Could be! It's all open-source but actually not all AGPL: the core desktop app is, but the internal libraries like https://github.com/httptoolkit/mockttp https:

Could be! It's all open-source but actually not all AGPL: the core desktop app is, but the internal libraries like https://github.com/httptoolkit/mockttp https://github.com/httptoolkit/mockttp are generally MIT or Apache 2, so if you're looking to dig into and use those internals, it's pretty thoroughly unencumbered. It's really just the runnable desktop app part that's AGPL. That encumbers you if you're making a directly derivative work (no running off with the whole app but closing the source, thank you), but otherwise it shouldn't limit you at all. This isn't like using a (A)GPL library in your codebase; it's a full application and you're an end user.