The Operator SDK lets you build MIDI processing and UI modes that the Operator device loads dynamically from its /global/ and /output/ folders. A mode is a small, position-independent ARM binary that plugs into the device's real-time MIDI pipeline and talks to the firmware through a stable, append-only function-table ABI. You never rebuild or reflash the firmware to add one. You drop a .opm file onto the device and load it.

New here? Start with Getting Started. To understand the device before writing code, read How Operator Works.

Start here

Getting Started (install the toolchain and build your first mode)

Concepts

How Operator Works (the two cores, the MIDI signal chain, global vs output modes)
Mode Lifecycle (the hooks, and how a mode becomes a live callback)

How-to

Processing MIDI (read, transform, drop, and generate MIDI: the core of a mode)
Parameters (declaring parameters, reading them, and how they persist)
Custom UI (drawing your own screen and handling input)
Timing and Clock (a smooth position from the clock, and generating or consuming it)
Storage and Files (reading files, the FilePicker)
The Mode Mindset (the constraints that shape every mode, and why)
Debugging (the on-device MIDI monitor, the Log Monitor, and common build failures)
Testing (test your mode's logic on your computer, no hardware needed)

Reference

ABI Reference (the OperatorApi function table and the gesture ABI)
.opm Format Reference (the .opm header, parameter table, and flags)
Build Reference (prerequisites, op_add_mode(), the toolchain files)

The per-symbol API reference generated from the headers is under Namespaces, Classes, and Files in the sidebar.