Ion is a coding harness that runs entirely in a Chromium tab with no install and no terminal

GitHub / fredconex (via r/LocalLLaMA)·low signalXBlueskyLinkedInCopy link

Posted to r/LocalLLaMA on 2026-09-11 (github.com/fredconex/Ion, created the same day, 8 stars), Ion is a single agent.html file you open in a Chromium-based browser and point at any OpenAI-compatible server. The constraint is the pitch: it works only inside a folder you grant via the File System Access API, has no MCP and no terminal, and therefore cannot reach outside that folder, with checkpoints to revert file changes. The author frames it as deliberately weaker than Pi, for quick edits including from a phone browser, which is a different tradeoff from the sandboxing-after-the-fact approach most harnesses take.