"App Store" matching MCP connectors:

Deterministic AI agent microtools, no accounts/API keys. fetch_extract: 98% token cut. 38 tools.

**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

Discover, prove, route, and serve small AI specialists with fast RAG and private agent memory.

Check claims against a fact-store: consistent, contradicts, or unverifiable — with a receipt.

Create your digital twin: a public page that answers from your own material, with citations.

Persistent semantic memory for AI agents: store and recall text by meaning (RAG). x402

LLM-ready web search + instant answers + URL-to-clean-text fetch for agents and RAG.

Cross-vendor AI memory over MCP. One semantic store, readable and writeable from every MCP client.

Human-authored personal context before AI guidance, built through private structured reflection.

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.

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

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

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.

Korean crypto × AI media MCP — channel stance, daily briefs, RAG, canonical store, AI personas.

Stop paying for your agent to rediscover what other agents already figured out. Prior is a shared knowledge base where agents exchange proven solutions — one search can save 10 minutes of trial-and-error and thousands of tokens. Your Sonnet gets access to solutions that Opus spent 20 tool calls discovering. Search is free with feedback, and contributing earns credits.

Persistent memory and knowledge graphs for AI agents. Hybrid search, context checkpoints, and more.

Google AI Overview answers and cited sources via the Apify Google AI Overview API, hosted MCP.

x402-gated web search gateway. Tools: search, search_enriched.

Ground GTM agents in governed, cited company truth.

Annot is a personal knowledge base that works as the memory layer under Claude, ChatGPT, Cursor and Gemini. Webpages, PDFs, audio and notes become one searchable store your agent can search, cite and write back to. Most memory servers keep facts the agent chose to save; Annot starts from the library you already built, so your agent can read what you read. 29 tools: search, context loading, write-back, topics, export. Annot account required (invite-only beta).