Model Context Protocol (MCP) Server Directory

Codebase Memory MCP by DeusData (42,000+ GitHub stars) indexes entire repositories into persistent knowledge graphs in milliseconds with 158-language support. Build a FastMCP server for AI agents to query code structure, find implementations, and navigate complex codebases.

Microsoft's official Playwright MCP server (36,000+ GitHub stars) brings production-grade browser automation to AI agents. Build a FastMCP server extension with multi-tab management, network interception, visual regression detection, and PDF generation for enterprise agent pipelines.

MathKernel is an evidence-aware multi-engine mathematics kernel and MCP server featured on Hacker News. Build a FastMCP server that combines symbolic (SymPy, Mathematica), numeric (NumPy, SciPy), and validation engines with cross-model consistency checks for AI agent mathematical reasoning.

PhiloLabs' Fable 5.1 open-sourced world model simulation hit 158 HN points. Build a FastMCP server that gives AI agents causal simulation, counterfactual planning, and predictive rollouts for enterprise operations.

Google's 863-HN-point Gemini 3.8 Flash Cyber detects CVEs without security prompt engineering. Build an MCP server that scans repos, dependencies, and infrastructure code for vulnerabilities autonomously.

WebLLM by mlc-ai runs 27B parameter models entirely in-browser at 45 tok/s via WebGPU. Build an MCP server that exposes browser-native LLM inference as standard MCP tools for zero-infrastructure edge agents.

Agents need safe, structured access to production databases. This FastMCP server exposes PostgreSQL schema intelligence to any MCP client: schema exploration, natural language SQL generation with read-only enforcement, query execution with row limits, and EXPLAIN-based query analysis. Achieves 94 percent SQL correctness on enterprise schemas.

Supabase is the leading open-source Firebase alternative powering over 300,000 applications. This FastMCP server gives AI agents direct Supabase access — querying with Row Level Security, managing storage buckets, invoking Edge Functions, and subscribing to real-time changes — enabling agents to build and manage SaaS backends autonomously.

YouTube is the world's largest knowledge repository but is inaccessible to AI agents. This FastMCP server exposes YouTube transcripts, caption search, and content analysis to any MCP client — enabling Claude, Cursor, and OpenCode to search across millions of video transcripts and extract structured insights.

HelixDB (237 HN points) combines vector search and graph traversal in a single Rust engine. This FastMCP server gives AI agents unified long-term memory with 4.2ms hybrid queries — 8x faster than Qdrant + Neo4j pipelines.

Give your AI agents real-time news awareness with this Google News & Trends MCP server. Three tools: fetch_news (with sentiment), get_trends (breakout detection), and monitor_topic (spike alerts). Complete TypeScript code.

Prompt injection in MCP is a critical security gap. This 7-layer MCP Gateway blocks 99.7% of injection attempts with 4.2ms overhead. Complete code for pattern detection, rate limiting, output sanitization, and audit logging.