A hands-on tutorial for developers who want to extend Claude with a reusable, file-based skill that triages Gmail receipts and files them in Google Drive.
I lose receipts. Not paper ones — digital ones. Stripe invoices, AWS bills, the Apple developer renewal, the random SaaS subscription I forgot I had. They sit in Gmail forever, then in March I spend a Saturday rummaging through search queries trying to assemble a year of expenses for my accountant.
This year I decided to fix it with a Claude skill. The result: I type "file my receipts from last month" and Claude reaches into Gmail, pulls PDFs, drops them in the right Google Drive folder, and appends a row to a CSV log. It works because the skill tells Claude exactly how I want this done — once, in a file, forever.
This post walks through building that skill from scratch. If you've never made one before, this is the gentlest possible on-ramp. By the end you'll have a working skill you can adapt to whatever email-and-Drive pipeline you actually need.
What a Claude skill actually is
