One vault, or everything the company knows
A vault holds what you put in it. Brain reads the tools the team already works in, with each source's permissions carried over, so the answer draws on all of it without anyone re-filing anything.
vs
Brain vs Obsidian
A private second brain on one machine, and the shared, governed, agent-queryable brain for a whole company.
Obsidian is a local-first markdown app and a genuinely loved one: your own second brain, in files you own, on your own machine, with backlinks and a plugin for almost everything. Brain is the shared company brain Obsidian was never built to be, with permission-aware retrieval for many people and AI agents, a content-blind tamper-evident record of every read, and an MCP endpoint agents query. It does not replace your vault. It governs what a team and its agents can see, and proves it.
Why teams compare them
The same question, two answers
Once notes are shared, who is asking starts to matter. Brain answers per person, and can withhold one sensitive part rather than refusing the whole document.
Where Obsidian is the better fit
For a private, local-first place to think, in plain files you fully own, with a vast plugin ecosystem, Obsidian is excellent and Brain is not trying to take its place.
The questions people actually ask about Obsidian
My vault already works. What would a team need that it doesn't have?
Nothing, while the vault is yours. A single-machine second brain is a fine thing and Brain is not a better notes app.
What changes is the unit. The moment several people and several agents read the same knowledge, the question stops being how it is filed and becomes who is allowed to see which part of it. That is a different product, not a bigger vault.
We could just sync the vault to a shared folder.
You can, and plenty of teams do. A synced folder shares the files.
What it does not do is say who opened which of them, or stop the wrong person opening one at all. Brain keeps an append-only record of every read: who asked, what was reached, what was withheld. Content-blind, so it proves the access without keeping the material.
Our agents can already read the vault through a plugin.
They can, and for one person's notes that is often enough.
A plugin reads whatever the vault holds, because on one machine there is nothing to check against. Brain gives agents an MCP endpoint governed exactly like a person: scoped to what that agent is cleared for, with limits, a human in the loop where it matters, and a kill switch. The answers come back with their sources attached.
And the notes that shouldn't be shared at all?
Those are usually not whole documents. They are a column, a clause, a name.
Blocking the file to protect one line costs the team the other ninety. Brain withholds the part and serves the rest, and marks plainly that something was held back, so nobody is left wondering whether the answer was complete.
At a glance
| Attribute | Brain | Obsidian |
|---|---|---|
| Who it is for | Many people and AI agents sharing one governed brain | One person's knowledge, on their own machine |
| Where it lives | Hosted, with per-tenant database isolation | Local Markdown files you own on disk |
| Access control | YesPermission-aware per person and per agent, plus field-level redaction | NoNot a multi-user concept; a vault is shared by syncing or publishing it, or through another file-sync service |
| Agent access | YesAn MCP endpoint, governed like a person, with limits, human-in-the-loop and a kill switch | PartlyAI comes from community plugins running against your local vault |
| Audit and proof | YesContent-blind, tamper-evident record of every read, with an optional on-chain anchor | NoNot applicable; the notes are local files |
| Sources | Slack, GitHub, Drive, Box, Confluence, Salesforce, Telegram, with permissions intact | Markdown files, plus a large community plugin ecosystem |
| How you start | Free to start, transparent self-serve tiers | Download the app; free for personal use |
Compared against publicly available information, last checked 20 September 2026. Products change. Tell us if something here is out of date: hello@heybrain.io
Who each one is for
Choose Brain if
- Teams and AI agents that need one shared, governed source of truth
- Permission-aware answers with field-level redaction across company knowledge
- A content-blind record of every read, optionally anchored on-chain
- Giving AI agents company knowledge over MCP, governed like people
Choose Obsidian if
- A private, local-first second brain on your own machine
- Anyone who wants full ownership of plain Markdown files
- Solo thinking and writing, with a deep plugin ecosystem
Nobody is moving their notes into another tool.
Nobody has to. Brain does not ask for your vault and does not want to be your editor.
It connects the shared tools the team already works in and reads them in place. Your own vault stays exactly where it is, on your own machine, yours.
Join the waitlistQuestions, answered
- Is Brain a replacement for Obsidian?
- No. Obsidian is a private, local-first Markdown brain for one person and Brain does not replace it. Brain is the shared, governed company brain that many people and AI agents query, with permissions and a verifiable record of every read.
- Can my AI agents query company knowledge the way they can't in a vault?
- Yes. Brain exposes an MCP endpoint, so agents read company knowledge under the same rules as people, with limits, human-in-the-loop and a kill switch. In Obsidian, AI comes from community plugins running against your local files.
- What does Brain give a team that a vault can't?
- Permission-aware retrieval, field-level redaction, a content-blind record you can verify yourself, and connectors to Slack, GitHub, Drive and more with permissions intact.
Other comparisons
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