Auto Flight Price Tracker Extension for Google Flights

I need a lightweight Chrome extension that watches my Gmail inbox for any new confirmation coming from the Chase Travel Portal, pulls out the key itinerary details (flight dates & times, airline + flight number, price and each traveler’s name) and immediately creates a matching Google Flights price-tracking alert in the background.

As soon as the alert exists, the extension should also inject a small overlay on the Google Flights “Tracked prices” page so I can see, at a glance, the original paid fare and the traveler tied to that booking. If the Google Flights graph later shows a drop, I’ll know it is time to request a refund or credit.

Core flow
1. Gmail watch: on every new email from the Chase Travel Portal, parse the message with the Gmail API / chrome.identity token and extract the fields listed above.
2. Alert creation: hit the public Google Flights deep-link endpoint (or simulate the UI) to start price-tracking for the exact route and dates.
3. UI overlay: via a content script, add a concise row or badge beside the tracked leg showing “Paid $X – Traveler: Name”.

Acceptance criteria
• A new Chase confirmation triggers the alert automatically within a few minutes.
• Overlay shows in both list and detail views on Google Flights.
• No manual input is required once the extension is installed and authenticated.
• Code is clean, commented and packaged so I can load it in Developer Mode for testing.

Let me know any API limitations you foresee and the rough structure you plan (background.js, content scripts, OAuth scopes, etc.) so we can keep the first build simple and privacy-respectful.