WireMock : Free and Open Source tool for building mock APIs. Create stable development environments, isolate yourself from flakey 3rd parties and simulate APIs t...
Matrix : Matrix is an open standard for decentralised communication, providing simple HTTP APIs and open source reference implementations for securely distribu...
DuckRails : DuckRails is a development tool.
Its main purpose is to allow developers to quickly mock API endpoints that for many possible reasons can't reach at a...
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...
Cool QL Cool : CoolQLCool (CQC) is an open source GraphQL server that allows you to turn websites into GraphQL APIs.
Mockoon is the easiest and quickest way to design and run mock APIs. No remote deployment, no account required, free and open-source.