OpenGravity

OpenGravity was born from frustration with Google Antigravity’s rate limits: the author, a heavy Antigravity user, liked the UI enough that instead of switching to a CLI or VS Code-based tool, they fed screenshots of Antigravity into Google AI Studio and used Gemini to help recreate the interface from scratch. The result is a pure HTML/CSS/JS browser app requiring zero installation, using the WebContainer API to run a live terminal (via xterm.js) directly in-browser.

It’s Bring Your Own Key (BYOK), meaning you supply your own model API key rather than being subject to a shared service’s rate limits, and it includes direct local file system sync plus a proactive autonomous agent capable of orchestrating basic software engineering tasks, running shell commands, and editing files in real time.

GPL-3.0 licensed, the project is explicitly labeled alpha and a work in progress by its own author — it handles basic coding tasks but isn’t presented as a finished, production-ready tool.

What You Get

• A browser-based, zero-install IDE UI modeled on Google Antigravity’s interface
• A live terminal running via the WebContainer API (xterm.js) directly in the browser
• Bring Your Own Key (BYOK) model access, avoiding a shared service’s rate limits
• An autonomous agent that can run shell commands and edit files as part of basic software engineering tasks

Common Use Cases

• Getting the Google Antigravity UI experience without hitting its rate limits, by supplying your own API key
• Running a lightweight, zero-install coding environment directly in a browser tab
• Experimenting with an autonomous coding agent that can execute shell commands and edit files in real time
• Trying an alpha-stage, actively evolving alternative to Antigravity for basic coding tasks

Under The Hood

Architecture OpenGravity is built in pure HTML/CSS/JS specifically to minimize footprint and avoid an installation step, using the WebContainer API to run a real terminal environment inside the browser (surfaced through xterm.js) rather than simulating one. Local file system sync connects that in-browser environment to your actual project files, and the autonomous agent layer orchestrates commands and edits against that synced file system.

Tech Stack Plain HTML, CSS, and JavaScript (no framework), WebContainer API for in-browser Node.js/terminal execution, and xterm.js for the terminal UI. BYOK model access means it calls whichever LLM provider you configure directly, rather than routing through a shared backend.

Code Quality As an explicitly alpha, work-in-progress project built rapidly (per the author’s own account, over a couple of days using AI-assisted UI recreation), it hasn’t yet accumulated the maturity signals of an established tool — GitHub activity shows infrequent recent maintenance despite decent initial traction.

What Makes It Unique Most “recreate a popular AI IDE” clones are throwaway demos; OpenGravity’s origin story — screenshots fed into Gemini to reconstruct a UI the author specifically wanted to keep using without rate limits — and its use of WebContainer for a genuinely functional in-browser terminal make it a more complete recreation than a purely cosmetic clone, even while still in alpha.

Self-Hosting

Licensing Model GPL-3.0 licensed — open source with no license key.

Self-Hosting Restrictions Not applicable; it runs as a zero-install browser app with BYOK model access, not a hosted service with tiers.

License Key Required No — you supply your own model provider API key (BYOK) rather than a license key for the app itself.