GalaxyBrain.com
GalaxyBrain · Leaning · Business
GalaxyBrain.com is a local-first workspace that writes like a document and calculates like a spreadsheet. It keeps your pages as plain files on your own computer, open to any AI agent you connect.
About GalaxyBrain.com
What Is GalaxyBrain
GalaxyBrain is an information operating system built on local files, and it doubles as a local files workspace you can inspect with any text editor. It sits in the space between a note app, a wiki, a spreadsheet, and a task manager. Instead of scattering your work across four separate tools, it puts computation and structure directly inside the page, so a document and spreadsheet live side by side.
The whole workspace is just one folder on your computer. Pages live as plain .jsonl files, images go into an images/ folder, and a small workspace.jsonl records which tabs are open. There's no account and no cloud account to sign into. You pick a folder, and that folder becomes your workspace.
The catch is the platform. GalaxyBrain runs in Chrome and Edge on desktop, and there's no mobile app yet. The team also labels the current release a beta (version 0.9.5), so some rough edges are expected. Pages are stored locally, which means backups are your responsibility, but you can zip the folder at any time.
Getting Started
- Open app.galaxybrain.com in Chrome or Edge on a desktop computer. First-time visitors land inside a live demo so you can try the editing before committing to anything.
- Pick an empty folder to use as your workspace, or let GalaxyBrain clone the demo into a folder you choose. Returning visits reopen your most recent folder automatically.
- Write pages using blocks. Start a line with
#for a heading,-for a bullet,[]for a checkbox, or1.for an ordered list, then press Space to convert it in place. - Type
/to insert a live value like a word count,@to link another page, and$inside templates to drop in placeholders such as$DateToday. - Point an MCP-aware AI tool at the folder and let it work with the same pages, or save an offline HTML build to run everything from
file://with no network.
Product Information
A quick look at GalaxyBrain.com's pricing, supported platforms, and performance.
Best for
The users, tasks, and scenarios where this tool fits best.
Users
- Researchers and writers who keep long-running notes and want structure without a database
- Small teams and solo builders who care about file ownership
Tasks
- Building a personal knowledge base that mixes writing and numbers
- Letting an AI agent edit your notes safely
Scenarios
- Tracking recurring entries like a journal or meeting log
- Working without a network
Key features
Local files as the workspace
Every page GalaxyBrain creates is a plain .jsonl file inside a folder you pick, with images saved to images/ and open tabs recorded in workspace.jsonl. That makes the workspace portable and easy to inspect. You can zip it, back it up, or pass the whole folder to someone else, and nothing depends on a remote account.
Blocks that mix prose and structure
A page body is built from blocks, and each block can freely combine headings, paragraphs, bullets, checkboxes, ordered lists, images, variables, and page links. You might keep a Summary block, a Todos block, and a Projects block on the same page. Structure isn't bolted on top of the writing, it's part of it.
Live variables and formulas
A variable is a named cell with a formula. Formulas handle arithmetic, constants, functions like sqrt and round, and references to other variables or meta values. Results recalculate whenever the data they depend on changes, and unresolved formulas show an inline error token like #NOT_FOUND or #CIRCULAR_REF so you can spot the problem without leaving the page.
Cross-page aggregation
Variables compose across pages. You can point the / menu at a block of page links, choose a variable name that exists on those pages, and pick Count, Sum, Average, Min, or Max. The total updates live as the linked pages change, which turns a set of connected pages into a lightweight roll-up without any separate reporting tool.
Templates with placeholders
Templates are blueprint pages with the full editing feature set plus three placeholders: $NextNumber, $NextDay, and $DateToday. Creating a page from a template clones the blueprint, resolves the placeholders, and drops a link back into the block you started from. The block remembers your last template, so repeated entries take one click.
AI agents over MCP
Point an MCP-aware tool like Claude Code, Claude Desktop, Cursor, or Codex at your workspace and it turns into an AI agent workspace where the tool can read, search, traverse, and edit pages. Agents run under the same validation the editor applies to your own typing, so they can't skip the rules. GalaxyBrain also writes CLAUDE.md and AGENTS.md files into the folder with the install snippet included.
Offline mode
From the workspace menu you can save an offline workspace as a single standalone HTML file that runs from file:// against a folder on your disk. Core editing works with no network at all. You can share that file with someone else, and each person runs an independent copy against their own folder.
Pros and cons
Pros
- Your data stays in plain files on your disk, so there's no lock-in and you can back up or share the folder however you like.
- The document and spreadsheet model live in the same page, which removes the usual copy-paste between a notes app and a sheet.
- AI agents connect through MCP and operate under the same validation rules as you, which lowers the risk of an agent quietly corrupting a page.
- Variables aggregate across linked pages, so roll-ups update on their own instead of needing a manual export.
Cons
- It runs in Chrome and Edge on desktop only, so there's no mobile app and no Safari or Firefox support, which limits use on the go.
- The current release is a 0.9.5 beta, so features and file formats may still shift between versions.
- Pages are stored locally, so if you lose the folder without a backup, there's no cloud copy to fall back on.
- Offline builds can't load the demo projects, and recent-folder history may not persist between sessions when running from `file://`.
Frequently asked questions
GalaxyBrain is a workspace for turning messy information into structured pages that write like a document and calculate like a spreadsheet. You use it to keep notes, tasks, and live numbers inside one local folder, and an AI agent can work with the same pages.
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