MCP Builder

Guide for creating high-quality MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. Use when building MCP servers to integrate external APIs or services, whether in Python (FastMCP) or Node/TypeScript (MCP SDK).

Overview

The MCP Server Development Guide provides a structured framework for building high-quality Model Context Protocol (MCP) servers. Found within the anthropics/skills repository, this resource assists developers in creating tools that allow Large Language Models to interact securely and efficiently with external services. The guide covers implementation strategies for both the Python-based FastMCP framework and the Node/TypeScript MCP SDK. By following these standards, developers can ensure their servers provide reliable data access and functional toolsets for agents like Claude and Codex. The repository, which has gained significant traction with over 150,000 stars, emphasizes best practices in design, testing, and security to facilitate robust integration between AI models and third-party APIs or local data sources.

Use Cases

Developing custom Python-based FastMCP servers to connect LLMs to internal data APIs.
Implementing TypeScript MCP SDK servers to provide AI agents with real-time research capabilities.
Standardizing tool design and security reviews for external service integrations in coding agents.

Install Notes

# Review source first
open https://github.com/anthropics/skills/blob/main/skills/mcp-builder/SKILL.md

Copy or clone the skill folder into your agent skills directory after reviewing its instructions and scripts.

Security Notes

Developers should prioritize secure tool design and data handling when building MCP servers. The guide emphasizes the importance of security reviews and testing to ensure that external API integrations do not expose sensitive information or allow unauthorized access during LLM interactions.

Related Skills

Claude API

anthropics/skills

Coding

Reference for the Claude API / Anthropic SDK — model ids, pricing, params, streaming, tool use, MCP, agents, caching, token counting, model migration. TRIGGER — read BEFORE opening the target file; don't skip because it "looks like a one-liner" — whenever: the prompt names Claude/Anthropic in any form (Claude, Anthr...

Claude CodeClaude
typescriptpython
172,724 StarsApache-2.0

Skill Creator

anthropics/skills

Coding

Create new skills, modify and improve existing skills, and measure skill performance. Use when users want to create a skill from scratch, edit, or optimize an existing skill, run evals to test a skill, benchmark skill performance with variance analysis, or optimize a skill's description for better triggering accuracy.

Claude CodeClaude
pythondesign
172,724 StarsApache-2.0

Shipping And Launch

addyosmani/agent-skills

Coding

Prepares production launches. Use when preparing to deploy to production. Use when you need a pre-launch checklist, when setting up monitoring, when planning a staged rollout, or when you need a rollback strategy.

typescriptjavascript
91,023 StarsMIT

Code Simplification

addyosmani/agent-skills

Coding

Simplifies code for clarity. Use when refactoring code for clarity without changing behavior. Use when code works but is harder to read, maintain, or extend than it should be. Use when reviewing code that has accumulated unnecessary complexity.

Claude CodeClaude
typescriptjavascript
91,023 StarsMIT

Using Agent Skills

addyosmani/agent-skills

Coding

Discovers and invokes agent skills. Use when starting a session or when you need to discover which skill applies to the current task. This is the meta-skill that governs how all other skills are discovered and invoked.

frontendsecurity
91,023 StarsMIT

Performance Optimization

addyosmani/agent-skills

Coding

Optimizes application performance across frontend, backend, queries, and databases. Use when performance requirements exist, when you suspect performance regressions, when Core Web Vitals or load times need improvement, when N+1 query patterns need fixing, or when profiling reveals bottlenecks.

typescriptjavascript
91,023 StarsMIT