I'm building an open-source, Pix-inspired instant-payment foundation in Rust - and it needs contributors

In 2020, the Banco Central do Brasil introduced Pix, an instant payment system that allows users to send money to anyone in Brazil using only their email or phone number. This innovative payment method quickly gained popularity, surpassing traditional card payments due to its speed and ease of use. However, most other markets lack a similar unified payment infrastructure, often relying on multiple intermediaries and slower processes when transferring funds across providers or borders.

To address this issue, the author has developed raio, an open-source instant-payment foundation written in Rust. The design of raio is built on the principle that its core remains IO-free, ensuring determinism and easy fuzzing for robust testing. The foundation provides a set of traits for ledger storage, key directories, and settlement providers, allowing developers to implement these components in their preferred way without interfering with the core's trust foundation.

raio includes two QR code implementations that adhere to the same structure, regardless of the payment rail being used. This enables seamless interoperability with various mobile-money providers and banking applications. For instance, the author has created two pure-Rust QR codecs, raio-brcode and raio-qr, which can be utilized independently of raio-core and are suitable for continuous fuzzing to ensure security.

To summarize, raio aims to create a solid foundation for instant payments that can be easily extended by other providers, ultimately fostering a more interconnected and efficient global payment system.