Firebase Phone Auth price

Question

Firebase allow free 10k authentications/month + 0.06 per each extra authentication. I am reading a documentation however it is still not clear to me what authentication/validation definition is.

Does that mean I can receive 10k free sms messsages per month and I will pay nothing extra when user already logged in and uses APIs to call firebase services OR it means I will need to pay extra even after user successfully logged in but in case of firebase internally wants to validate authentication status as kind of a background task is considered authentication too?

In other words: let's say each month I have 10k new logins (sms received) should I expect to be charged anything extra?

Answer 1

Firebase Auth only charges on successful verification. So if a user tries to sign in with a phone number and an SMS code is sent but not used or received by the user, this attempt will not be counted. Only when user enters the code and successfully verifies it (successfully signing in), will that attempt count. The first 10k successful verifications are free. Any successful verification afterwards will be $0.01/verification for US/Canada/India and $0.06/verification for other countries.