"Creating a Graph on Vector Knowledge Base Using CozoDB" matching MCP connectors:

For queries a model can't confidently place: resolves or declines. Built to decline, not guess.

A semantic search server that gives AI assistants instant access to Dodo Payments documentation and knowledge base.

AI-first file sharing and collaboration. 251 tools give agents a full workspace: file storage, branded shares, comments, workflows, and built-in RAG. 50GB free, no credit card.

**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

NVIDIA AI knowledge graphs — 20 domains. 4x F1, 11x fewer tokens, SHA-256 provenance. MCP-native.

Serve a folder of Markdown notes as an MCP server: hybrid search, reading, and sourced answers.

NVIDIA NemoClaw knowledge graph — 55 nodes, F1 0.576 (+269% vs RAG), 11x fewer tokens. MCP-native.

Build and run grounded business agents over MCP: agents, knowledge bases, skills, Storylines.

Disposable private vector search + semantic RAG for AI agents. x402 pay-per-call, no account.

Collaborative, cache-first web search for agents — cited answers from a shared live-web pool.

Your company's brain for AI agents. Cited, permission-aware knowledge across every system.

Historical market memory for AI agents using semantic vector search across years of financial market data. Discover similar market regimes, price patterns, and market context for quantitative research and algorithmic trading.

Diffbot MCP — Knowledge Graph company enrichment + web content extraction (diffbot.com)

A multi-domain reference corpus where every answer drills down to its cited, verified source.

Kannada/English Carnatic flute KSGMS syllabus — search lessons, log practice, ask a RAG guru.

Multilingual YouTube → Knowledge Pack engine. Paste a video URL and get a structured pack — summary, key ideas, glossary, quiz, transcript with timestamps — in Spanish, Portuguese, German, or English. Anonymous endpoint plus OAuth-gated tools for library search, RAG Q&A on a single pack, and Anki export.

Marketplace where AI agents buy and sell books — curated domain knowledge that improves tasks.

Semantic search over a 200-chunk ACLM lifestyle medicine knowledge base.

Syracuse is an MCP server that gives agents reliable company and industry/region news. Every result is a structured event that is typed, dated, and linked to its source article. It's built for precision over volume, so an agent can act on it directly without a human in the loop weeding out wrong-entity matches or hallucinated stories. It's free for individuals, and in an open, anonymised benchmark against Exa, Tavily, Linkup and Perplexity it currently leads on company news.

The world's first named AI prompt quality score. Score, optimize, and compare LLM prompts before they hit any model. Free tier available. Built on PEEM, RAGAS, G-Eval, and MT-Bench frameworks. x402-native on Base.