@galdor/mcp

A Model Context Protocol (MCP) client and server for galdor — JSON-RPC 2.0 over stdio, SSE, and Streamable HTTP. Expose galdor tools to any MCP client, or consume a remote MCP server's tools as a galdor Registry.

Protocol version 2024-11-05. The server runs in strict mode with panic recovery and bounded concurrency; the client multiplexes requests by id with a per-call timeout. Includes an anti-DNS-rebinding origin guard, plus an in-memory transport and an SSE client transport for tests.

Install

bun add @galdor/mcp   # or: npm install @galdor/mcp

Serve tools over stdio

import { z } from "zod";
import { defineTool, Registry } from "@galdor/core/tool";
import { Server, StdioTransport } from "@galdor/mcp";

const echo = defineTool({
  name: "echo",
  description: "Echo the given text back.",
  input: z.object({ text: z.string() }),
  handler: ({ text }) => ({ text }),
});

const server = new Server(new Registry(echo), { name: "my-mcp", version: "1.0.0" });
await server.serve(new StdioTransport(process.stdin, process.stdout));

Serve over Streamable HTTP instead with serveHttp(port, handler).

Consume a remote MCP server

import { Client, StreamableHTTPClientTransport } from "@galdor/mcp";

const client = new Client(StreamableHTTPClientTransport.create("http://localhost:8000/mcp"), {
  info: { name: "my-client", version: "1.0.0" },
});
await client.initialize();

const tools = await client.listTools();
const result = await client.call("echo", { text: "hi" });
client.close();

StreamableHTTPClientTransport.create(url, { fetch }) accepts a custom fetch for auth, proxies, or retries.

License

Apache-2.0