This custom split keyboard runs RMK, a modern and powerful firmware that supports flexible layouts and advanced features. It also has full support for Vial, enabling real-time key remapping and customization without needing to recompile firmware.

• RMK Firmware – Lightweight and modular firmware designed for custom keyboards
• Vial Support – Modify keymaps on the fly through a user-friendly GUI
• Split PIO Support – Uses RP2040's Programmable I/O to handle split communication cleanly
• 4 Layers – Plenty of flexibility for productivity, gaming, or layered macros
• Powered by RP2040 – Fast dual-core microcontroller with ample I/O and memory

These config files define the keyboard layout and Vial settings:

keyboard.toml	vial.json

This is what it looks like inside the Vial app once your board is recognized:

This build is based on the open-source 40%-ish Split Keyboard by capitaoananas. It’s a compact layout with just enough keys for productivity while keeping your desk clean and your fingers closer to home row.