WireMock : Free and Open Source tool for building mock APIs. Create stable development environments, isolate yourself from flakey 3rd parties and simulate APIs t...
npoint.io : JSON storage bins with schema validation
Flagr : Flagr is an open source Go service that delivers the right experience to the right entity and monitors the impact. It provides feature flags, experime...
httpbin.org : A simple HTTP Request & Response Service.
Postal : Postal is a complete and fully featured mail server for use by websites & web servers. Think Sendgrid, Mailgun or Postmark but open source and ready f...
Mockoon is the easiest and quickest way to design and run mock APIs. No remote deployment, no account required, free and open-source.