We are excited to launch our new TfL Oyster app on iOS and Android, which allows customers to top up their Oyster cards, purchase Travelcards and view their journey history. The app was launched last week, and has already received lots of great feedback. We wanted to offer you more insight into how we developed it.
An API – or application programming interface – is a set of subroutine definitions, protocols and tools for building application software¹. We already have a wide range of public APIs, which provide information such as line status, bus status and journey information. To build a mobile application allowing customers access to their Oyster card data through, we needed to write a new API to support this.