GalaxyBrain brings variables and live references to local-first knowledge pages
GalaxyBrain is a local-first knowledge system where document pages support custom variables, formulas, and live cross-page references, all stored as structured JSON files with a built-in HTTP API and MCP tool.
Score breakdown
Developers and AI practitioners can point agentic coding tools like Claude Code or Codex directly at a GalaxyBrain folder via its MCP tool, enabling agents to read, write, and build on top of a reactive local knowledge base without any cloud dependency.
- 01Pages support custom variables, formulas, and live cross-page references that update in real time.
- 02All data is stored locally as structured JSON files — no account or server required.
- 03The entire app is a single HTML file that runs in the browser.
GalaxyBrain, posted to Hacker News by author j0ncc, is a local-first knowledge system that blurs the line between documents and structured data. Each page in the system can carry custom variables and formulas, turning ordinary notes into reactive, interconnected data sources. References between pages are live — updating a variable on one page propagates changes across everything connected to it in real time.
The entire application is delivered as a single HTML file that runs in the browser, requiring no account or server setup.
The entire application is delivered as a single HTML file that runs in the browser, requiring no account or server setup. All data persists locally as structured JSON files, keeping the user in full control of their information. A built-in HTTP API and an MCP tool expose the same capabilities available in the UI programmatically, allowing AI coding agents — the post specifically names Claude Code, Codex, or a local model — to be pointed at the same folder to read from and build on top of the knowledge base. The post describes the system as "deceptively complex under the hood" while acknowledging some rough edges, and invites community feedback on the approach.
Key facts
- 01Pages support custom variables, formulas, and live cross-page references that update in real time.
- 02All data is stored locally as structured JSON files — no account or server required.
- 03The entire app is a single HTML file that runs in the browser.
- 04A built-in HTTP API and MCP tool expose full app functionality programmatically.
- 05Compatible with AI coding agents such as Claude Code, Codex, or local models pointed at the same folder.
- 06Posted to Hacker News by author j0ncc.
Topics
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