RestClient.Net makes HTTP calls in .NET easy. Send the request body as a strongly typed object, and get back a strongly typed object. You can inject the abstraction into your service classes and quickly mock them without worrying about the HTTP plumbing or converting to JSON. RestClient.Net 5 is a much improved, battle-hardened version that builds on the approach of V4 while introducing immutable types and a fluent API. It reduces the chance of shooting yourself in the foot with HttpClient, plays nicely with dependency injection, integrates with Polly, and the design should be familiar and comfortable to F# programmers.