Show HN: OpenGravity – A zero-install, BYOK vanilla JS clone of Antigravity

· devtools web ai-agents · Source ↗

TLDR

  • Browser-based, zero-install Antigravity UI clone built in pure HTML/CSS/JS with BYOK Gemini support, xterm.js terminal, WebContainer API, and a sidebar agentic coding loop.

Key Takeaways

  • Zero-install IDE: Served via python3 server.py; no npm for the IDE itself. Uses WebContainer API for a real Linux-like terminal in-browser.
  • Gemini-only BYOK: Supports gemini-3.1-pro-preview and flash variants; API key stored in localStorage. Provider is hardcoded in agent.js:8.
  • Alpha-quality agent: Can initialize projects, run pnpm, edit files, and handle interactive terminal prompts. Orchestration logic is basic; multi-agent handling not yet implemented.
  • Known gaps: Model dropdown hardcoded, Git icon is a placeholder, top menu bars (File/Edit/Selection) are stubs, no settings panel beyond a small icon.
  • Maintenance cadence: Author is sitting GCSEs; PRs reviewed Sunday evenings only.

Hacker News Comment Review

  • Discussion is minimal. The author clarified the primary use case is quick in-browser HTML/CSS/JS prototyping without spinning up a full dev environment or hitting Antigravity rate limits.
  • One commenter suggested the name ZeroGravity better fits the project’s design goals; the author agreed and may rename post-exams.

Original | Discuss on HN

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