# Ars Umbris

> Local-first IDE and framework for building typed, agentic knowledge graphs

Ars Umbris is an open-source, local-first workspace and framework for structuring personal or company knowledge in plain files. It adds YAML-based typing and diagnostics to Markdown documents, providing an interactive graph and MCP-compatible harness for AI agents to navigate and update your notes.

Website: https://arsumbris.ai/

## What it is for

- Build a structured company or personal knowledge base that AI agents can navigate
- Define custom schemas and validation rules for Markdown notes
- Connect coding agents like Claude Code to a typed local note graph via MCP
- Inspect relationships, broken links, and metadata diagnostics across linked files

## Features

- au-engine: Live typed graph that indexes files, resolves references, and catches structural errors
- au-host: Malleable IDE interface with customizable projections, graph views, and editors
- au-mcp: Agent meta-harness offering typed tools, profiles, and Claude Code adapters
- YAML-based note schemas supporting validation constraints and custom fields
- Interactive graph visualization with note previews and backlink tracking
- Local-first architecture that runs entirely on plain local files

## Pricing

Open source. Free and open source on GitHub

## Details

- Type: Web app
- Category: [Productivity](https://xiry.app/topics/productivity.md)
- Topic: [Knowledge Management](https://xiry.app/topics/productivity/knowledge-management.md)
- Open source: yes
- Platforms: macOS, Linux, Windows, Self-hosted
- For: Developers, researchers, and technical knowledge workers structuring documentation for AI agents
- Alternative to: Obsidian, Logseq, Anytype
- Tags: knowledge graph, pkm, agents, mcp, markdown, local first

## Why it was saved

- [@arscontexta, 25 February 2026](https://x.com/arscontexta/status/2026492755430474002): A real product embodying the article's thesis: browse a note graph, hover nodes for note previews, search notes and chat with an agent about them ('Ask about your notes…').

## Compare

- [Alternatives to Obsidian](https://xiry.app/alternatives/obsidian.md)

## Related

- [Notion](https://xiry.app/resources/notion): Connected workspace for notes, docs, databases, and AI automation. (Web app, Freemium)
- [Andrej Karpathy's LLM Knowledge Base Workflow](https://xiry.app/resources/andrej-karpathy-s-llm-knowledge-base-workflow): A workflow for using LLMs to compile and maintain personal wikis (Framework, Free)
- [Are.na](https://xiry.app/resources/are-na): Ad-free platform for saving, organizing, and connecting ideas into channels (Web app, Freemium)
- [LLM Living Knowledge Base Pipeline](https://xiry.app/resources/llm-living-knowledge-base-pipeline): Architecture framework for building an LLM-maintained markdown wiki that compounds knowledge (Framework, Free)
- [llm-wiki](https://xiry.app/resources/llm-wiki): A design pattern for building LLM-maintained personal knowledge bases in markdown (GitHub repo, Free)
- [YapThread](https://xiry.app/resources/yapthread): Turn Twitter bookmarks into a searchable AI knowledge base with citations (Web app)

Updated 10 October 2026. Page: https://xiry.app/resources/ars-umbris

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