Sbt

Spec scala code generation is packaged in form of SBT plugins. Add sbt-specgen plugin library into the sbt project using following line in the plugins.sbt:

addSbtPlugin("io.specgen" % "sbt-specgen" % "<version>")

Instead of <version> use latest available from Maven Central Repository.

Play Service

Spec code generation has full support for Scala Play applications. Models, controllers, services traits and services scaffolded implementations are generated by SpecPlay plugin.

To enable server side code generation from spec enable SpecPlay plugin in your build.sbt:

enablePlugins(SpecPlay)

Following dependencies are defined in SpecPlay and should be added into libraryDependencies:

libraryDependencies ++= specPlayDependencies

Specgen plugin generates router that should be pluged into conf/routes:

#  spec routes
-> / app.SpecRouter

Here are SpecPlay settings that allow customization of code generation:

Setting	Default	Description
specFile	spec.yaml	Path to service specification file; relative to project folder
specSwagger	public/swagger.yaml	Path to generated OpenAPI/Swagger specification file
specGeneratePath	target/scala/src_managed/main/spec	Path to generate source code into
specServicesPath	app/services	Path to scaffolded services files; these services are scaffolded only if they do not exist

Default settings are aligned with the standard Play application layout.

Generated swagger (OpenAPI) documentation could be hosted. Following routes should be added to conf/routes:

#  documentation
GET  /docs              controllers.Default.redirect(to="/docs/index.html?url=swagger.yaml")
GET  /docs/swagger.yaml controllers.Assets.at(path="/public", file="swagger.yaml")
GET  /docs/*file        controllers.Assets.at(path="/public/lib/swagger-ui", file)

This setup above hosts swagger documentation at /docs route of the Play application.

Sttp Client

Spec code generation can generate HTTP client in Scala based on spec. The generated client is using sttp client under the hood with provided ability to plugin backend of your taste.

To enable client code generation from spec enable SpecSttp plugin in your build.sbt:

enablePlugins(SpecSttp)

Following dependencies are defined in SpecSttp and should be added into libraryDependencies:

libraryDependencies ++= specSttpDependencies

Here are SpecSttp settings that allow customization of code generation:

Setting	Default	Description
specFile	spec.yaml	Path to spec file relative to project folder
specGeneratePath	target/scala/src_managed/main/spec	Path to generated code is placed

Models Circe

Spec code generation can generate only (de)serializable to JSON circe models without any application specifics.

To enable models generation from spec enable SpecCirce plugin in your build.sbt:

enablePlugins(SpecModels)

Following dependencies are defined in SpecCirce and should be added into libraryDependencies:

libraryDependencies ++= specCirceDependencies

Here are SpecCirce settings that allow customization of code generation:

Setting	Default	Description
specFile	spec.yaml	Path to spec file relative to project folder
specGeneratePath	target/scala/src_managed/main/spec	Path to generated code is placed

Under the Hood

All specgen SBT plugins are running specgen command line tool. The specgen command line tool binaries are packaged as a resource into sbt-specgen plugin jar. On any sbt-specgen plugin execution it unpacks specgen binaries from itself and executing commands using those binaries.