Track Email Opens From Your Agent's Outreach

You built an outreach agent, it sent 80 follow-ups this week, and you have no idea what happened to any of them. Did the prospect open the message? Click the demo link? Is the silence a "no" or a spam-folder problem? Without engagement signals, your agent is firing into the void and your follow-up logic is guesswork. The fix has two parts: turn tracking on when you send, and subscribe to the webhooks that report what recipients do. Tracking starts at send time, not after Opens, clicks, and replies are only reported for messages sent with tracking enabled — you can't retroactively track a message that's already out. On the Send Message request, pass a tracking_options object with three booleans plus an optional label that gets echoed back in every notification: curl --request POST \ --url 'https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/messages/send' \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer <NYLAS_API_KEY>' \ --data-raw '{ "subject": "Quick follow-up on your trial", "body": "Thanks for trying us out. Reply or <a href=\"https://example.com/demo\">book a demo</a> when ready.", "to": [{ "name": "Kim Townsend", "email": "kim@example.com" }], "tracking_options": { "opens": true, "links": true, "thread_replies": true, "label": "trial-followup-q2" } }' The label is the piece agents should lean on: stamp it with your campaign ID or contact ID and every later notification carries it, so your handler matches events back to outreach state without storing a message-ID mapping. One caveat before you test: message tracking needs a production application — trial accounts get "Tracking options are not allowed for trial accounts" back. Three triggers, one endpoint Engagement events arrive over webhooks. Subscribe one HTTPS endpoint to all three triggers — message.opened , message.link_clicked , and thread.replied : curl --request POST \ --url 'https://api.us.nylas.com/v3/webhooks/' \ --header 'Content-Type: application/json' \ --header 'Autho