
OpenCairn
Open-source AI knowledge OS for notes, docs, and agents
What it does
OpenCairn is an open-source AI knowledge OS that turns notes, documents, and web sources into a connected workspace for search, answers, writing, and agent workflows. Unlike a simple note app or chatbot, it is built for source-grounded knowledge work: ingest files, ask questions with context, trace answers back to sources, generate artifacts, and run workflows across your workspace. It is self-hostable, multi-LLM friendly, and designed for control over your data and tools.
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Hi HN, Nick here. We’re launching OpenKnowledge (https://openknowledge.ai/), a “what you see is what you get” markdown editor that has direct integrations with Claude, Codex, and other agents. Available as MacOS app or Web UI+CLI. Fully free/local and OSS. We built this because we wanted a Notion-like experience for writing and sharing markdown files across our team. Obsidian is the best alternative we tried, but found it doesn’t have a true WYSWIG UI and it didn’t integrate well with Claude/Codex outside of community plugins. So we built OpenKnowledge. It takes…
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