Simple Auth Client Example

A demonstration of how to use the MCP Python SDK with OAuth authentication over streamable HTTP or SSE transport.

Features

OAuth 2.0 authentication with PKCE
Support for both StreamableHTTP and SSE transports
Interactive command-line interface

Installation

bash

cd examples/clients/simple-auth-client
uv sync --reinstall

Usage

1. Start an MCP server with OAuth support

The simple-auth server example provides three server configurations. See examples/servers/simple-auth/README.md for full details.

Option A: New Architecture (Recommended)

Separate Authorization Server and Resource Server:

bash

# Terminal 1: Start Authorization Server on port 9000
cd examples/servers/simple-auth
uv run mcp-simple-auth-as --port=9000

# Terminal 2: Start Resource Server on port 8001
cd examples/servers/simple-auth
uv run mcp-simple-auth-rs --port=8001 --auth-server=http://localhost:9000 --transport=streamable-http

Option B: Legacy Server (Backwards Compatibility)

bash

# Single server that acts as both AS and RS (port 8000)
cd examples/servers/simple-auth
uv run mcp-simple-auth-legacy --port=8000 --transport=streamable-http

2. Run the client

bash

# Connect to Resource Server (new architecture, default port 8001)
MCP_SERVER_PORT=8001 uv run mcp-simple-auth-client

# Connect to Legacy Server (port 8000)
uv run mcp-simple-auth-client

# Use SSE transport
MCP_SERVER_PORT=8001 MCP_TRANSPORT_TYPE=sse uv run mcp-simple-auth-client

3. Complete OAuth flow

The client will open your browser for authentication. After completing OAuth, you can use commands:

list - List available tools
call <tool_name> [args] - Call a tool with optional JSON arguments
quit - Exit

Example

markdown

🚀 Simple MCP Auth Client
Connecting to: http://localhost:8001/mcp
Transport type: streamable-http

🔗 Attempting to connect to http://localhost:8001/mcp...
📡 Opening StreamableHTTP transport connection with auth...
Opening browser for authorization: http://localhost:9000/authorize?...

✅ Connected to MCP server at http://localhost:8001/mcp

mcp> list
📋 Available tools:
1. get_time
   Description: Get the current server time.

mcp> call get_time
🔧 Tool 'get_time' result:
{"current_time": "2024-01-15T10:30:00", "timezone": "UTC", ...}

mcp> quit

Configuration

Environment Variable	Description	Default
`MCP_SERVER_PORT`	Port number of the MCP server	`8000`
`MCP_TRANSPORT_TYPE`	Transport type: `streamable-http` or `sse`	`streamable-http`
`MCP_CLIENT_METADATA_URL`	Optional URL for client metadata (CIMD)	None