"Examples of MCPs (Microservices Communication Protocols) That Do Not Require API Keys" matching MCP connectors:

Federated search of books and papers, BibTeX/RIS citations, open-access retrieval and reading.

Neutral, verification-gated MCP directory of Japan construction contractors (KIRA-audited).

Savvly MCP: query fund data, model projections, and compare against alternative retirement products.

Read-only breach intel, full history 2007-today: reports THAT an org was breached, never the data.

Search and cite US law from official sources, then form an LLC or nonprofit with free agent tools.

Polish law: search statutes (ISAP), court rulings, verify citations. Free tier + paid plans + x402.

Uptime monitoring: create and manage HTTP, API, SSL, ping, port and domain checks

Autonomous Model Context Protocol interface for querying on-premise NVIDIA DGX private AI hardware specs, modeling CapEx token ROI, executing M2M procurement, and onboarding into the Aradia Partner Program.

Neutral freight reference + validation layer for AI agents: ADR, HS, UN/LOCODE, freight math

Free, open MCP server for The Urantia Papers. 197 papers, 14,500+ paragraphs, 4,400+ entities.

Free: turn your AI chats into spaced-repetition vocabulary. 13 tools, reads and writes.

Money, FX and capital-market evidence with source clocks, canonical citations and explicit limits.

Riddle.com is a no-code platform for quizzes, surveys, personality tests, prediction games, interactive graphics, and leaderboards. Use the MCP to create, edit and analyze content.

Daily editorials, exit costs, depth concentration, tiers, and sealed records. No commodity futures.

Read any page or file as clean text, plus live news, weather, market holidays and timezone lookups for agents. Pay-per-call in USDC on Base via x402 — no signup, no API keys.

Russian company lookup (EGRUL/INN), Cyrillic search, RU page to Markdown. Pay per call in USDC.

Verify anything: email, phone, domain, URL and IBAN validation, phishing/malware URL screening, and OFAC sanctions checks. Pay-per-check in USDC on Base via x402 — no signup, no API keys.

EVM gas prices, Chainlink price feeds, token-safety screening, DEX swap quotes, ENS resolution, OFAC address screening and NFT data. Pay-per-call in USDC on Base via x402 — no signup, no API keys.

SEC filings, insider trades (Form 4), 13F institutional holdings, IPO calendar, macro indicators and FX rates. Pay-per-call in USDC on Base via x402 — no signup, no API keys.

Bank and lender monitoring with historical-evidence limits and eligibility flags beside every claim.