What is akamai-vm?

This repository is a decompiler for Akamai's bot-detection system, which is used by websites like Hilton to tell apart real visitors from automated bots. Akamai protects itself partly by running obfuscated JavaScript inside a custom virtual machine, essentially a small, hidden computer running inside your browser. This project reverse-engineers and decompiles that virtual machine back into readable code. A virtual machine in this context is a simple interpreter: it reads a sequence of instructions (opcodes) one at a time and executes them, using a stack (a temporary scratch space where values are pushed on and popped off) to pass data between operations. The author describes Akamai's VM as having a fairly straightforward architecture, taking about two days to analyze and implement a decompiler for. The main interesting features were a property-resolution system where the VM searches down the stack to find a named value, and an exit mechanism that deliberately calls a non-existent opcode to terminate, relying on a try/catch wrapper in the main loop to silently swallow the resulting error. The decompiler works by reading the VM bytecode, constructing a control-flow graph (a map of how different code paths connect), and then applying cleanup passes like inlining and collapsing to produce cleaner output. It is a static decompiler, meaning it analyzes the code without running it, and does not include a parser for the raw bytecode format, the intention is to share decompilation techniques rather than provide a complete end-to-end tool. The project is stated to be for educational and research purposes.