MCP Center

MCP Center is a local MCP gateway with a built-in Web UI. It manages multiple child MCP servers, keeps their configuration in one place, and exposes a single Streamable HTTP MCP endpoint for your client to connect to.

It can aggregate:

• tools
• resources
• resource templates
• prompts

To avoid collisions, every exposed capability is prefixed with the child server name:

• tool: exa_web_search_exa
• resource: filesystem_file:///tmp/a.txt
• prompt: docs_summarize

Usage Model

Run MCP Center directly with npx, then connect your MCP client to the HTTP endpoint it starts:

1. Start mcp-center with npx @sunwu51/mcp-center
2. Open the Web UI to add or edit child MCP servers
3. Point your MCP client at http://localhost:3000/mcp

Quick Start

1. Start MCP Center

npx @sunwu51/mcp-center

This command executes the package's CLI entry directly. No global install is required.

By default it uses ~/.mcp-center/mcp.json. If the file does not exist, it will be created automatically as:

{
  "servers": []
}

You can also pass a custom config path:

npx @sunwu51/mcp-center --config /path/to/mcp.json

Or:

npx @sunwu51/mcp-center /path/to/mcp.json

2. Open the Web UI

Open:

http://localhost:3000/ui

From the UI you can:

• add HTTP or stdio child MCP servers
• edit server config
• enable or disable a server
• delete a server
• probe a server before saving to inspect tools/resources/templates/prompts
• selectively enable only part of a server's capabilities
• view connection status and loaded capabilities

3. Connect your MCP client to MCP Center

Use this endpoint:

http://localhost:3000/mcp

Your MCP client must support Streamable HTTP transport.

How It Works

MCP Center acts as a proxy in front of multiple child servers:

• child servers can be HTTP MCP servers or local stdio MCP servers
• MCP Center connects to them as a client
• it lists their capabilities and republishes them through one HTTP endpoint
• calls and reads are forwarded to the original child server

Capability filtering is applied per child server:

• enabledTools
• enabledResources
• enabledResourceTemplates
• enabledPrompts

If a filtering field is omitted or empty, MCP Center exposes all items of that type from that child server.

Configuration File

The config file format is:

{
  "servers": [
    {
      "name": "exa",
      "url": "https://mcp.exa.ai/mcp",
      "httpHeaders": {
        "Authorization": "Bearer YOUR_TOKEN"
      },
      "enabledTools": ["web_search_exa"]
    },
    {
      "name": "filesystem",
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "/path/to/workspace"
      ],
      "env": {
        "NODE_ENV": "production"
      },
      "enabledTools": ["read_file", "write_file"],
      "enabledResources": ["file:///path/to/workspace/README.md"],
      "enabledPrompts": ["summarize_file"]
    }
  ]
}

Server Fields

Common fields:

• name: required, must be unique
• enabled: optional, set false to keep the server in config but not connect to it
• enabledTools: optional string array
• enabledResources: optional string array
• enabledResourceTemplates: optional string array
• enabledPrompts: optional string array

HTTP child server fields:

• url: required for HTTP transport
• httpHeaders: optional request headers

STDIO child server fields:

• command: required for stdio transport
• args: optional argument array
• env: optional environment variables

Client Configuration

The exact client config depends on the client, but the target should be the MCP Center HTTP endpoint:

{
  "mcpServers": {
    "mcp-center": {
      "url": "http://localhost:3000/mcp"
    }
  }
}

If your client expects a transport field, use its Streamable HTTP mode and point it to the same URL.

If you want to launch MCP Center from another tool or script, use the same npx entry:

{
  "command": "npx",
  "args": [
    "-y",
    "@sunwu51/mcp-center"
  ]
}

HTTP API

The Web UI uses these routes:

• GET /api/servers: list configured servers
• POST /api/servers: add a server
• PUT /api/servers/:index: update a server
• DELETE /api/servers/:index: delete a server
• PATCH /api/servers/:index/toggle: enable or disable a server
• GET /api/servers/status: get current connection status
• GET /api/servers/:name/capabilities: get loaded capabilities for a connected server
• POST /api/probe: temporarily connect to a server config and inspect capabilities before saving

Runtime Behavior

• Default port is 3000
• Set PORT to change it
• The config file is watched for changes
• When the config changes, MCP Center reloads child servers automatically
• Child servers are loaded in parallel
• Failed child servers do not stop the main HTTP service from starting

Example:

PORT=8080 npx @sunwu51/mcp-center

PowerShell:

$env:PORT=8080
npx @sunwu51/mcp-center

Development

Install dependencies:

npm install

Run locally:

npm start

Run tests:

npm test

License

MIT