"Search functionality without API key requirement" matching MCP connectors:

Open scientific and engineering knowledge for AI agents: search, evidence, document publishing.

Push Realm is an MCP server and AI agent knowledge network where agents search proven fixes, publish what worked, and turn dead ends into open problems other agents can close. Compare how agents and tools perform in different topic areas.

Zero-Ops deploy of a private AI coding workspace onto your own VPS — straight from your AI chat. Provide only your Ubuntu server credentials and Fractera automatically configures everything (Nginx, HTTPS, auth, database, services) in about 10 minutes: 5 AI coding engines, an autonomous Hermes orchestrator, and private graph memory (LightRAG). No terminal, no DevOps. IP-first and free; a custom domain with HTTPS is an optional later step.

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

**ColdState Knowledge Search MCP Server** https://github.com/daniel-coldstate/coldstate-mcp Semantic search over 64.6M knowledge entries — the structured alternative to web search APIs and web scraping for LLM agents. No crawling, no rate limits, sub-3s responses. Cloud-hosted at services.coldstate.ai

Give your agent web search and authoritative datasets: S&P Global, FRED, OECD, SimilarWeb & more.

FastMCP server for TheBrain API — AI access to a personal knowledge graph, Tollbooth-monetized

Trend, stats & insight search across PSFK expert graphs with citable sources.

Free game-theory negotiation advisor for agents, plus paid receipted sessions and agent memory.

blicht.com knowledge platform: full-text search + Markdown articles (e-commerce, AI, lifestyle)

AI session memory: the brief your AI reads before every session so no session starts cold.

Memoket — access your recording transcripts, summaries, and key takeaways over MCP.

Mitosis agent-memory platform: pricing, docs search, platform status, agent skills. No auth.

Art provenance intelligence — 282K-node knowledge graph with cited answers and honest gaps.

Search and fetch Wikidata entities, execute SPARQL queries, and resolve external identifiers.

Query Shunki Ogino's public profile: his thesis, the tools he builds, and his writing.

People + life-in-days knowledge for AI agents. Public MCP; x402 on Base; OAuth for private tools.

Remote MCP server for The Colony — a social network for AI agents (posts, DMs, search, marketplace).

Shared, peer-validated knowledge archive for AI agents — search, contribute, and validate via MCP

Agentforce Vibes knowledge graph over MCP — quota chains, Pro/Core/Flex billing tiers, 43 nodes sourced to Salesforce docs. Works in claude.ai in 30 seconds.