Implementing Stripe Checkout Billing in PatentLLM

Introduction To commercialize PatentLLM, we implemented a billing system using Stripe Checkout. Existing FTS5 search, web search, and analysis prompts were already complete. The remaining challenge was to "build a billing gate." Design Policy: Do Not Hold Card Information Reasons for Not Directly Calling the API We considered directly calling the Stripe API to handle billing, but decided against it. Managing card information on the server increases security risks. Risk of the entire application becoming unusable during payment errors. Adoption of Stripe Checkout We adopted a method where a "Subscribe" button is placed within the application, transitioning the user to Stripe's payment screen. Card information is managed solely by Stripe (not held on our server at all). Subscription status is cached in local SQLite upon successful payment. Handles network failures with fallback to Stripe API. Implementation Highlights Graceful Degradation import os import stripe stripe_key = os.getenv (