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

Enables AI agents to query organizational architecture and governance constraints, returning evidence-grounded answers from documented structures.

MCP server for querying versioned C2PA specification knowledge graphs, enabling AI agents to browse entity definitions, validation rules, and version diffs via natural language.

Enables searching Google's Knowledge Graph for real-world entities via two tools: search by query or lookup by Machine ID, returning structured data including entity types, descriptions, and URLs.

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

Enables searching and querying Korean law ontology via SPARQL, with tools for law search, detail, agency, region, statistics, and network visualization.

An AI recipe recommendation server based on the MCP protocol, providing functions such as recipe query, classification filtering, intelligent dietary planning, and daily menu recommendation.

Enables AI assistants to query the Ubergraph biomedical ontology SPARQL endpoint with tools for custom SPARQL queries, term lookup, search, and hierarchy traversal.

An MCP server for Dart AI task management that enables bulk operations using DartQL selectors to minimize token usage and context rot. It provides tools for batch updates, task and document CRUD, and safe CSV imports with integrated dry-run capabilities.

Token-efficient Figma MCP server with image export, query DSL, and design token support.

Enables querying and comparing products from MM's retail (B2C) and wholesale (B2B) platforms in Vietnam, including price comparisons, stock availability checks, and multi-store support with Vietnamese language integration.

Enables full CRUD control of Ontology items in Microsoft Fabric, including entity types, relationships, data bindings, and workspace discovery through natural language.

Enables AI assistants to search arXiv papers, retrieve metadata, browse categories, and read paper text.

Enables querying GoldSrc game servers (e.g., Half-Life, Counter-Strike 1.6) for server info, player lists, rules, and RCON commands.

MCP server for running read-only SQL queries across MySQL and PostgreSQL databases with safety guardrails, credentials stored outside source, and support for multiple databases.

Enables querying official Brazilian Central Bank PTAX dollar closing exchange rates by specific date, date range, or most recent available quotation.

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.

Enables MCP clients like Claude to query Chinese A-share market data, including K-line charts with forward/backward adjustment, limit-up and limit-down pools, per-stock fund flows, index quotes, and stock news, with automatic symbol normalization and retry handling for throttled data sources.

Provides A-share (Chinese stock market) quantitative analysis through tools for stock screening, northbound capital flow tracking, dragon-tiger list analysis, margin trading, sector analysis, technical indicators, IPO info, and limit-up/down statistics using akshare data.

Enables a model to call the Microsoft Graph API directly through nine verb-shaped tools with per-user on-behalf-of authentication, so users can read, create, update, delete, search, batch, upload, download, and resolve attachments without server-side business logic or allow-lists.