A while back I made a blog post titled, Tools For The Modern Day Developer, in which I listed the tools I thought at the time every developer should be using. Today, I still stand by that list, but I would like to add an additional tool that lately has become super useful to me, that tool is Mockoon.


Mockoon is a free and open-source mock API tool created by Guillaume in 2017. It offers Docker support, a CLI, importing and exporting of Mockoon environments, it works with OpenAPI 3.0 files. In many ways it feel like Postman, even the UI feels like the old classic Postman UI.

I have been using it for the last few months at work and on side projects. It has allowed me to create powerful mocks around service that may not have a sandbox as well as for local development. Instead of spinning a bunch of services locally for debugging, I only run the servie I’m actually working on, all external API calls are mocked.