GalaxyBrain is a local-first knowledge system where pages have variables, formulas, and live references between them. Define a value on one page, reference it from another, and it stays in sync automatically. Like a programming environment crossed with a document editor. Everything is stored as structured JSON files on your machine. There's a built-in HTTP API and MCP tool so you can point Claude Code, Codex, or a local model at the same folder and build on top of it. No account needed.
Hey PH! I soft launched GalaxyBrain here about a year ago. The response was encouraging but it became clear pretty quickly that the foundation wasn't strong enough for what we were trying to build.
So I convinced my smartest friend (@viralplatipuss) to join as technical cofounder and we rebuilt the entire product from the ground up. GalaxyBrain is closer to a spreadsheet engine than a note app, and that level of complexity needed a foundation built properly.
It's ready now. The core is solid. You can have thousands of pages with dynamic values, all connected to each other, all staying perfectly in sync and updating in real time.
It's been a multi-year labor of love. You might find some rough edges on the fringes but the engine underneath is rock solid.
Would love to hear what you think and if this approach has potential.
No comment highlights available yet. Please check back later!
About GalaxyBrain on Product Hunt
“An information operating system powered by local files”
GalaxyBrain launched on Product Hunt on April 20th, 2026 and earned 93 upvotes and 3 comments, placing #15 on the daily leaderboard. GalaxyBrain is a local-first knowledge system where pages have variables, formulas, and live references between them. Define a value on one page, reference it from another, and it stays in sync automatically. Like a programming environment crossed with a document editor. Everything is stored as structured JSON files on your machine. There's a built-in HTTP API and MCP tool so you can point Claude Code, Codex, or a local model at the same folder and build on top of it. No account needed.
GalaxyBrain was featured in Productivity (651.7k followers) on Product Hunt. Together, these topics include over 132.9k products, making this a competitive space to launch in.
Who hunted GalaxyBrain?
GalaxyBrain was hunted by Jon Wheatley. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
Want to see how GalaxyBrain stacked up against nearby launches in real time? Check out the live launch dashboard for upvote speed charts, proximity comparisons, and more analytics.
Jon Wheatley
Hey PH! I soft launched GalaxyBrain here about a year ago. The response was encouraging but it became clear pretty quickly that the foundation wasn't strong enough for what we were trying to build.
So I convinced my smartest friend (@viralplatipuss) to join as technical cofounder and we rebuilt the entire product from the ground up. GalaxyBrain is closer to a spreadsheet engine than a note app, and that level of complexity needed a foundation built properly.
It's ready now. The core is solid. You can have thousands of pages with dynamic values, all connected to each other, all staying perfectly in sync and updating in real time.
It's been a multi-year labor of love. You might find some rough edges on the fringes but the engine underneath is rock solid.
Would love to hear what you think and if this approach has potential.