@zmdb/mcp

@zmdb/mcp provides transport-neutral MCP client and server cores. It validates every protocol envelope, routes only registered tools, resolves caller identity through an application-supplied function, and bounds remote call count and response bytes.

The package does not open sockets, read process streams, mount an HTTP framework, or depend on an MCP SDK. Applications own stdio or HTTP framing and authentication.

Install

yarn add @zmdb/[email protected] @zmdb/[email protected]

Prerelease (1.0.0-beta.2). Requires Node.js 26+ and is ESM-only. The runtime uses platform APIs and caller-supplied transports.

Server

import { defineTools } from '@zmdb/ai/chat';
import { createMcpServer } from '@zmdb/mcp';

const tools = defineTools({
  lookup: {
    spec: {
      name: 'lookup',
      parameters: { type: 'object', properties: {}, required: [] },
    },
    validate: value => value,
    handler: (input, identity) => JSON.stringify({ input, identity }),
    effectful: false,
  },
});

const server = createMcpServer(tools, {
  serverInfo: { name: 'catalog', version: '1.0.0' },
  identify: transport => authenticateTransport(transport),
});

const answer = await server.handle(message, transport);

identify is mandatory. The application decides how a stdio process or HTTP request becomes an authenticated identity before a tool runs.

Client

import { createMcpClient } from '@zmdb/mcp';

const client = createMcpClient(sendJsonRpc, {
  maxCalls: 32,
  maxResponseBytes: 256 * 1024,
});

const tools = await client.listTools();
const result = await client.callTool('lookup', { id: 'item-7' });

sendJsonRpc supplies the transport. Remote schemas, arguments, and result text remain untrusted data; validate application payloads at your own boundary.

Entry point

• @zmdb/mcp — MCP_PROTOCOL_VERSION, createMcpServer, createMcpClient, McpProtocolError, and their public contracts.

Documentation

Full project documentation is at https://ambasta.github.io/zmdb/.

License

GNU General Public License v3.0 or later (GPL-3.0-or-later).