REA is an open-source toolkit for reverse engineering. It lets agents inspect apps, binaries, and runtime behavior. It works with native binaries, JavaScript, Electron, .NET, and websites. Analysis runs locally and returns evidence with each conclusion. Setup registers REA with an agent and adds workflow instructions. It supports Claude Code, Cursor, Gemini CLI, and others. Native analysis needs Hopper, Ghidra, or IDA. Static JavaScript analysis needs no extra engine. The project is under an MIT license.