Azure API management policy toolkit is a set of libraries and tools for Azure API Management which target policy document. The toolkit was design to help create and test policy documents with complex expressions.
Before the Policy toolkit, policy documents were written in Razor format. The Razor format is hard to read and understand, especially when there are a lot of expressions. The feedback loop on new documents or event the smallest changes was very long. It required live Azure API Management instance, a policy document deployment and manual testing through the API request.
The policy toolkit changes that. It allows you to write policy documents in C# language. The C# language is more natural and shows a process nature of policy. There is as well, no need to jump between C# and XML for expression creation. Creating policy documents in C# brings another advantage. Simple C# code can test the policy document in the unit test.