Troubleshooting: Google API "Precondition check failed" Error

Problem Symptoms

Problem Symptoms

When attempting to send or sync mail from a Google-connected account (Grant), you receive an error from the Nylas API containing the following message from the Google API.

This error message typically occurs when the Google API returns a "precondition check failed" message to our API service. Example:

 400 error - Precondition check failed.

Resolution

Since Google does not provide granular detail for this general error, follow these steps to ensure the Grant's underlying account meets all prerequisites for the requested API action.

1. Your trial period could have expired (if you use one). Check your status at admin.google.com
2. There is no email address that you use in the FROM field created in your G Suite.
3. Your email address is not a Gmail account. It is possible to be a Google Account but not a Gmail account (for example, if you use the account for YouTube but have never enabled Gmail).
4. You may need to enable the Gmail feature or Gmail API access in your G Suite.
5. Ensure this is NOT a service account
6. Ensure the APP is trusted in the Google Workspace account.
7. Make sure this is the PRIMARY account, not impersonating / alias

Updated October 20, 2025 20:49