OpenAI released a $230 keyboard that only works with Codex. Fully closed. It's a keyboard — some switches and a microcontroller — so I built my own that same week and open-sourced everything: the PCB, the firmware, the companion app, and the 3D-printed case. Parts cost under $40. OpenMicroKbd works with any AI coding tool — Codex, Claude Code, Conol, whatever you're using that week. Hold the voice key and dictate prompts instead of typing them. Give each running agent its own key and jump between them with one press — when one needs permission, one keypress takes you straight to it. The knob controls how hard the AI thinks. At least this week it does; last month it was volume. Every key is remappable, with 24 keymap slots and profiles for coding, Premiere/Lightroom editing, and games. HARDWARE • 13× Kailh Choc V2 low-profile switches on a 19.05 mm grid, 1N4148W per-key matrix diodes • EC11 rotary encoder, RKJXV analog joystick, capacitive touch pad • Per-key RGB + underglow (S