MCP Server Directory

Diagnose AI workflows for failure, security, and handoff risks — RED/AMBER/GREEN per node.

io.github.pdaxt/pqvault

Post-quantum secrets manager for AI agents. ML-KEM-768 + X25519 + AES-256-GCM.

io.github.0xthaner/reputa

Reputa: wallet risk & security plus DeFi cover (insurance) analyses, paid via x402.

Intent security pre-flight checks for autonomous AI agents.

Zero-knowledge proof validator and cryptographic locker.

Inaturalist

iNaturalist MCP — citizen-science species observations (free, no auth for read-only)

io.github.matetools/mcp-server

35 utility tools for AI agents — mate.tools API. Hash, regex, SEO, random, DNS, SSL, JWT.

Pubmed

PubMed MCP — wraps the NCBI E-utilities API (biomedical literature, free, no auth)

PII and secrets sanitization gateway with advanced OCR merging logic.

io.github.onetrueclaude-creator/hebbian-vault

Usage-adaptive Obsidian vault search: Hebbian + PageRank + BM25 hybrid ranking.

io.github.operantlabs/operant-mcp

Security testing MCP server for penetration testing, forensics, and vulnerability assessment

io.github.mbeato/apimesh

74 paid web-analysis APIs (SEO, security, TLS, DNS, email) as MCP tools. USDC via x402.

OpsConduit Jobber MCP

Customer-hosted read-only MCP server for Jobber ops reports, OAuth setup, and GraphQL validation.

caruon

Carbon MCP — UK Carbon Intensity API (free, no auth)

catfacts

Cat Facts MCP — wraps Cat Facts API (free, no auth)

chucknorris

Chuck Norris MCP — wraps chucknorris.io (free, no auth)

holidays

Holidays MCP — wraps Nager.Date API (free, no auth)

cityuikes

Citybikes MCP — wraps CityBik.es API (free, no auth required)

guif

GBIF MCP — wraps the Global Biodiversity Information Facility API v1 (free, no auth)

ipinfo

IPInfo MCP — wraps ipinfo.io (free tier, no auth required for basic usage)

jokes

Jokes MCP — wraps JokeAPI v2 (free, no auth)

Agent Einstein — Autonomous Crypto Intelligence

40 AI crypto tools: whale tracking, security scans, DeFi analytics, quantum security, and more.

nationalize

Nationalize MCP — nationality prediction from first name (nationalize.io, free, no auth)

Nih Reporter

NIH RePORTER MCP — every NIH-funded research project (free, no auth)