A few years ago I built my own boards to monitor AC availability in my home. I used one board per main circuit branch (I.e. a group of circuits protected by a common GFCI). I based my design on the MID400 AC Line Monitor Logic-Out Device. This chip, with the addition of 2 resistors detects the presence of AC and raises/lowers a 5vdc output to track the AC. I just fed the 5v signal into an I/O board and was done. These have served me well for the past 6 years. But, the boards were fairly large and I would have preferred something denser, and commercial.
Now I have another application for AC sensing (detecting the operation and direction of an electric gate motor). So, I started searching around again to see what was available. There are some new chips on the market. But, still pretty much what I already had. Then on YouTube I found this board. It has 8 AC inputs and 8 opto-isolated outputs. Perfect. The same board is also available in a 1 and 3 circuit (as shown in the video) configuration and can be found in Europe as well as Asia.
Note, this is not a current monitor or a voltage monitor. It simply detects the presence of AC. But, if you have a mission-critical system, like animal monitoring and feeding, etc., and you need feedback that something has actually operated, this may be exactly what you need.
WARNING: As the video makes very clear, you need to use this board very carefully as it has exposed AC line current on it. I will attach a backing board and then mount a small bit of plastic over the high-voltage area as well as enclose the board in an electric box.