Off-the-shelf energy monitor?

I am looking for a ready solution for 1-phase energy monitoring. There are several DIN rail or small modules with CT on aliexpress but they advertise Tuya and might not work with HA.

Maximum current would be 32A, which is never seen, I am more interested in accurate low-current monitoring. Hopefully something that can also update pretty fast (1-3 sec).

Examples: - might not work with HA - might not work with HA
Shelly - Shelly - quite expensive

I could go the DIY route and buy something like Mottramlabs-Products, a CT and pair it with one of my many NodeMCU/D1 modules, if that’s the way you recommend.

Provide some more clarification:

Do you want DIN rail?
Does it matter what protocol it is? (WiFi / Zwave / Zigbee)
Input voltage
What you want to monitor

Space: I can fit 1-DIN (18mm) only or I can leave it around in the panel, there’s enough space for a 50x50x50 box with wires.
Protocol: I can do WiFi and Zigbee and 433.
Voltage: 220V
Purpose: Long-term whole-house power consumption, instant power, being able to see differences of 5W (e.g. if something is unplugged). A split CT is more useful since I can switch to different circuits, for example monitoring just lights or garden.

I’ve looked around a bit more, seems that the moderately expensive Shelly EM is the most effective way. The other option is DIY, but unless I’m going with a custom PCB it’s going to take up more space and possibly be less safe.
All the options listed on the energy integrations (Integrations - Home Assistant) page are more expensive and most of them require some proprietary cloud API.
There are some offers on tindie but no complete solutions, just a step up from raw DIY.

The better DIY solution would involve a board with ESP8266/EP32 (2-5$) + micro supply (2-5$) + PZEM module and CT clamp (8-12$). A cheaper but worse solution would be to just interface a CT clamp and a voltage sensing circuit and let the ESP ADC collect the data and do the integration.

This is a screenshot of the Mottram labs 4 Channel Power Sensor V3 that I have just set up on the ESPHome dashboard of HA. I now have to get a voltage monitor set up and connected then add these to the energy dashboard!

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