typed-protocols VS cardano-node

Certain correctness properties of code can be ensured statically, i.e. at compile time. Those checks rely on the programming language's type system. Software engineers can take advantage of type safety features to implement components in a way that makes them safe by construction. For example, Cardano uses the typed-protocols package, a generic framework for implementing application-level protocols, which is based on a simple form of session typing.6 Within this framework, protocols are described as state machines encoded into Haskell types. The allowed transitions between states correspond to messages exchanged between the peers, so the protocol state determines which messages are allowed to be sent or must be accepted when received, at type level. This simplifies protocol implementation, allows early detection of protocol violations, and makes the protocols themselves deadlock-free by construction. More advanced type-level programming techniques may allow achieving impressive levels of type safety; however, such code may be significantly harder to implement, understand, and maintain.

I like to use typed-protocols for this: https://github.com/input-output-hk/typed-protocols/

Cardano — a blockchain platform based on the Ouroboros family of consensus protocols (written in Haskell).