MCP Hub

MCP Hub acts as a central coordinator for MCP servers and clients, providing two key interfaces:

1. Management Interface (/api/*): Manage multiple MCP servers through a unified REST API and web UI
2. MCP Server Interface (/mcp): Connect ANY MCP client to access ALL server capabilities through a single endpoint

This dual-interface approach means you can manage servers through the Hub's UI while MCP clients (Claude Desktop, Cline, etc.) only need to connect to one endpoint (localhost:37373/mcp) to access all capabilities. Implements MCP 2025-03-26 specification.

Feature Support

| Category | Feature | Support | Notes |
|----------|---------|---------|-------|
| Transport ||||
| | streamable-http | ✅ | Primary transport protocol for remote servers |
| | SSE | ✅ | Fallback transport for remote servers |
| | STDIO | ✅ | For running local servers |
| Authentication ||||
| | OAuth 2.0 | ✅ | With PKCE flow |
| | Headers | ✅ | For API keys/tokens |
| Capabilities ||||
| | Tools | ✅ | List tools |
| | 🔔 Tool List Changed | ✅ | Real-time updates |
| | Resources | ✅ | Full support |
| | 🔔 Resource List Changed | ✅ | Real-time updates |
| | Resource Templates | ✅ | URI templates |
| | Prompts | ✅ | Full support |
| | 🔔 Prompts List Changed | ✅ | Real-time updates |
| | Roots | ❌ | Not supported |
| | Sampling | ❌ | Not supported |
| | Completion | ❌ | Not supported |
| Marketplace ||||
| | Server Discovery | ✅ | Browse available servers |
| | Installation | ✅ | Auto configuration |
| Real-time ||||
| | Status Updates | ✅ | Server & connection state |
| | Capability Updates | ✅ | Automatic refresh |
| | Event Streaming to clients | ✅ | SSE-based |
| | Auto Reconnection | ✅ | With backoff |
| Development ||||
| | Hot Reload | ✅ | Auto restart a MCP server on file changes with dev mode |
| Configuration ||||
| | ${} Syntax | ✅ | Environment variables and command execution across all fields |
| | VS Code Compatibility | ✅ | Support for servers key, ${env:}, ${input:}, predefined variables |
| | JSON5 Support | ✅ | Comments and trailing commas in configuration files |

Simplified Client Configuration

Configure all MCP clients with just one endpoint:

{

    "mcpServers" : {

        "Hub": {

            "url" : "http://localhost:37373/mcp"  

        }

    }

}

The Hub automatically:
- Namespaces capabilities to prevent conflicts (e.g., filesystem__search vs database__search)
- Routes requests to the appropriate server
- Updates capabilities in real-time when servers are added/removed
- Handles authentication and connection management

Key Features

- Unified MCP Server Endpoint (/mcp):
- Single endpoint for ALL MCP clients to connect to
- Access capabilities from all managed servers through one connection
- Automatic namespacing prevents conflicts between servers
- Real-time capability updates when servers change
- Simplified client configuration - just one endpoint instead of many

- Dynamic Server Management:
- Start, stop, enable/disable servers on demand
- Real-time configuration updates with automatic server reconnection
- Support for local (STDIO) and remote (streamable-http/SSE) MCP servers
- Health monitoring and automatic recovery
- OAuth authentication with PKCE flow
- Header-based token authentication

- Unified REST API:
- Execute tools from any connected server
- Access resources and resource templates
- Real-time status updates via Server-Sent Events (SSE)
- Full CRUD operations for server management

- Real-time Events & Monitoring:
- Live server status and capability updates
- Client connection tracking
- Tool and resource list change notifications
- Structured JSON logging with file output

- Client Connection Management:
- Simple SSE-based client connections via /api/events
- Automatic connection cleanup on disconnect
- Optional auto-shutdown when no clients connected
- Real-time connection state monitoring

- Process Lifecycle Management:
- Graceful startup and shutdown handling
- Proper cleanup of server connections
- Error recovery and reconnection

- Workspace Management:
- Track active MCP Hub instances across different working directories
- Global workspace cache in XDG-compliant state directory
- Real-time workspace updates via SSE events
- API endpoints to list and monitor active workspaces

Components

Hub Server

The main management server that: - Maintains connections to multiple MCP servers - Provides unified API access to server capabilities - Handles server lifecycle and health monitoring - Manages SSE client connections and events - Processes configuration updates and server reconnection

MCP Servers

Connected services that: - Provide tools, resources, templates, and prompts - Support two connectivity modes: - Script-based STDIO servers for local operations - Remote servers (streamable-http/SSE) with OAuth support - Implement real-time capability updates - Support automatic status recovery - Maintain consistent interface across transport types

Installation

npm install -g mcp-hub

Basic Usage

Start the hub server:

```bash
mcp-hub --port 3000 --config path/to/config.json