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

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
164,398 StarsApache-2.0

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
164,398 StarsApache-2.0

Source Driven Development

addyosmani/agent-skills

Coding

Grounds every implementation decision in official documentation. Use when you want authoritative, source-cited code free from outdated patterns. Use when building with any framework or library where correctness matters.

typescriptpython
80,654 StarsMIT

Context Engineering

addyosmani/agent-skills

Coding

Optimizes agent context setup. Use when starting a new session, when agent output quality degrades, when switching between tasks, or when you need to configure rules files and context for a project.

CodexClaude Code
typescriptreact
80,654 StarsMIT

Git Workflow And Versioning

addyosmani/agent-skills

Coding

Structures git workflow practices. Use when making any code change. Use when committing, branching, resolving conflicts, or when you need to organize work across multiple parallel streams. Use when cutting a release, choosing a semantic version bump, tagging, or writing a changelog.

securityreview
80,654 StarsMIT

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
80,654 StarsMIT