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

Turn Obsidian notes into agent-ready context, preview-only plans, and safe repo handoffs.

Enables AI agents to navigate, search, and rank notes in an Obsidian vault using graph relationships, providing context-aware access to knowledge without exposing raw file contents.

Provides a self-tending knowledge base for AI agents, automatically harvesting session transcripts into facts and state notes, and injecting relevant context into new sessions via MCP hooks.

Enables agents to search, read, list, and amend a git-backed markdown knowledge base, automatically committing and publishing changes.

Enables complex queries over data on the DANDI Archive and provides a system for managing text notes. It features tools for note creation, resources for note access via custom URIs, and prompts for generating summaries.

Searches Reddit for answers to questions and saves Q&A sessions to Notion.

Enables semantic search of the KJV Bible and personal knowledge graph for scripture study, notes, prayers, and memory verses, all running locally with no cloud dependencies.

Enables AI agents to search, read, create, and maintain a local-first knowledge base using hybrid retrieval and Markdown note management through the Model Context Protocol.

Enables saving URLs, local files, plain text, and platform content (WeChat, X, YouTube, PDF, images, audio/video, Telegram) as structured Markdown knowledge cards in an Obsidian vault, with optional AI-powered classification and tagging.

Enables filtered, read-only querying of a Notion audit trail and action queue as four native tools (filtered lists and single-row lookups), with enum parameters validated against the live database schema and errors that report allowed values. It never writes to Notion, returns flat JSON rows, and keeps the integration token server-side.

A FastMCP server that suggests wikilinks for Obsidian notes based on a pre-computed knowledge graph, helping surface connections while writing.

MCP server that converts PDF, video, web, and audio inputs into structured Markdown notes with support for checkpointing, batch processing, and Obsidian integration.

A Cloudflare Workers-based MCP server for Notion knowledge base management, enabling intelligent search, automatic recording of code snippets, and statistics analysis through natural language.

Enables read-only querying of an Obsidian knowledge base through MCP tools and resources, including full-text search, node and link retrieval, related-note traversal, and pathfinding between concepts.

Enables AI agents to explore and analyze a markdown vault as a traversable knowledge graph, with tools for searching, traversing, and finding implicit semantic connections between notes.

Enables saving and searching local notes, with tools to list notes and search backup files.

Provides coding agents with a shared, Markdown-based engineering knowledge base to search, capture, create, and update internal conventions, API details, infrastructure configs, and development setup via lightweight MCP tools.

Read-only MCP server that surfaces contradictions in an Obsidian vault's knowledge graph via semantic search and reasoning edges.

A personal knowledge base MCP server that allows AI assistants to manage notes, tasks, and ideas through tools, resources, and prompts.

Scans markdown vaults to identify concepts mentioned but not defined, ranks gaps by priority, and generates research questions or random long-tail topics to fill knowledge gaps.