# Robustness 
Every API implementation and API consumer MUST follow Postel's law:

> _Be conservative in what you send, be liberal in what you accept._
>
> _– [John Postel](https://en.wikipedia.org/wiki/Robustness_principle)_

That is, send as little as possible and be tolerant as possible while consuming another service ([tolerant reader](https://martinfowler.com/bliki/TolerantReader.html)).