Handler

Handler is a desktop application that helps developers review and understand AI-generated code changes. It acts as an intermediary between you and your AI coding agent (like Codex or OpenCode). Instead of receiving a massive block of code to review all at once, every single edit the AI suggests comes with a built-in explanation. You can question any specific change in its own dedicated chat thread, which keeps the main agent's context clean and focused on its primary task.

The tool stands out by giving you granular control over AI-generated code. It includes a terminal that the agent can read directly, eliminating the need to manually paste error logs. You can screenshot any part of your screen and hand it to the agent for context, and switch between different AI models without losing your conversation history. It also uses isolated worktrees to prevent agents from interfering with each other's work.

Handler is particularly valuable for developers who regularly use AI coding assistants but want to maintain code quality and understanding. It's useful for reviewing large refactors, understanding complex AI-generated solutions, or debugging issues where the AI needs to examine terminal output directly. It helps prevent 'AI slop' from entering your codebase by making every change explainable and debatable.