Variables
The checklist lists
GOOGLE_WEBHOOK_AUDIENCE among the missing names as long
as it is empty: connections work without it, incoming Gmail notifications do
not.
Creating the client
- Google Cloud Console → a project → APIs & Services.
- Enable what your agents will use: Drive API, Gmail API, Calendar API, Sheets API, Docs API.
- OAuth consent screen: External unless everyone is in your Workspace. While the app is in Testing, only listed test users can connect, and refresh tokens expire after seven days — publish it before rolling it out.
- Credentials → Create credentials → OAuth client ID → Web application.
Authorised redirect URI:
https://your-host/integrations/google/callback. - Copy the client ID and secret.
Gmail push notifications
Beyond the client, Gmail triggers need a Pub/Sub topic —GMAIL_PUBSUB_PROJECT_ID
and GMAIL_PUBSUB_TOPIC — and GOOGLE_WEBHOOK_AUDIENCE, the value the handler
verifies before acting on a notification. Full walkthrough:
Gmail webhooks.
Check
Integrations → Google Drive → Connect.redirect_uri_mismatch means
the URI registered in the console differs from the one the server sends —
compare them character for character, including the scheme.