Two takes on the same good idea
Vist and Hjarni start from the same conviction: your AI should read and write notes you actually own, not a black box buried inside one chat product. Both are hosted, both store plain Markdown you can export, both are hosted in the EU, and both ship a built-in MCP server so Claude, ChatGPT, and other assistants connect over OAuth with no plugins. If that shared idea is what drew you to either one, you will be happy with the connection experience on both.
The difference is the shape of the product around the notes. Vist is a notes-and-tasks app for one person. Hjarni is a knowledge base built to grow, and to be shared.
Where Vist shines
Vist is fast and keyboard-first. A single command palette opens every action, checkboxes become tasks with due dates parsed from plain language, and a Today view assembles itself. If your main job is to capture your own work and to-dos and have your assistant read them, that focus is a real strength, and Hjarni does not try to be a task manager.
Where Hjarni goes further
Hjarni invests in the knowledge base itself. Wiki-links connect notes into a graph your AI can traverse, so it gathers context from related notes instead of one folder at a time. Folder-level AI instructions tell each assistant how to write in each part of your system. Shared team spaces, a full REST API, Zapier, and file attachments turn it from a personal memory into something a whole team and its assistants work from.
If you expect your knowledge base to grow past your own desk, those are the features that keep it useful.
A concrete difference
Say two teammates are both working on the same launch. In Vist, each person keeps their own notes and tasks, and each assistant reads that one person's memory. In Hjarni, the launch notes live in a shared folder with its own AI instructions, so every teammate's ChatGPT or Claude reads and updates the same source of truth, and nobody re-explains the plan to their own AI.
Use Vist when you want a personal notes-and-tasks app your AI can read. Use Hjarni when you want a shared knowledge base your whole team's AI can read and maintain.
When Vist is the better fit
If you mostly want a single, snappy place for your own notes and tasks, you live in the keyboard, and you do not need wiki-links, per-folder AI rules, or team sharing, Vist is a clean choice. It does the personal-memory job well and stays out of your way.
When teams pick Hjarni instead
The case for Hjarni is not "Vist can't connect AI." It clearly can. The case is that some people and most teams want the knowledge to outlive a single person: linked notes, folder-level behavior, shared spaces, and an API to wire it into the rest of their stack. That is the part Hjarni is built around.