A networked outliner versus an AI-native note store
Roam Research is a tool for thought built around a graph. Daily notes, block-level references, wiki links, and queries let power users connect ideas at a fine grain. If you like thinking in linked blocks and assembling a personal graph, Roam is a deep, well-loved option.
Hjarni is built around a different goal: giving your AI a memory. It is a knowledge base of plain Markdown notes that assistants read and write through an official MCP server. The aim is durable, AI-readable context, not block-level graph mechanics.
Official versus community MCP
This is the distinction worth being precise about. Roam has no official, vendor-built MCP server. There are good community and open-source servers that connect to Roam's official backend graph API with a token, and they can read and write: creating and editing pages and blocks, and searching. But they are community-maintained, and you set them up and trust them yourself.
Hjarni's MCP server is part of the product. It is official, built in, and uses OAuth, so connecting Claude or ChatGPT does not depend on third-party tooling. If you want the integration supported by the vendor rather than the community, that is the difference.
If you want block references and a graph to think in, Roam is excellent. If you want an official MCP and plain Markdown, Hjarni is the simpler path.
A concrete workflow difference
In Roam, you might keep a running graph: daily notes that link back to project pages, block references that surface a thought wherever it is relevant, and queries that pull related blocks together. It rewards careful, ongoing linking.
In Hjarni, you keep notes in folders and connect an assistant. Ask Claude to find recurring themes across a folder, draft a summary, and write it back as a new note. The structure is simpler; the payoff is that any AI you connect works from the same shared notes.
When Roam is the better fit
If you want a heavy-duty networked outliner with block references, a daily-notes workflow, and graph queries for personal thinking, Roam is a strong choice. It is built for exactly that kind of deep, linked note-taking.
When teams pick Hjarni instead
The case for Hjarni is an official, hosted MCP without community setup, plain Markdown you own, and a free tier to start. Roam has no permanent free plan, so Hjarni is also the lower-friction way to begin if you mainly want notes any AI can read and update.
Hjarni notes are plain Markdown, exportable as a ZIP anytime, hosted in the EU.