TheBrain is a knowledge management application from TheBrain Technologies LP that connects ideas, notes, files, and web links. It runs on Windows, macOS, Linux, iOS, Android, and the web. The proprietary app is free for personal and commercial use. Optional subscriptions expand cloud services, AI usage, and collaboration.
One thought in several contexts
A brain contains named thoughts and their connections. Each thought can hold a note and attachments. Users create thoughts by dragging a relationship gate, then entering a name. Choosing an existing thought connects it instead of creating a duplicate.
- Parent links place broader categories above a thought.
- Child links group related material beneath it.
- Jump links connect related thoughts without a hierarchy.
A thought can have several parents, so the same item can appear in different contexts. Removing a link leaves the thought intact. One type supplies a thought’s classification and appearance, while multiple tags mark additional characteristics. Aliases let searches recognize alternative names.
The map follows the active thought
The Plex centers the active thought and arranges its connections around it. Activating another thought recenters the map. Outline and Mind Map layouts present the same relationships differently.
Tree View expands children, parents, and jumps as a hierarchy. Cards View groups thoughts by creation, modification, or access date. Its detail control changes how much note and attachment content each card shows.
Quick Thoughts and BrainBox
Quick Thoughts collects written notes in an account inbox. Users later turn an item into a child thought, append it to a note, or attach it as Markdown. BrainBox collects files, links, and web clippings for later placement. Both inboxes require a signed-in account.
Files and URLs can also attach directly to a thought. On desktop, users can copy files into the brain or link external files and folders. External links reference their existing location rather than copying the contents into cloud storage.
Notes that connect back to the graph
The editor supports formatted text and Markdown, with headings, tables, images, and checklists. Notes save automatically. Users can map a link in prose to a parent, child, or jump connection. Backlinks list notes that link here; unlinked mentions identify names or aliases that lack links.
Note Versions displays earlier text and highlights changes. Users copy passages back into the current note. This history belongs to the thought’s note, rather than attached Markdown files.
Search results and reusable reports
Typing part of a name finds thoughts immediately; further results search notes and supported attachment text. Quotes match phrases, while Boolean operators combine or exclude terms. Childward and selection filters restrict the search area.
Images have no text recognition. External files and attachments that Light Sync has not downloaded may appear by name only. Reports combine type, tag, date, and other conditions into a thought list. Users save a report to run it again.
Timeline and note tasks
Events carry dates, times, recurrence, and optional thought associations. The Timeline and Day Navigator show them chronologically, with reminders that users can snooze or dismiss.
The To-Do List gathers checkboxes from notes. Checking an item there also changes its original note. Filters narrow the list by type, tag, or dates. Opening this panel requires administrator rights on the brain.
Cerebro works inside the current brain
Users ask Cerebro questions or request graph changes in plain language. Its tools read notes, summarize supported attachments, create thoughts, and change connections. Permission settings determine which actions need approval. Undo All reverses the latest response’s changes. Users must undo newer manual edits before that control works again.
AI Scripts reuse instructions with parameters, conditions, and active-thought variables. Users run them from chat or toolbar buttons. Desktop clients can use an OpenAI-compatible local endpoint; AI still requires an account. Cerebro’s tools operate within the current brain. They cannot extract text from images or scanned PDFs without a text layer.
Local copies and shared access
Desktop and mobile clients support offline work, then reconcile changes through sync. Light Sync retrieves attachments on demand; full sync keeps them available locally. Automatic sync requires the app to run.
Users can publish a brain, share an unlisted link, or invite named readers. TeamBrain adds multi-user editing and access administration. A shared thought page exposes an individual thought through its own link. Creating one requires a synced brain and administrator access; private thoughts cannot become shared pages.
Pro Service expands private sync and AI allowances; Max increases the AI allowance further.
Moving material between tools
TheBrain imports Markdown folders, Obsidian vaults, Evernote exports, mind maps, and outlines into a new or existing brain. Export choices include Markdown, structured JSON, text outlines, and folder trees. Installed clients also export notes as PDF or HTML.
A brain archive preserves the graph for reimport, excluding external attachments. Users must download cloud attachments before creating a backup. Exporting a brain requires administrator access. The local API lets external scripts create connections and query brain data.
