OneGadget is a specialized tool designed for CTF pwn challenges that identifies RCE (remote code execution) gadgets capable of executing execve('/bin/sh', NULL, NULL). The tool employs symbolic execution techniques to analyze binary files and determine the constraints required for gadgets to function successfully. It supports multiple architectures including i386, amd64, and aarch64. OneGadget provides a command-line interface with various options for customization. Users can specify build IDs, force file searches, control output verbosity levels, and order gadgets based on their proximity to specific functions or files. The tool is distributed through RubyGems.org for easy installation and integration into security testing workflows. It focuses specifically on finding gadgets that can spawn shell access, making it particularly useful for exploit development and binary exploitation scenarios.