Rivet is a chat-first AI coding agent built native for Android. Pick a project folder, pick a model, describe the change — Rivet reads and edits files and runs commands right on your phone. No laptop, no Termux setup. Bring your own key (OpenAI, Anthropic, Gemini, OpenRouter), or sign in with a ChatGPT plan. Switch models and reasoning levels mid-chat, and undo changes with checkpoints. Free and open source.