The Language of Mantis

Every H1 payload is written in the Language of Mantis — HDC for short (HiveFusion Device Compiler), the scripting language behind every .hdc file. If you’ve used a USB Rubber Ducky before, the syntax will feel immediately familiar: short, uppercase commands, one per line, read top to bottom.

The important difference is what happens to your script before it ever reaches the device. HDC is a compiled language, not an interpreted one — when you hit Compile, HiveFusion Studio (the desktop IDE) checks your script for errors and turns it into compact bytecode on your computer. Only that bytecode is uploaded and stored on H1; the human-readable script text never touches the device. This is the same Host-Compiled Bytecode Architecture (HCBA) described in the hardware documentation, and it’s why H1 can run fairly complex payloads on a microcontroller with no script parser of its own.

HDC is deliberately simple. It has no math, no variables that change while a script runs, and no if/else branching — it’s a linear sequence of instructions, not a general-purpose programming language. That simplicity is the point: every script behaves exactly the same way every time it runs, which matters a lot when the “output” is real keystrokes typed into someone’s computer.

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