Hjarni

About Hjarni

Hjarni is a hosted Markdown knowledge base that exists to give ChatGPT and Claude a long-term memory you own. The problem it targets is the one every heavy assistant user hits: you explain your codebase, your house, your research corpus or your company's history to the model, the conversation ends, and the next one starts from zero. Hjarni gives the model a place to write things down and read them back. It exposes the whole base over MCP and a REST API, so the assistant can search notes, fetch a specific one, and update it mid-conversation — the product's own examples show Claude noticing that a stored fact is stale, updating the note, and the next conversation already knowing. Underneath it is a plain notes app: folders, tags, search, file attachments, and AI instructions that can be set at the whole-brain level or per folder, which the model then inherits. The ownership guarantees are the selling point and are stated plainly — every AI edit is visible and undoable, notes export to Markdown at any time, data is hosted in the EU on Hetzner, encrypted in transit and at rest, and the vendor does not train on your notes. It is listed in both the ChatGPT Apps Directory and the Claude Connectors Directory.

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