I'm building an open-source HTTP debugger for intercepting, inspecting & mocking live HTTP(S) traffic.
I've just finished building an OpenAPI integration, so that you can add your OpenAPI spec to the tool, and see inline documentation & validation for live requests as they're sent. This works out of the box for external APIs from AWS to GitHub to Stripe (using the awesome OpenAPI directory), and also for your own APIs too.
Right now, I'm looking for testers. The tool is freemium, and bormally this would be a paid feature, but I'm happy to set all testers up with a couple of months free in return for feedback. Anybody interested? Just leave a comment below :-).
Here's some screenshots from the public API validation, so you can see how it works: