval": "never",
            "headers": {
                "x-litellm-api-key": "Bearer YOUR_LITELLM_API_KEY",
                "x-mcp-github-authorization": "Bearer YOUR_GITHUB_TOKEN",
                "x-mcp-zapier-x-api-key": "YOUR_ZAPIER_API_KEY"
            }
        }
    ],
    "input": "Run available tools",
    "tool_choice": "required"
}'
```

#### Connect via LiteLLM Proxy Responses API with Legacy Auth

Use this when calling LiteLLM Proxy for LLM API requests to `/v1/responses` endpoint with MCP authentication:

```bash title="cURL Example with Legacy MCP Auth" showLineNumbers
curl --location '<your-litellm-proxy-base-url>/v1/responses' \
--header 'Content-Type: application/json' \
--header "Authorization: Bearer $LITELLM_API_KEY" \
--data '{
    "model": "gpt-4o",
    "tools": [
        {
            "type": "mcp",
            "server_label": "litellm",
            "server_url": "litellm_proxy",
            "require_approval": "never",
            "headers": {
                "x-litellm-api-key": "Bearer YOUR_LITELLM_API_KEY",
                "x-mcp-auth": "YOUR_MCP_AUTH_TOKEN"
            }
        }
    ],
    "input": "Run available tools",
    "tool_choice": "required"
}'
```

</TabItem>

<TabItem value="cursor" label="Cursor IDE">

#### Connect via Cursor IDE with Server-Specific Auth

Use tools directly from Cursor IDE with LiteLLM MCP and include server-specific authentication:

**Setup Instructions:**

1. **Open Cursor Settings**: Use `⇧+⌘+J` (Mac) or `Ctrl+Shift+J` (Windows/Linux)
2. **Navigate to MCP Tools**: Go to the "MCP Tools" tab and click "New MCP Server"
3. **Add Configuration**: Copy and paste the JSON configuration below, then save with `Cmd+S` or `Ctrl+S`

```json title="Cursor MCP Configuration with Server-Specific Auth" showLineNumbers
{
  "mcpServers": {
    "LiteLLM": {
      "url": "litellm_proxy",
      "headers": {
        "x-litellm-api-key": "Bearer $LITELLM_API_KEY",
        "x-mcp-github-authorization": "Bearer $GITHUB_TOKEN",
        "x-mcp-zapier-x-api-key": "$ZAPIER_API_KEY"
      }
    }
  }
}
```

#### Connect via Cursor IDE with Legacy Auth

Use tools directly from Cursor IDE with LiteLLM MCP and include your MCP authentication token:

**Setup Instructions:**

1. **Open Cursor Settings**: Use `⇧+⌘+J` (Mac) or `Ctrl+Shift+J` (Windows/Linux)
2. **Navigate to MCP Tools**: Go to the "MCP Tools" tab and click "New MCP Server"
3. **Add Configuration**: Copy and paste the JSON configuration below, then save with `Cmd+S` or `Ctrl+S`

```json title="Cursor MCP Configuration with Legacy Auth" showLineNumbers
{
  "mcpServers": {
    "LiteLLM": {
      "url": "litellm_proxy",
      "headers": {
        "x-litellm-api-key": "Bearer $LITELLM_API_KEY",
        "x-mcp-auth": "$MCP_AUTH_TOKEN"
      }
    }
  }
}
```

</TabItem>

<TabItem value="http" label="Streamable HTTP">

#### Connect via Streamable HTTP Transport with Server-Specific Auth

Connect to LiteLLM MCP using HTTP transport with server-specific authentication:

**Server URL:**
```text showLineNumbers
litellm_proxy
```

**Headers:**
```text showLineNumbers
x-litellm-api-key: Bearer YOUR_LITELLM_API_KEY
x-mcp-github-authorization: Bearer YOUR_GITHUB_TOKEN
x-mcp-zapier-x-api-key: YOUR_ZAPIER_API_KEY
```

#### Connect via Streamable HTTP Transport with Legacy Auth

Connect to LiteLLM MCP using HTTP transport with MCP authentication:

**Server URL:**
```text showLineNumbers
litellm_proxy
```

**Headers:**
```text showLineNumbers
x-litellm-api-key: Bearer YOUR_LITELLM_API_KEY
x-mcp-auth: Bearer YOUR_MCP_AUTH_TOKEN
```

This URL can be used with any MCP client that supports HTTP transport. The `x-mcp-auth` header will be forwarded to your MCP server for authentication.

</TabItem>

<TabItem value="fastmcp" label="Python FastMCP">

#### Connect via Python FastMCP Client with Server-Specific Auth

Use the Python FastMCP client to connect to your LiteLLM MCP server with server-specific authentication:

```python title="Python FastMCP Example with Server-Specific Auth" showLineNumbers
import asyncio
import json

from fastmcp import Client
from fastmcp.client.transports import StreamableHttpTransport

# Create the transport with your LiteLLM MCP server URL and server-specific auth headers
server_url = "litellm_proxy"
transport = StreamableHttpTransport(
    server_url,
    headers={
        "x-litellm-api-key": "Bearer YOUR_LITELLM_API_KEY",
        "x-mcp-github-authorization": "Bearer YOUR_GITHUB_TOKEN",
        "x-mcp-zapier-x-api-key": "YOUR_ZAPIER_API_KEY"
    }
)

# Initialize the client with the transport
client = Client(transport=transport)


async def main():
    # Connection is established here
    print("Connecting to LiteLLM MCP server with server-specific authentication...")
    async with client:
        print(f"Client connected: {client.is_connected()}")

        # Make MCP calls within the context
        print("Fetching available tools...")
        tools = await client.list_tools()

        print(f"Available tools: {json.dumps([t.name for t in tools], indent=2)}")
        
        # Example: Call a tool (replace 'tool_name' with an actual tool name)
        if tools:
            tool_name = tools[0].name
            print(f"Calling tool: {tool_name}")
            
            # Call the tool with appropriate arguments
            result = await client.call_tool(tool_name, arguments={})
            print(f"Tool result: {result}")


# Run the example
if __name__ == "__main__":
    asyncio.run(main())
```

#### Connect via Python FastMCP Client with Legacy Auth

Use the Python FastMCP client to connect to your LiteLLM MCP server with MCP authentication:

```python title="Python FastMCP Example with Legacy MCP Auth" showLineNumbers
import asyncio
import json

from fastmcp import Client
from fastmcp.client.transports import StreamableHttpTransport

# Create the transport with your LiteLLM MCP server URL and auth headers
server_url = "litellm_proxy"
transport = StreamableHttpTransport(
    server_url,
    headers={
        "x-litellm-api-key": "Bearer YOUR_LITELLM_API_KEY",
        "x-mcp-auth": "Bearer YOUR_MCP_AUTH_TOKEN"
    }
)

# Initialize the client with the transport
client = Client(transport=transport)


async def main():
    # Connection is established here
    print("Connecting to LiteLLM MCP server with authentication...")
    async with client:
        print(f"Client connected: {client.is_connected()}")

        # Make MCP calls within the context
        print("Fetching available tools...")
        tools = await client.list_tools()

        print(f"Available tools: {json.dumps([t.name for t in tools], indent=2)}")
        
        # Example: Call a tool (replace 'tool_name' with an actual tool name)
        if tools:
            tool_name = tools[0].name
            print(f"Calling tool: {tool_name}")
            
            # Call the tool with appropriate arguments
            result = await client.call_tool(tool_name, arguments={})
            print(f"Tool result: {result}")


# Run the example
if __name__ == "__main__":
    asyncio.run(main())
```

</TabItem>
</Tabs>

### Customize the MCP Auth Header Name

By default, LiteLLM uses `x-mcp-auth` to pass your credentials to MCP servers. You can change this header name in one of the following ways:
1. Set the `LITELLM_MCP_CLIENT_SIDE_AUTH_HEADER_NAME` environment variable

```bash title="Environment Variable" showLineNumbers
export LITELLM_MCP_CLIENT_SIDE_AUTH_HEADER_NAME="authorization"
```


2. Set the `mcp_client_side_auth_header_name` in the general settings on the config.yaml file

```yaml title="config.yaml" showLineNumbers
model_list:
  - model_name: gpt-4o
    litellm_params:
      model: openai/gpt-4o
      api_key: sk-xxxxxxx

general_settings:
  mcp_client_side_auth_header_name: "authorization"
```

#### Using the authorization header

In this example the `authorization` header will be passed to the MCP server for authentication.

```bash title="cURL with authorization header" showLineNumbers
curl --location '<your-litellm-proxy-base-url>/v1/responses' \
--header 'Content-Type: application/json' \
--header "Authorization: Bearer $LITELLM_API_KEY" \
--data '{
    "model": "gpt-4o",
    "tools": [
        {
            "type": "mcp",
            "server_label": "litellm",
            "server_url": "litellm_proxy",
            "require_approval": "never",
            "headers": {
                "x-litellm-api-key": "Bearer YOUR_LITELLM_API_KEY",
                "authorization": "Bearer sk-zapier-token-123"
            }
        }
    ],
    "input": "Run available tools",
    "tool_choice": "required"
}'
```

## Use MCP tools with `/chat/completions`

:::tip Works with all providers
This flow is **provider-agnostic**: the same MCP tool definition works for _every_ LLM backend behind LiteLLM (OpenAI, Azure OpenAI, Anthropic, Amazon Bedrock, Vertex, self-hosted deployments, etc.).
:::

LiteLLM Proxy also supports MCP-aware tooling on the classic `/v1/chat/completions` endpoint. Provide the MCP tool definition directly in the `tools` array and LiteLLM will fetch and transform the MCP server's tools into OpenAI-compatible function calls. When `require_approval` is set to `"never"`, the proxy automatically executes the returned tool calls and feeds the results back into the model before returning the assistant response.

```bash title="Chat Completions with MCP Tools" showLineNumbers
curl --location '<your-litellm-proxy-base-url>/v1/chat/completions' \
--header 'Content-Type: application/json' \
--header "Authorization: Bearer $LITELLM_API_KEY" \
--data '{
  "model": "gpt-4o-mini",
  "messages": [
    {"role": "user", "content": "Summarize the latest open PR."}
  ],
  "tools": [
    {
      "type": "mcp",
      "server_url": "litellm_proxy/mcp/github",
      "server_label": "github_mcp",
      "require_approval": "never"
    }
  ]
}'
```

If you omit `require_approval` or set it to any value other than `"never"`, the MCP tool calls are returned to the client so that you can review and execute them manually, matching the upstream OpenAI behavior.


## LiteLLM Proxy - Walk through MCP Gateway
LiteLLM exposes an MCP Gateway for admins to add all their MCP servers to LiteLLM. The key benefits of using LiteLLM Proxy with MCP are:

1. Use a fixed endpoint for all MCP tools
2. MCP Permission management by Key, Team, or User

This video demonstrates how you can onboard an MCP server to LiteLLM Proxy, use it and set access controls.

<iframe width="840" height="500" src="https://www.loom.com/embed/f7aa8d217879430987f3e64291757bfc" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>

## LiteLLM Python SDK MCP Bridge

LiteLLM Python SDK acts as a MCP bridge to utilize MCP tools with all LiteLLM supported models. LiteLLM offers the following features for using MCP

- **List** Available MCP Tools: OpenAI clients can view all available MCP tools
  - `litellm.experimental_mcp_client.load_mcp_tools` to list all available MCP tools
- **Call** MCP Tools: OpenAI clients can call MCP tools
  - `litellm.experimental_mcp_client.call_openai_tool` to call an OpenAI tool on an MCP server


### 1. List Available MCP Tools

In this example we'll use `litellm.experimental_mcp_client.load_mcp_tools` to list all available MCP tools on any MCP server. This method can be used in two ways:

- `format="mcp"` - (default) Return MCP tools 
  - Returns: `mcp.types.Tool`
- `format="openai"` - Return MCP tools converted to OpenAI API compatible tools. Allows using with OpenAI endpoints.
  - Returns: `openai.types.chat.ChatCompletionToolParam`

<Tabs>
<TabItem value="sdk" label="LiteLLM Python SDK">

```python title="MCP Client List Tools" showLineNumbers
# Create server parameters for stdio connection
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client
import os
import litellm
from litellm import experimental_mcp_client


server_params = StdioServerParameters(
    command="python3",
    # Make sure to update to the full absolute path to your mcp_server.py file
    args=["./mcp_server.py"],
)

async with stdio_client(server_params) as (read, write):
    async with ClientSession(read, write) as session:
        # Initialize the connection
        await session.initialize()

        # Get tools
        tools = await experimental_mcp_client.load_mcp_tools(session=session, format="openai")
        print("MCP TOOLS: ", tools)

        messages = [{"role": "user", "content": "what's (3 + 5)"}]
        llm_response = await litellm.acompletion(
            model="gpt-4o",
            api_key=os.getenv("OPENAI_API_KEY"),
            messages=messages,
            tools=tools,
        )
        print("LLM RESPONSE: ", json.dumps(llm_response, indent=4, default=str))
```

</TabItem>

<TabItem value="openai" label="OpenAI SDK + LiteLLM Proxy">

In this example we'll walk through how you can use the OpenAI SDK pointed to the LiteLLM proxy to call MCP tools. The key difference here is we use the OpenAI SDK to make the LLM API request

```python title="MCP Client List Tools" showLineNumbers
# Create server parameters for stdio connection
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client
import os
from openai import OpenAI
from litellm import experimental_mcp_client

server_params = StdioServerParameters(
    command="python3",
    # Make sure to update to the full absolute path to your mcp_server.py file
    args=["./mcp_server.py"],
)

async with stdio_client(server_params) as (read, write):
    async with ClientSession(read, write) as session:
        # Initialize the connection
        await session.initialize()

        # Get tools using litellm mcp client
        tools = await experimental_mcp_client.load_mcp_tools(session=session, format="openai")
        print("MCP TOOLS: ", tools)

        # Use OpenAI SDK pointed to LiteLLM proxy
        client = OpenAI(
            api_key="your-api-key",  # Your LiteLLM proxy API key
            base_url="http://localhost:4000"  # Your LiteLLM proxy URL
        )

        messages = [{"role": "user", "content": "what's (3 + 5)"}]
        llm_response = client.chat.completions.create(
            model="gpt-4",
            messages=messages,
            tools=tools
        )
        print("LLM RESPONSE: ", llm_response)
```
</TabItem>
</Tabs>


### 2. List and Call MCP Tools

In this example we'll use 
- `litellm.experimental_mcp_client.load_mcp_tools` to list all available MCP tools on any MCP server
- `litellm.experimental_mcp_client.call_openai_tool` to call an OpenAI tool on an MCP server

The first llm response returns a list of OpenAI tools. We take the first tool call from the LLM response and pass it to `litellm.experimental_mcp_client.call_openai_tool` to call the tool on the MCP server.

#### How `litellm.experimental_mcp_client.call_openai_tool` works

- Accepts an OpenAI Tool Call from the LLM response
- Converts the OpenAI Tool Call to an MCP Tool
- Calls the MCP Tool on the MCP server
- Returns the result of the MCP Tool call

<Tabs>
<TabItem value="sdk" label="LiteLLM Python SDK">

```python title="MCP Client List and Call Tools" showLineNumbers
# Create server parameters for stdio connection
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client
import os
import litellm
from litellm import experimental_mcp_client


server_params = StdioServerParameters(
    command="python3",
    # Make sure to update to the full absolute path to your mcp_server.py file
    args=["./mcp_server.py"],
)

async with stdio_client(server_params) as (read, write):
    async with ClientSession(read, write) as session:
        # Initialize the connection
        await session.initialize()

        # Get tools
        tools = await experimental_mcp_client.load_mcp_tools(session=session, format="openai")
        print("MCP TOOLS: ", tools)

        messages = [{"role": "user", "content": "what's (3 + 5)"}]
        llm_response = await litellm.acompletion(
            model="gpt-4o",
            api_key=os.getenv("OPENAI_API_KEY"),
            messages=messages,
            tools=tools,
        )
        print("LLM RESPONSE: ", json.dumps(llm_response, indent=4, default=str))

        openai_tool = llm_response["choices"][0]["message"]["tool_calls"][0]
        # Call the tool using MCP client
        call_result = await experimental_mcp_client.call_openai_tool(
            session=session,
            openai_tool=openai_tool,
        )
        print("MCP TOOL CALL RESULT: ", call_result)

        # send the tool result to the LLM
        messages.append(llm_response["choices"][0]["message"])
        messages.append(
            {
                "role": "tool",
                "content": str(call_result.content[0].text),
                "tool_call_id": openai_tool["id"],
            }
        )
        print("final messages with tool result: ", messages)
        llm_response = await litellm.acompletion(
            model="gpt-4o",
            api_key=os.getenv("OPENAI_API_KEY"),
            messages=messages,
            tools=tools,
        )
        print(
            "FINAL LLM RESPONSE: ", json.dumps(llm_response, indent=4, default=str)
        )
```

</TabItem>
<TabItem value="proxy" label="OpenAI SDK + LiteLLM Proxy">

In this example we'll walk through how you can use the OpenAI SDK pointed to the LiteLLM proxy to call MCP tools. The key difference here is we use the OpenAI SDK to make the LLM API request

```python title="MCP Client with OpenAI SDK" showLineNumbers
# Create server parameters for stdio connection
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client
import os
from openai import OpenAI
from litellm import experimental_mcp_client

server_params = StdioServerParameters(
    command="python3",
    # Make sure to update to the full absolute path to your mcp_server.py file
    args=["./mcp_server.py"],
)

async with stdio_client(server_params) as (read, write):
    async with ClientSession(read, write) as session:
        # Initialize the connection
        await session.initialize()

        # Get tools using litellm mcp client
        tools = await experimental_mcp_client.load_mcp_tools(session=session, format="openai")
        print("MCP TOOLS: ", tools)

        # Use OpenAI SDK pointed to LiteLLM proxy
        client = OpenAI(
            api_key="your-api-key",  # Your LiteLLM proxy API key
            base_url="http://localhost:8000"  # Your LiteLLM proxy URL
        )

        messages = [{"role": "user", "content": "what's (3 + 5)"}]
        llm_response = client.chat.completions.create(
            model="gpt-4",
            messages=messages,
            tools=tools
        )
        print("LLM RESPONSE: ", llm_response)

        # Get the first tool call
        tool_call = llm_response.choices[0].message.tool_calls[0]
        
        # Call the tool using MCP client
        call_result = await experimental_mcp_client.call_openai_tool(
            session=session,
            openai_tool=tool_call.model_dump(),
        )
        print("MCP TOOL CALL RESULT: ", call_result)

        # Send the tool result back to the LLM
        messages.append(llm_response.choices[0].message.model_dump())
        messages.append({
            "role": "tool",
            "content": str(call_result.content[0].text),
            "tool_call_id": tool_call.id,
        })

        final_response = client.chat.completions.create(
            model="gpt-4",
            messages=messages,
            tools=tools
        )
        print("FINAL RESPONSE: ", final_response)
```

</TabItem>
</Tabs>

## FAQ

**Q: How do I use OAuth2 client_credentials (machine-to-machine) with MCP servers behind LiteLLM?**

LiteLLM supports automatic token management for the `client_credentials` grant. Configure `client_id`, `client_secret`, and `token_url` on your MCP server and LiteLLM will fetch, cache, and refresh tokens automatically. See the [MCP OAuth M2M guide](./mcp_oauth.md#machine-to-machine-m2m-auth) for setup instructions.

**Q: When I fetch an OAuth token from the LiteLLM UI, where is it stored?**

The UI keeps only transient state in `sessionStorage` so the OAuth redirect flow can finish; the token is not persisted in the server or database.

**Q: I'm seeing MCP connection errors—what should I check?**

Walk through the [MCP Troubleshooting Guide](./mcp_troubleshoot.md) for step-by-step isolation (Client → LiteLLM vs. LiteLLM → MCP), log examples, and verification methods like MCP Inspector and `curl`.