MCP Dynamic Proxy

A dynamic MCP (Model Context Protocol) proxy server that provides progressive discovery and lazy loading of MCP servers, reducing initial context size from 20-300 tools to just 3 core tools.

How it works

Assistant (Cursor) -MCP-> MCP Dynamic Proxy -MCP-> MCP Servers (AWS, PostgreSQL, etc.)

The proxy exposes only 3 core tools that let you discover and interact with any number of configured MCP servers without loading them all upfront.

Tools

mcp_list_servers

List all configured MCP servers with their metadata (id, description, tags, principal tools).

Parameters: None

Returns: {count: int, servers: [...]}

mcp_list_tools

List all tools from a specific MCP server with their JSON schemas. Automatically loads the server if needed.

Parameters:

• server_id (required): The MCP server ID (e.g., "aws-knowledge-mcp-server")

Returns: {server_id: str, status: "loaded" | "error", tool_count: int, tools: [...], error?: str}

mcp_execute_tool

Execute a tool from a specific MCP server. Automatically loads the server if needed.

Parameters:

• server_id (required): The MCP server ID
• tool_name (required): The tool name (e.g., "aws___read_documentation")
• arguments (required): Dictionary matching the tool's JSON schema

Returns: {server_id: str, tool_name: str, status: "success" | "error", result?: any, error?: str}

Configuration

config/mcp.json

Create a config/mcp.json file with your MCP server configurations:

{
  "version": "1.0",
  "mcpServers": {
    "aws-knowledge-mcp-server": {
      "description": "AWS knowledge base with documentation, best practices, and service information",
      "tags": ["aws", "documentation", "cloud", "knowledge"],
      "tools": ["aws___read_documentation", "aws___search_documentation"],
      "command": "uvx",
      "args": ["fastmcp", "run", "https://knowledge-mcp.global.api.aws"]
    },
    "microsoft.docs.mcp": {
      "description": "Microsoft Learn documentation and Azure documentation access",
      "tags": ["microsoft", "azure", "documentation", "learn"],
      "tools": ["microsoft_docs_search", "microsoft_code_sample_search", "microsoft_docs_fetch"],
      "command": "uvx",
      "args": ["fastmcp", "run", "https://learn.microsoft.com/api/mcp"]
    }
  }
}

Configuration fields:

• description: Human-readable description
• tags: List of tags for organization
• tools: Optional list of principal tool names (not exhaustive)
• command: Command to start the MCP server
• args: Arguments for the command
• env: Optional environment variables (supports ${VAR_NAME} expansion)

Cursor Configuration

Add to your Cursor MCP configuration:

{
  "mcpServers": {
    "mcp-dynamic-proxy": {
      "command": "uvx",
      "args": ["mcp-dynamic-proxy"],
      "env": {
        "MCP_CONFIG_PATH": "/path/to/config/mcp.json"
      }
    }
  }
}

License

MIT