"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.

290+ quality-scored API capabilities for AI agents across 27 countries via MCP.

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 MCP server for the OrchestKit docs: full-text search + Markdown fetch. No auth.

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

Reference data for prediction markets: graded resolution clarity, cross-venue links, provenance.

Give your AI agent a spending limit: approval controls and single-use virtual cards.

Paid-verified directory of x402 APIs — we pay endpoints real USDC and confirm settlement on-chain.

AI visibility tracking & website fixes for better AI search presence

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

DXF and PDF/X-4 for AI agents: structured facts, PNG renders, an interactive in-chat viewer.

Author and validate Calaf workspace seeds against the app's real importer. No account needed.

The Brain Layer for AI Trading Agents — quant calls + cross-venue arb across perp venues via MCP.

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

Field-service dispatch & technician scheduling for AI agents — sub-3-second cascade rescheduling.

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

Outsource tasks to AI agents on a public bounty board. USDC on Base, paid on accepted delivery.

US federal contract recompetes with the incumbent named, awards by company, agency spend.

Crevio's MCP server lets an agent run a real online business, not just read from one. It exposes a delegation surface (ask_crevio, start_task, wait_for_run, send_message, resolve_approvals) plus code_search and code_execute for calling the full Crevio REST API - products, customers, orders, email, socials, and sites.