mcp

mcp is a Model Context Protocol module for V.

It provides:

• typed JSON-RPC request, notification, response, and initialize payload helpers
• a synchronous Client that performs the MCP initialize handshake automatically
• a server-side Server with tool, resource, resource template, and prompt registration
• streamable HTTP and stdio transports behind a common transport interface
• queues for server notifications and server-initiated requests
• buffered while waiting for a response

HTTP example

import mcp

fn main() {
    mut client := mcp.connect('http://localhost:8000/mcp')!
    init := client.initialize()!
    println(init.server_info.name)
    client.close()
}

Stdio example

import mcp

fn main() {
    mut client := mcp.connect_stdio('my-mcp-server', ['--stdio'], mcp.ClientConfig{})!
    client.notify('notifications/cancelled', {
        'requestId': 1
    })!
    client.close()
}

Server example

import mcp

fn main() {
    mut server := mcp.new_server(
        name:    'my-v-mcp-server'
        version: '1.0.0'
    )

    server.add_tool(mcp.Tool{
        name:        'say_hello'
        description: 'Greets a user by name'
    }, fn (_ mcp.Context, _ string) !mcp.ToolResult {
        return mcp.tool_text_result('Hello, user!')
    })!

    server.serve_stdio()!
}

Notes

• Client.request auto-initializes when needed.
• Client.take_notifications and Client.take_requests drain queued server messages.
• The HTTP transport supports JSON responses and text/event-stream POST responses.
• Server.serve_http uses a single MCP endpoint, returns JSON by default, and will return SSE for POST requests that accept only text/event-stream.