Gmail API costs and client secret file expiration

Other Questions Gmail
1

I have a .NET application that connects to Gmail using the API with a client_secret.json configuration file. I’m wondering about a few things related to this setup.

First, are there any charges for using Gmail’s API? I want to make sure I understand if this service is completely free or if there are usage fees I should expect.

Second, I’m curious about the client_secret.json file itself. Does this file have an expiration date? Will I need to regenerate or update it after a certain period of time?

Any insights about Gmail API pricing structure and the lifespan of the client secret configuration would be really helpful for planning my project.

2

Gmail API uses Google’s standard quotas - no direct billing for most cases. You get plenty of free quota that’ll handle typical apps, though heavy enterprise use might hit paid tiers eventually. Your client_secret.json file stays valid forever unless you manually delete or regenerate the OAuth credentials in Google Cloud Console. I’ve run apps with the same client secret files for 2+ years without problems. User tokens from OAuth flow refresh themselves, but the client secret doesn’t expire. Just back up the file - losing it means redoing your entire OAuth setup.

3

Gmail API is free under Google Workspace APIs with generous daily quotas. You’d need massive volume to hit paid tiers, so cost isn’t an issue for most apps. About the client_secret.json file - here’s what matters: The client secret doesn’t expire, but your access tokens do and need refreshing with refresh tokens. Your client_secret.json stays valid forever unless you revoke or regenerate credentials in Google Cloud Console. I’ve run production apps with the same client secret files for years without problems. Main risk is accidentally deleting or corrupting the file - then you’d have to recreate OAuth 2.0 credentials and potentially re-authorize users.

4

gmail api is mostly free, but keep an eye on daily limits. as for the client_secret.json, it wont expire on its own unless you change oauth settings or revoke access. mine’s been good for like a year now.