MCP Server Builder

Build production-ready MCP servers with tools, resources, prompts, and interactive widgets using mcp-use.

Before You Code

Decompose user requests into tools, widgets, and resources. Decide what needs UI vs text.

Read design-and-architecture.md: when planning what to build, deciding tool vs widget, or designing UX flows.

Implementation

• Tools, resources, prompts → tools-and-resources.md: when writing server-side

  server.tool()

  ,

  server.resource()

  ,

  server.prompt()

  code
• Visual widgets (React TSX) → widgets.md: when creating interactive UI widgets in

  resources/

  folder
• Response helper API → response-helpers.md: when choosing how to format tool/resource return values
• URI template patterns → resource-templates.md: when defining parameterized resources
• Server proxying & composition → proxy.md: when composing multiple MCP servers into a unified aggregator

Quick Reference

import { MCPServer, text, object, markdown, html, image, widget, error } from "mcp-use/server";
import { z } from "zod";

const server = new MCPServer({ name: "my-server", version: "1.0.0" });

// Tool
server.tool(
  { name: "my-tool", description: "...", schema: z.object({ param: z.string().describe("...") }) },
  async ({ param }) => text("result")
);

// Resource
server.resource(
  { uri: "config://settings", name: "Settings", mimeType: "application/json" },
  async () => object({ key: "value" })
);

// Prompt
server.prompt(
  { name: "my-prompt", description: "...", schema: z.object({ topic: z.string() }) },
  async ({ topic }) => text(`Write about ${topic}`)
);

server.listen();

Response helpers:

text()

,

object()

,

markdown()

,

html()

,

image()

,

audio()

,

binary()

,

error()

,

mix()

,

widget()

Server methods:

• server.tool()

  - Define executable tool

• server.resource()

  - Define static/dynamic resource

• server.resourceTemplate()

  - Define parameterized resource

• server.prompt()

  - Define prompt template

• server.proxy()

  - Compose/Proxy multiple MCP servers

• server.uiResource()

  - Define widget resource

• server.listen()

  - Start server