We have a separate web api project which consists of REST end points consumed by our different web applications(ASP.NET ,Mobile, PHP etc).
Now we have a situation that we want to expose our some of API's with our partners. For example I want to expose 2 API's one will give all recipes in our system and other will give detail of each recipe. We want to implement some of kind of security so that they can be only used by our partners not by anyone else.
Can somebody suggest us what kind of security is best for this use case.