Google//Gmail API

REST API for programmatic access to Gmail mailboxes — read, send, label, search, and manage email without the Gmail UI.

REST API for programmatic access to Gmail mailboxes — read, send, label, search, and manage email without the Gmail UI.

Having Gmail API in your service is like having an appendix of Google in your app. The user talks directly to Google: gives permission via OAuth 2.0, and Google hands your app a token to access that user's data. Your app never sees the user's password — just the scoped token Google gave you.

OAuth 2.0 scoped access: read-only, send-only, or full access. Users must consent explicitly.

Common uses: automated email parsing (invoices, receipts), CRM integrations, notification systems, email migration tools

Watch API: push notifications via Google Cloud Pub/Sub when new mail arrives — no polling needed

Quotas: 250 sends/day for regular accounts, higher for Workspace. Rate limits per user and per project. For heavy batch processing (e.g. scanning thousands of emails), a Vercel Function will timeout — you need a job queue like Inngest or Trigger.dev to process in chunks.

Not SMTP: the Gmail API is HTTP/JSON-based. For SMTP relay (legacy apps, printers, IoT devices), Gmail's SMTP server is a separate thing.

Managed through Google Cloud Console (API enablement, credentials, quotas)