mcp-apps-builder

name

mcp-apps-builder

description

**MANDATORY for ALL MCP server work** - mcp-use framework best practices and patterns. **READ THIS FIRST** before any MCP server work, including: - Creating new MCP servers - Modifying existing MCP servers (adding/updating tools, resources, prompts, widgets) - Debugging MCP server issues or errors - Reviewing MCP server code for quality, security, or performance - Answering questions about MCP development or mcp-use patterns - Making ANY changes to server.tool(), server.resource(), server.prompt(), or widgets This skill contains critical architecture decisions, security patterns, and common pitfalls. Always consult the relevant reference files BEFORE implementing MCP features.

IMPORTANT: How to Use This Skill

This file provides a NAVIGATION GUIDE ONLY. Before implementing any MCP server features, you MUST:

1. Read this overview to understand which reference files are relevant
2. ALWAYS read the specific reference file(s) for the features you're implementing
3. Apply the detailed patterns from those files to your implementation

Do NOT rely solely on the quick reference examples in this file - they are minimal examples only. The reference files contain critical best practices, security considerations, and advanced patterns.

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MCP Server Best Practices

Comprehensive guide for building production-ready MCP servers with tools, resources, prompts, and widgets using mcp-use.

⚠️ FIRST: New Project or Existing Project?

Before doing anything else, determine whether you are inside an existing mcp-use project.

Detection: Check the workspace for a package.json that lists "mcp-use" as a dependency, OR any .ts file that imports from "mcp-use/server".

├─ mcp-use project FOUND → Do NOT scaffold. You are already in a project.
│  └─ Skip to "Quick Navigation" below to add features.
│
├─ NO mcp-use project (empty dir, unrelated project, or greenfield)
│  └─ Scaffold first with npx create-mcp-use-app, then add features.
│     See "Scaffolding a New Project" below.
│
└─ Inside an UNRELATED project (e.g. Next.js app) and user wants an MCP server
   └─ Ask the user where to create it, then scaffold in that directory.
      Do NOT scaffold inside an existing unrelated project root.