SMS API with a sandbox/test environment

I need an API for SMS sending that has a sandbox/test environment. What I mean is that i should be able to initialize the api with some option sandbox = true or with a sandboxed api key so that in this case the messages are not sent but they can be browsed is some kind of interface for testing/reviewing purpose. Much like you do with things like mailtrap.io

P.s. many SMS API providers have dropped such features saying: you can use inversion of control to build your own sandbox!!1 I don't want to discuss the... logic (or lack thereof) of this reasoning, but this is not what I'm looking for and it's not an acceptable solution.