During July 2025, Xcd developed TypeScript typings for the new issuingAddToWalletButton feature in the stripe/stripe-js repository. Their work focused on defining robust type definitions and element options, enabling safer and more predictable integration for developers adopting the Issuing Wallet flow. By introducing comprehensive usage tests, Xcd ensured type safety and reduced the risk of runtime errors, directly improving the developer experience. The implementation leveraged TypeScript and API development skills, emphasizing a typing-first approach to new features. This contribution deepened the API’s type coverage, streamlining integration and accelerating adoption of the wallet button for teams using stripe-js.