openapi4s

OpenApi generators for Scala.

Here is a small video demo: https://youtu.be/kf0vGrlKNb8

Features and Benefits

• incremental generator
  • doesn't touch the code that you added manually
  • only adds new properties/methods/classes
• lenient parser+generator
  • if something is not supported it will still (mostly) work
  • you can adapt your openapi spec to work gradually

Limitations

• JSON only
• only named entities, no anonymous objects

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Generators

Sharaf backend

Supports almost all features:

• controllers
• discriminated models (sealed traits)
• enums (scala3 singleton enums)
• validations
• query params

Http4s backend

Supports some features:

• routes (controllers)
• discriminated models (sealed traits)
• enums (scala3 singleton enums)

TODO: query params, validation..
Contributions welcome!

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Usage

Mill plugin

See https://github.com/sake92/mill-openapi4s

CLI

You can use openapi4s-cli with Coursier launcher to generate your sources:

cs launch ba.sake::openapi4s-cli:0.6.1 -M ba.sake.openapi4s.cli.OpenApi4sMain -- \
  --generator sharaf \
  --url openapi.json \
  --baseFolder src \
  --basePackage com.example