Implementation:BerriAI Litellm MCP Client

Property	Value
sources	litellm/experimental_mcp_client/client.py
domains	MCP, Model Context Protocol, Tool Calling, SSE, HTTP
last_updated	2026-02-15 16:00 GMT

Overview

The MCP Client module implements a Model Context Protocol (MCP) client that connects to MCP servers, supporting SSE, HTTP (streamable), and stdio transports with multiple authentication methods, and provides methods for listing tools, calling tools, managing prompts, and reading resources.

Description

The MCPClient class manages connections to MCP servers through three transport types: SSE (sse_client), HTTP (streamable_http_client), and stdio (stdio_client). Authentication supports five types: bearer token, basic auth, API key, raw authorization header, and OAuth2. The client follows a session-per-operation pattern via run_with_session(), which creates a transport context, initializes a ClientSession, runs the operation, and cleans up resources. Each public method (list_tools, call_tool, list_prompts, get_prompt, list_resources, list_resource_templates, read_resource) opens a new session for the operation. The client includes graceful degradation: list_tools, list_prompts, list_resources, and list_resource_templates return empty lists on failure, while call_tool returns an error result with isError=True. SSL configuration follows LiteLLM's standard SSL handling via get_ssl_configuration(). Tool call progress is reported through an optional callback.

Usage

Import this module when you need to connect to MCP servers for tool discovery and execution. It is used internally by the Responses API when MCP tools with server_url are detected, and can be used directly for standalone MCP interactions.

Code Reference

Source Location

Property	Value
Repository	github.com/BerriAI/litellm
File	litellm/experimental_mcp_client/client.py
Lines	587
Module	litellm.experimental_mcp_client.client

Signature

class MCPClient:
    def __init__(
        self,
        server_url: str = "",
        transport_type: MCPTransportType = MCPTransport.http,
        auth_type: MCPAuthType = None,
        auth_value: Optional[Union[str, Dict[str, str]]] = None,
        timeout: float = 60.0,
        stdio_config: Optional[MCPStdioConfig] = None,
        extra_headers: Optional[Dict[str, str]] = None,
        ssl_verify: Optional[VerifyTypes] = None,
    )

    async def list_tools(self) -> List[MCPTool]
    async def call_tool(
        self,
        call_tool_request_params: MCPCallToolRequestParams,
        host_progress_callback: Optional[Callable] = None,
    ) -> MCPCallToolResult
    async def list_prompts(self) -> List[Prompt]
    async def get_prompt(self, get_prompt_request_params: GetPromptRequestParams) -> GetPromptResult
    async def list_resources(self) -> list[Resource]
    async def list_resource_templates(self) -> list[ResourceTemplate]
    async def read_resource(self, url: AnyUrl) -> ReadResourceResult

Import

from litellm.experimental_mcp_client.client import MCPClient

I/O Contract

Inputs

Parameter	Type	Required	Description
server_url	str	For SSE/HTTP	The URL of the MCP server
transport_type	MCPTransportType	No	Transport: MCPTransport.http (default), .sse, or .stdio
auth_type	MCPAuthType	No	Authentication type: bearer_token, basic, api_key, authorization, oauth2
auth_value	Optional[Union[str, Dict]]	No	Authentication credentials
timeout	float	No	Request timeout in seconds (default: 60.0)
stdio_config	Optional[MCPStdioConfig]	For stdio	Configuration for stdio transport (command, args, env)
ssl_verify	Optional[VerifyTypes]	No	SSL verification setting (bool, path, or SSLContext)

Outputs

Method	Return Type	Description
list_tools	List[MCPTool]	Available tools from the MCP server (empty list on failure)
call_tool	MCPCallToolResult	Tool execution result (error result on failure)
list_prompts	List[Prompt]	Available prompts from the MCP server
get_prompt	GetPromptResult	A specific prompt definition
list_resources	list[Resource]	Available resources from the MCP server
read_resource	ReadResourceResult	Contents of a specific resource

Usage Examples

from litellm.experimental_mcp_client.client import MCPClient
from litellm.types.mcp import MCPTransport, MCPAuth

# Create an MCP client with HTTP transport and bearer auth
client = MCPClient(
    server_url="https://mcp-server.example.com",
    transport_type=MCPTransport.http,
    auth_type=MCPAuth.bearer_token,
    auth_value="your-api-key",
)

# List available tools
tools = await client.list_tools()
for tool in tools:
    print(f"Tool: {tool.name} - {tool.description}")

from mcp.types import CallToolRequestParams

# Call a tool
result = await client.call_tool(
    call_tool_request_params=CallToolRequestParams(
        name="search",
        arguments={"query": "LiteLLM documentation"},
    )
)
if not result.isError:
    for content in result.content:
        print(content.text)

Related Pages

• BerriAI_Litellm_Responses_API -- Uses this MCP client when MCP tools are detected in response requests
• BerriAI_Litellm_Assistants_API -- Assistants API that can leverage MCP tools indirectly through the Responses API