GemCoder

GemCoder is a agentic coding tool that lets developers define, run, and improve their own agentic coding harness as code. Each repository owns its harness through version controlled files. GemCoder orchestrates between Google's Managed Agents API in the cloud and the Antigravity SDK on your laptop, same engine, two runtimes, your choice per task. These files define the agent’s instructions, reusable skills, allowed context, verification commands, approval policy, and runtime routing. GemCoder turns that harness into a repo-aware workflow for the Gemini and Google Managed Agents stack, with safe context mounting, structured task packets, patch-first outputs, local verification, run graphs, and support for local or remote execution. The TUI streams agent steps and tokens live, highlights diffs, and previews patches before applying.