Push notifications not working for Gmail API webhook integration

Other Questions Gmail
1

I’m trying to set up automatic notifications when new messages arrive in my inbox, but the webhook isn’t getting triggered. I followed all the setup steps but something isn’t working right.

What I’ve done so far:

  1. Set up a Pub/Sub topic in my Google Cloud project
  2. Gave the Gmail service account ([email protected]) publisher permissions on the topic
  3. Created a push subscription pointing to my server endpoint
  4. Verified my webhook URL works by sending test messages through Pub/Sub directly

The weird thing is that manual testing works fine, but when I actually receive emails in my Gmail account, nothing gets sent to my webhook endpoint.

Here’s the code I’m using to enable watching:

async enableEmailWatch() {
  try {
    const pubsubTopic = "projects/myproject/topics/gmail-notifications"
    const gmailClient = google.gmail({ version: "v1", auth: this.authClient })
    await gmailClient.users.watch({
      userId: "me",
      requestBody: {
        topicName: pubsubTopic,
        labelIds: ["INBOX"],
      },
    })
  } catch (err) {
    console.error(err)
    return null
  }
}

Any ideas what I might be missing here?

2

Check your subscription acknowledgment settings. Gmail sends push notifications to your Pub/Sub topic, but your subscription must acknowledge each message within the ack deadline (defaults to 10 seconds). If your webhook doesn’t properly acknowledge the message, Pub/Sub thinks delivery failed and throttles future deliveries. Your webhook needs to return a 200 status code AND your subscription’s ack deadline should match your processing time. Also verify you’re actually getting messages in the Pub/Sub topic - go to the monitoring tab in Google Cloud Console and see if messages show up when emails arrive. If no messages reach the topic at all, you’ve got a problem with Gmail API permissions or the watch request.

3

Had the same issue - drove me nuts for weeks. Gmail’s watch request expires after 7 days by default, and it’s not obvious. You need to manually renew it or set up auto-renewal. Test this by calling users.stop() then a fresh users.watch() request. If notifications start working again, that’s your problem. I set up a cron job that renews every 5 days to stay ahead of it. Also make sure your webhook returns a 200 status within 10 seconds. Gmail’s push service is strict about response times and will stop sending notifications if your endpoint’s too slow or throws errors.

4

check if google’s servers can actually reach ur webhook endpoint. I had this same issue - turns out my local dev server wasn’t publicly accessible even tho I thought it was. Use ngrok or deploy to a real server to test. Also make sure ur pub/sub topic name matches exactly what u used in the watch request - typos there fail silently.