esphome : Make creating custom firmwares for ESP32/ESP8266 super easy. ( https://github.com/esphome/esphome https://pypi.org/project/esphome/ )
esptool : Utility to communicate with the ROM bootloader in Espressif ESP8266 and ESP32 ( https://github.com/espressif/esptool )
platformio : An open source ecosystem for IoT development ( https://platformio.org/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a HomeAssistantRepository
For Paludis use this rsync : rsync://gentoo.zugaina.org/HomeAssistantRepository-portage
If you have a problem : ycarus(-at-)zugaina.org