The ESP8266 module can be used as a general purpose digital pulse counter device for various digital sensors. Think about optical sensors with a digital output. To be used for things like gas, water, electricity, door open/close counters, etc.
In this example we will connect an inductive proximity switch (LJ12A3-4-Z.)
A LJ12A3-4-Z module can be used in order to detect metal. For example in your water consumption meter.
Use the schematic above in order to connect the sensor to an ESP8266 module.
Use the device tab on the ESP Easy web interface and create a new task by editing one of the available tasks. Select "Pulse Counter" from the dropdown box
Enter the IDX found in the Domoticz device page. Also select the GPIO pin that you have used to connect the pulse counting device. That should be all.
Links to other pulse counter usages
Generic pulse counter for small amounts of water.