"How to Query a Knowledge Graph Using an Ontology" matching MCP servers:

Reference implementation of the Operational Ontology pattern: MCP tools are generated from a typed business domain model (objects, links, actions) — one tool per query shape and per action, deliberately no raw SQL tool. Writes pass business-rule preconditions, are audited, and write back to the systems of record; refusals are machine-readable. Ships with a demo orders ontology spanning two legacy

Enables building and querying vector-based knowledge graphs with node and edge management and semantic search.

RAG Knowledge Graph - MCP server providing AI-powered tools and automation by MEOK AI Labs

Graph-based tool retrieval for LLM agents. Builds a tool graph from OpenAPI/MCP specs and retrieves multi-step workflows via hybrid search (BM25 + graph traversal + embedding), recovering accuracy from 12% to 82% with 79% fewer tokens. Also works as an MCP Proxy to aggregate multiple servers behind 3 meta-tools.

Provides a unified MCP interface over Uniswap V2, V3, and V4 across multiple chains via The Graph, enabling agents to query token prices, top pools, pairs, and recent swaps with clean JSON output.

A self-hosted, MIT-licensed MCP server that securely connects private documents and markdown files to LLMs. It provides a lightweight, local-first RAG infrastructure compatible with any MCP-enabled AI client or framework.

An MCP server that enables querying Polymarket prediction market data through The Graph subgraphs. It provides tools for accessing market stats, trader P\&L, user positions, and orderbook activity using AI agents.

An MCP-native evidence retrieval platform that ingests source material, builds lexical and vector indexes, performs hybrid retrieval, and returns structured evidence packages for AI assistants.

Enables agents to convert Markdown into WhatsApp-compatible formatting, including styled text, lists, and tables that fit a phone's monospace width.

Search 47,000+ marketing agencies and get AI-matched with fitted agencies, from Pick an Agency.

Provides agents with real Linux VMs to run commands, manage files, expose ports, and track costs, all through an ephemeral sandbox service.

Provides a read-only MCP interface to the Santismm Knowledge Platform, offering tools to retrieve curated content on engineering, AI patterns, architectures, governance, and agent taxonomy with structured output in English, Spanish, and Portuguese.

MCP server for querying AAVE V2/V3 lending protocol and governance data via The Graph subgraphs. Exposes 14 tools and 5 guided prompts that any AI agent (Claude, Cursor, Copilot, etc.) can use to query lending markets, user positions, health factors, liquidations, flash loans, rate history, and AAVE governance — across 7 chains (Ethereum, Base, Arbitrum, Polygon, Optimism, Avalanche, Fantom) via

RAG Knowledge - MCP server providing AI-powered tools and automation by MEOK AI Labs

A Model Context Protocol server for querying PyPI package information, dependencies, and compatibility checking. Supports advanced dependency analysis, download statistics, and trending analysis.

A runtime-free MCP server that converts source code into AST🌲, regardless of language.

MCP server for managing an OKF markdown knowledge base, enabling AI agents to query, read, write, and auto-sync architectural decisions and rules via Git.

Cross-chain cryptocurrency swaps via Chainflip. Get quotes, execute swaps, and track progress. No API key required to get started.

Search Vascue's public healthcare-operations documentation: AI front desk for clinics, provider-side insurance claims automation, Cliniko integration, security. Public content only.

Text-to-speech MCP server that enables AI assistants to read text aloud on the user's computer using Windows SAPI, with no API key or cloud service required.