Second brain app
A second brain that's private, portable, and AI-ready.
Granite turns scattered notes into a connected second brain: Markdown files with links, backlinks, tags, and a graph, synced to every device and encrypted at rest. Then let your AI assistant search it, so your second brain can answer back.
In short
A second brain is a personal knowledge system outside your head where you capture, connect, and resurface what you learn. Granite is a second brain app built on plain Markdown files with wikilinks and backlinks, version history, and offline sync, plus a built-in MCP server that turns it into an AI second brain your assistant can search with citations.
Capture · Connect · Recall
Everything a second brain needs, nothing it doesn't.
Wikilinks, backlinks, and a graph
Type [[ to link any note. Every note shows what links to it, and the graph shows how your ideas connect, so nothing you learn gets lost in a folder.
Plain Markdown
Obsidian-compatible .md files with frontmatter, embeds, tags, and callouts.
Every device, every version
Changes sync in seconds. Restore any earlier version of any note.
No signal, no problem
Keep writing offline; edits merge when you reconnect, and real conflicts keep both copies.
Find it in a keystroke
Search words, phrases, and tags across every vault. ⌘ P opens every command.
Ask your notes anything
Connect Claude, ChatGPT, or Cursor through MCP. Your assistant searches your vaults and answers with links to the exact notes, instead of making things up.
Encrypted, and never training data
Each vault has its own 256-bit encryption key. Your notes are never used to train AI models, and you can export everything as plain files at any time.
How to build a second brain in Granite
Four habits. One system.
Capture
Drop ideas, meeting notes, highlights, and links into an Inbox note from any device, even offline.
Connect
Link each note to the projects, people, and topics it touches with
[[wikilinks]]and#tags.Distill
Turn raw notes into evergreen notes in your own words. Backlinks show where each idea is used.
Ask
Let your AI assistant search your vaults to draft, summarize, and recall, with citations back to your notes.
Reading notes: The Mom Test
Ask about the past, not the future. Links to [[Customer interviews]] and [[Discovery playbook]].
Second brain apps compared
Why people move their second brain to Granite.
| What matters | Granite | Typical cloud note app | Local-only Markdown app |
|---|---|---|---|
| Your notes are plain Markdown files | Yes | Proprietary blocks | Yes |
| Sync with version history included | Yes, free plan included | Yes | Paid add-on or DIY |
| Live co-editing | Yes | Yes | No |
| AI tools can search your notes (MCP) | Built in, with permissions | Vendor's own AI | Community plugins |
| Notes never used to train AI | Never | Check the terms | Local files |
| Grows into a company knowledge base | SSO, SCIM, audit log | Higher tiers | No |
See detailed comparisons: Granite vs Obsidian · Granite vs Notion
FAQ
Second brain questions.
What is the best app for building a second brain?
The best second brain app keeps your notes in an open format, links ideas together, syncs reliably, and lets you find anything fast. Granite does all four with plain Markdown files, wikilinks and backlinks, sync with version history, and full-text search, and adds secure AI search through MCP so your assistant can use your second brain too.
What is an AI second brain?
An AI second brain is a personal knowledge base that an AI assistant can read. Instead of the AI guessing, it searches your own notes and answers with references. In Granite, you connect Claude, ChatGPT, Cursor, or another MCP client, choose which vaults it may use, and decide whether it can only read or also write.
Is Granite compatible with Obsidian?
Yes. Granite uses Obsidian-compatible Markdown: wikilinks, embeds, tags, callouts, and YAML frontmatter. You can import an Obsidian vault as a zip and keep working, and export it back as plain files whenever you like.
Does Granite work with the PARA method or Zettelkasten?
Yes. Granite doesn't force a structure. Use folders for PARA (Projects, Areas, Resources, Archives), atomic linked notes for Zettelkasten, or both. Backlinks and the graph work across any structure.
Is my second brain private?
Your notes are encrypted at rest with a key per vault, sent over TLS, never used to train AI models, and never shown to an AI tool unless you connect one and allow it. You can export or delete everything at any time.
Is Granite free?
Yes. The Free plan includes one synced vault, 250 MB of storage, two devices, and seven days of history, with unlimited local notes. Pro is $4 a month for 10 vaults, unlimited devices, 12 months of history, and AI tool access.
Give your company a memory it can trust
Free for one person. Business is free for 14 days, no card required.
- Encrypted with a key per vault
- Never used to train AI
- Export as Markdown anytime