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

A Model Context Protocol (MCP) server that enables MCP clients like Claude Desktop to interact with protocols.io, a popular platform for sharing scientific protocols and methods.

A Firecrawl MCP server with built-in support for multiple API key rotation, enabling web search, scraping, crawling, extraction, and more via MCP clients.

Enables querying normalized real-world asset data through MCP tools, including listing assets, retrieving asset details, comparing yields against SOFR, and checking eligibility by jurisdiction.

An MCP server that lets AI clients search and retrieve Doctor of Credit articles, categories, and deals via flexible tools, interpreting article content at request time.

Enables AI agents to search and retrieve historical Spanish Call of Duty gaming community posts, with free search previews and pay-per-page citation-ready access via x402.

Per-unit cost of 13 back-office tasks done by a person vs by software, in the US, Greece and Ukraine, with an official statistic behind every hourly wage. Bundled data, works offline.

Every other colour API tells you what goes together. Colour Memory tells you what it means, where the evidence ends, and what it must not claim. 47,515 hand-researched records, graded A–E, every result cited. 91 specialist tools built for agents that need precision, not guesses. Direct MCP: https://api.colourmemory.com/mcp — no signup, no key for the free tools (10 calls).

Free remote MCP for Core Web Vitals metrics by CMS, CDN, and framework (Chrome field data + multi-site crawl). No auth. Endpoint: https://www.corewebvitals.io/api/state-of-cwv/mcp

Gives Claude direct access to the Africa API for comprehensive data on all 54 African nations, including economic indicators, markets, trade, government, elections, and policies.

Enables access to live precious metals prices, historical data, market intelligence, and portfolio management with AI/LLM integration.

A scientific reasoning framework that leverages graph structures and the Model Context Protocol (MCP) to process complex scientific queries through an Advanced Scientific Reasoning Graph-of-Thoughts (ASR-GoT) approach.

Enables Claude Desktop and Claude Code to query Korean KIPRIS Plus and European EPO OPS patent data for bibliographic details, family members, legal status, claims, descriptions, abstracts, and search results using each user's own free API keys.

Provides a read-only API over a book catalogue, offering tools to search books, retrieve book details and series, and inspect provenance and source agreement data.

Bilingual (EN/ES) AI-writing detection that shows the evidence instead of a percentage: named tells with line and column, hidden-character inspection, and citation cross-checking against a document's own bibliography. Seven of its nine tools run entirely locally and never touch the network.

Gateway connector between LLM agents and world data, providing access to financial market prices, macroeconomic indicators, and news through a bundled endpoint catalog.

Provides AI agents with Korean national fiscal data (budgets, settlements, and fiscal programs) from multiple government APIs through 7 tools, enabling natural language queries.

MCP server for the Infobel GetData API, enabling AI agents to search businesses, retrieve records, and browse categories and locations.

Enables agents to verify whether citations exist and match canonical records, and whether URLs resolve and contain expected content, with evidence-backed confirmed, contradicted, or unknown verdicts.

Provides read-only access to the Handigraphs Stats API v1, enabling discovery of sports resources and querying of protected sports statistics.

MCP server that extracts structured JSON from public URLs for AI agents using schemas like product, article, and company.