MCP StreamableHTTP Client

A bridge client that enables local MCP (Model Context Protocol) clients like Claude Desktop to connect to remote MCP servers that use StreamableHTTP transport and require OAuth authentication.

Overview

The mcp-streamablehttp-client acts as a protocol bridge, converting between:

• stdio (standard input/output) - used by local MCP clients
• StreamableHTTP - used by remote MCP servers with OAuth protection

This enables seamless integration of OAuth-protected MCP services with tools that only support stdio-based MCP servers.

Features

• OAuth 2.0 Authentication - Full support for dynamic client registration (RFC 7591) and management (RFC 7592)
• Automatic Token Management - Handles token refresh, storage, and expiration
• Protocol Bridging - Transparent conversion between stdio and StreamableHTTP
• Session Management - Maintains MCP sessions across protocol boundaries
• Smart Command Parsing - Flexible argument formats for easy tool usage
• Claude Desktop Integration - Direct configuration support

Installation

Using pixi (Recommended)

pixi add --pypi mcp-streamablehttp-client

Using pip

pip install mcp-streamablehttp-client

Docker Deployment

FROM python:3.11-slim

# Install the package
RUN pip install mcp-streamablehttp-client

# Set working directory
WORKDIR /app

# Copy .env file (if exists)
COPY .env* ./

# Run the client
CMD ["mcp-streamablehttp-client"]

Using Docker Compose

services:
  mcp-client:
    image: mcp-streamablehttp-client:latest
    build:
      context: ./mcp-streamablehttp-client
    environment:
      - MCP_SERVER_URL=${MCP_SERVER_URL}
    volumes:
      - ./.env:/app/.env:ro
    stdin_open: true
    tty: true

# Build and run with docker-compose
docker-compose up -d

Quick Start

1. Initial Setup

First, authenticate with your MCP server:

# Using just (recommended)
just auth

# Or directly
mcp-streamablehttp-client --token

This will guide you through the OAuth flow and save your credentials to .env.

2. Test Connection

Verify your authentication:

just test-auth

3. Use with Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "my-oauth-server": {
      "command": "mcp-streamablehttp-client",
      "env": {
        "MCP_SERVER_URL": "https://mcp-fetch.yourdomain.com"
      }
    }
  }
}

4. Execute Commands

Run MCP tool commands:

# List available tools
just list-tools

# Execute a tool
just exec "fetch https://example.com"
just exec "echo message='Hello World'"

Configuration

All configuration is done through environment variables in .env:

Variable	Description	Required
MCP_SERVER_URL	Target MCP server URL	Yes
MCP_CLIENT_ID	OAuth client ID	Auto-generated
MCP_CLIENT_SECRET	OAuth client secret	Auto-generated
MCP_CLIENT_ACCESS_TOKEN	Current access token	Auto-generated
MCP_CLIENT_REFRESH_TOKEN	Refresh token	Auto-generated
MCP_CLIENT_REGISTRATION_TOKEN	RFC 7592 management token	Auto-generated
MCP_CLIENT_REGISTRATION_URI	RFC 7592 management endpoint	Auto-generated

Usage

CLI Commands

Authentication Commands

# Setup or refresh OAuth tokens
mcp-streamablehttp-client --token

# Test authentication status
mcp-streamablehttp-client --test-auth

# Clear all credentials
mcp-streamablehttp-client --reset-auth

MCP Commands

# List available tools
mcp-streamablehttp-client --list-tools

# List available resources
mcp-streamablehttp-client --list-resources

# List available prompts
mcp-streamablehttp-client --list-prompts

# Execute a tool command
mcp-streamablehttp-client -c "tool_name arguments"

Client Management (RFC 7592)

# Get client registration info
mcp-streamablehttp-client --get-client-info

# Update client registration
mcp-streamablehttp-client --update-client "client_name=New Name,[email protected]"

# Delete client registration
mcp-streamablehttp-client --delete-client

Advanced Usage

# Send raw JSON-RPC request
mcp-streamablehttp-client --raw '{"jsonrpc": "2.0", "method": "tools/list", "id": 1}'

# Run as continuous proxy (for Claude Desktop)
mcp-streamablehttp-client

Command Argument Formats

The client supports multiple argument formats for flexibility:

# JSON format (for complex arguments)
mcp-streamablehttp-client -c 'tool {"key": "value", "nested": {"foo": "bar"}}'

# Key=value format
mcp-streamablehttp-client -c 'tool key1=value1 key2=value2'

# Smart detection (URLs, paths, etc.)
mcp-streamablehttp-client -c 'fetch https://example.com'
mcp-streamablehttp-client -c 'read_file /path/to/file.txt'

# Simple string arguments
mcp-streamablehttp-client -c 'echo "Hello World"'

Architecture

┌─────────────────────┐     stdio      ┌──────────────────────┐     HTTP + OAuth    ┌─────────────────┐
│   Claude Desktop    │ ←------------→ │ mcp-streamablehttp-  │ ←----------------→ │  Remote MCP     │
│  (or other stdio    │   JSON-RPC     │      client          │  StreamableHTTP    │    Server       │
│    MCP client)      │                │  (Protocol Bridge)   │                    │ (OAuth Protected)│
└─────────────────────┘                └──────────────────────┘                    └─────────────────┘

The client acts as a transparent bridge, handling:

• Protocol conversion (stdio ↔ HTTP)
• OAuth authentication (token injection)
• Session management (state preservation)
• Error translation (HTTP → JSON-RPC)

Security

• OAuth tokens are stored securely in .env file
• Automatic token refresh before expiration
• SSL/TLS verification enabled by default
• Supports PKCE for authorization code flow
• Client credentials never exposed in logs

Development

Running Tests

# Run all tests
just test

# Run specific test
just test-auth

Building

# Build Docker image
just build

# Rebuild with no cache
just rebuild

Troubleshooting

Common Issues

1. "No credentials found"

   • Run mcp-streamablehttp-client --token to authenticate

2. "Token expired"

   • The client should auto-refresh, but you can force it with --token

3. "OAuth server not found"

   • Check MCP_SERVER_URL is correct
   • Ensure the server supports OAuth discovery

4. "Permission denied"

   • Your OAuth user may not have access to the requested resource
   • Check with your administrator

Debug Mode

Set environment variable for verbose logging:

export MCP_DEBUG=1
mcp-streamablehttp-client --test-auth

Examples

See the examples/ directory for:

• claude_desktop_config.json - Claude Desktop configuration
• command_examples.sh - Common command patterns
• demo.py - Python integration example
• token_example.md - OAuth flow walkthrough

License

[License information here]

Contributing

[Contribution guidelines here]