MCP Echo StreamableHTTP Server - Stateless

A stateless diagnostic MCP (Model Context Protocol) server that implements the StreamableHTTP transport specification. This server provides comprehensive debugging tools for MCP protocol development and OAuth authentication flow analysis.

Overview

This is a stateless implementation of an MCP echo server designed specifically for:

• Protocol debugging and validation
• Authentication flow analysis
• System diagnostics and health monitoring
• MCP client integration testing

Unlike the stateful variant, this server maintains no session state between requests, making each request completely independent.

Features

9 Diagnostic Tools

1. echo - Simple message echo for basic connectivity testing
2. printHeader - Displays all HTTP headers organized by category
3. bearerDecode - Decodes JWT Bearer tokens (without verification) for debugging
4. authContext - Provides complete authentication context analysis
5. requestTiming - Shows request performance metrics and system stats
6. corsAnalysis - Analyzes CORS configuration and headers
7. environmentDump - Displays sanitized environment configuration
8. healthProbe - Performs deep health check with system resource monitoring
9. whoIStheGOAT - Easter egg that reveals programming wisdom

Protocol Support

• MCP Protocol Version: 2025-06-18 (configurable)
• Transport: StreamableHTTP with JSON and SSE response formats
• JSON-RPC: 2.0 compliant
• Session Management: Stateless with session ID tracking via headers

Authentication Integration

• Designed to work behind Traefik with ForwardAuth middleware
• Reads authentication headers forwarded by Traefik
• Provides JWT token decoding for debugging (no verification)
• Exposes complete authentication context through diagnostic tools

Installation

Using pip

pip install mcp-echo-streamablehttp-server-stateless

Using pixi

pixi add --pypi mcp-echo-streamablehttp-server-stateless

Docker Deployment

FROM python:3.11-slim

# Install the package
RUN pip install mcp-echo-streamablehttp-server-stateless

# Set environment variables
ENV MCP_ECHO_HOST=0.0.0.0
ENV MCP_ECHO_PORT=3000
ENV MCP_ECHO_DEBUG=false

# Expose the port
EXPOSE 3000

# Run the server
CMD ["python", "-m", "mcp_echo_streamablehttp_server_stateless"]

Configuration

Environment Variables

# Server Configuration
MCP_ECHO_HOST=127.0.0.1          # Server bind address (default: 127.0.0.1)
MCP_ECHO_PORT=3000               # Server port (default: 3000)
MCP_ECHO_DEBUG=false             # Enable debug logging (default: false)

# Protocol Configuration
MCP_PROTOCOL_VERSION=2025-06-18  # Default MCP protocol version
MCP_PROTOCOL_VERSIONS_SUPPORTED=2025-06-18,2024-11-05  # Comma-separated supported versions

# Logging
LOG_FILE=/logs/mcp-echo-stateless.log  # Optional log file path

Docker Compose Integration

services:
  mcp-echo-stateless:
    image: mcp-echo-stateless:latest
    build:
      context: ./mcp-echo-streamablehttp-server-stateless
    environment:
      - MCP_ECHO_HOST=0.0.0.0
      - MCP_ECHO_PORT=3000
      - MCP_ECHO_DEBUG=false
      - MCP_PROTOCOL_VERSION=2025-06-18
    ports:
      - "3000:3000"
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:3000/mcp", "-X", "POST",
             "-H", "Content-Type: application/json",
             "-d", '{"jsonrpc":"2.0","method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"healthcheck","version":"1.0"}},"id":1}']
      interval: 30s
      timeout: 5s
      retries: 3

The service includes comprehensive Docker configuration with:

• Health checks using MCP protocol initialization
• Traefik routing labels with proper priorities
• Integration with the OAuth gateway architecture

Quick Start

Running Locally

# Using pip/pixi installation
mcp-echo-stateless-server

# Or using Python module
python -m mcp_echo_streamablehttp_server_stateless

# With custom configuration
MCP_ECHO_PORT=8080 MCP_ECHO_DEBUG=true mcp-echo-stateless-server

Usage Examples

Testing with Just Commands

# Test basic echo functionality
just test-mcp-tool mcp-echo-stateless echo '{"message": "Hello, World!"}'

# Analyze authentication context
just test-mcp-tool mcp-echo-stateless authContext '{}'

# View all HTTP headers
just test-mcp-tool mcp-echo-stateless printHeader '{}'

# Check system health
just test-mcp-tool mcp-echo-stateless healthProbe '{}'

# Decode a Bearer token
just test-mcp-tool mcp-echo-stateless bearerDecode '{"token": "your-jwt-token-here"}'

Direct API Usage

# Initialize connection
curl -X POST https://mcp-echo-stateless.yourdomain.com/mcp \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -d '{
    "jsonrpc": "2.0",
    "method": "initialize",
    "params": {
      "protocolVersion": "2025-06-18",
      "capabilities": {},
      "clientInfo": {
        "name": "test-client",
        "version": "1.0"
      }
    },
    "id": 1
  }'

# Call a tool
curl -X POST https://mcp-echo-stateless.yourdomain.com/mcp \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Mcp-Session-Id: YOUR_SESSION_ID" \
  -d '{
    "jsonrpc": "2.0",
    "method": "tools/call",
    "params": {
      "name": "echo",
      "arguments": {
        "message": "Hello from MCP!"
      }
    },
    "id": 2
  }'

Architecture

Stateless Design

• No session persistence between requests
• Request context exists only for the duration of each request
• No Redis or database dependencies
• Thread-safe using Python's contextvars for request isolation

Integration with OAuth Gateway

The service is designed to work as part of the MCP OAuth Gateway architecture:

1. Traefik routes requests based on domain/path
2. ForwardAuth middleware validates OAuth tokens
3. Authenticated requests are forwarded with user context headers
4. Service processes requests and returns responses

Health Monitoring

The service includes a comprehensive health check that:

• Validates MCP protocol implementation
• Checks system resources (CPU, memory)
• Verifies service responsiveness
• Uses actual protocol initialization for validation

Development

Running Locally

# Start the service
just up mcp-echo-stateless

# View logs
just logs mcp-echo-stateless

# Run tests
just test mcp-echo-stateless

Debugging

Enable debug mode for verbose logging:

MCP_ECHO_DEBUG=true just up mcp-echo-stateless

Important Notes

• Not for Production Authentication: This service decodes tokens without verification for debugging purposes only
• Stateless Operation: No data persists between requests
• Diagnostic Focus: Designed for debugging and testing, not production workloads
• CORS Handling: CORS headers are managed by Traefik, not the service itself

Related Services

• mcp-echo-streamablehttp-server-stateful: Stateful variant with session persistence
• auth: OAuth authentication service that provides token validation
• traefik: Reverse proxy handling routing and authentication middleware