Download & installDownload and install locally. No server needed.
ZMK Firmware Repository
KeyboardsEmbeddedFirmware
From the README
ZMK Firmware is an open source (MIT) keyboard firmware built on the Zephyr™ Project Real Time Operating System (RTOS). ZMK's goal is to provide a modern, wireless, and powerful firmware free of licensing issues.
Alternative firmware for ESP8266 and ESP32 based devices with easy configuration using webUI, OTA updates, automation using timers or rules, expandability and entirely local control over MQTT, HTTP, Serial or KNX. Full documentation at