I keep getting these notifications from Google, that “less secure” access is going away May 30:
https://support.google.com/accounts/answer/6010255?rfn=1651196585577&anexp=nret-fa&pli=1
Pardon if this has already been answered, but I cannot find whether Home Assistant has addressed this issue, and when I look at Google’s security checkup, HA is the one app listed as risky.
Does anyone know for sure if HA will work with this? I use it for Calendar integration, primarily.
That support article says that 3rd party apps that use your username and password to sign in are going away. Home assistant does not use your username and password.
In the security checkup, it says something else: “These apps or services have extensive access to your personal information and their developers’ information hasn’t been verified by Google.”. In this case, you are the developer as you have created this oauth credential and you have not verified your identify with Google. You can click the link in the security center to see what the risks are, but again keep in mind thi is referring to yourself and your own home assistant instance for you to evaluate, but there isn’t necessarily anything to fix here.
I’m not sure these two topics are related, unless you have more information.
I don’t know anything, that’s why I’m asking. 
Generally Google seems to send these kind of things only to affected accounts. I guess it is due to me having the “Less Secure Apps” setting turned on. I don’t remember why I turned it on if not for HA.
Anyway, thanks for the reply.
So I’ve done some testing. I’m receiving these messages because “less secure app access” is turned on, which yes lets an app access your account via username and password.
It appears my main impact as far as HA goes is SMTP email notifications. With that setting off (which it will be on 5/30 regardless) it no longer worked. However, I was able to get it to work again using the App Passwords, as per here: Sign in with App Passwords - Google Account Help
Hope this helps anyone else.