OpenCairn
Open-source AI knowledge OS for notes, docs, and agents
OpenCairn launched on June 1, 2026 with 5 votes, #2,466 of 22,647 launches that month and more than 75% of that year's launches. The site was not reachable when checked in September 2026.
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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