todokr / zugen   2021.12.0


An architecture diagram generator for Scala project.

Scala versions: 2.12
sbt plugins: 1.0


Build Status Maven Central


An architecture diagram generator for Scala project.

Documents to be generated

These following screenshots are generated in the example Scala project.

Domain object table

A table of domain objects under the specified packages.
This is useful as a glossary of domain terms.

  • List package, class/trait name, scaladoc and file path
  • Jump to GitHub source

Domain object table

Domain relation diagram

A diagram which indicates relation among domain objects.

  • Show class/trait name with its alias in scaladoc
  • Show inheritance relations
  • Show properties
  • Highlight references which is bound to outside of domain package in red
  • Show argument names of constructors as labels on edges
  • Jump to GitHub source

Domain relation diagram

Method Invocation Diagram

A diagram which shows method invocation chain.

  • Show project-internal method invocations
  • Show invocations of external libraries
  • Jump to GitHub source

Method invocation diagram

Getting Started



addSbtPlugin("io.github.todokr" % "sbt-zugen" % "2021.12.0")


domainPackages=example.domain                   # Package name which represent domain
domainObjectExcludePatterns=".+Repository"      # Regex patterns to exclude classes from domain relation diagram
methodInvocationRootPackage=example.controllers # The root package of method invocation diagram
key description available values default example
documentsToGenerate Document types to generate.
If empty, generates all kind of documents.
empty documentsToGenerate=domain-object-table,domain-relation-diagram,method-invocation-diagram
domainPackages Package names which represent domain. comma separated string empty domainPackages=app1.domain,app2.domain
domainObjectExcludePatterns Regex patterns to exclude classes from domain relation diagram. comma separated string empty domainObjectExcludePatterns=".+Repository"
methodInvocationRootPackage The root package of method invocation diagram string empty methodInvocationRootPackage=controller
documentPath Directory to output documents string target/zugen-docs documentPath=docs
githubBaseUrl The base URL of source code in GitHub repository string empty githubBaseUrl=


Zugen loads source code information from SemanticDB. There are 2 ways to enable SemanticDB file generation.

Using sbt option

From 1.13, sbt supports SemanticDB generation.

ThisBuild / semanticdbEnabled := true
ThisBuild / semanticdbVersion := "4.4.33"
scalacOptions ++= Seq("-Yrangepos", "-P:semanticdb:text:on")
Using compiler plugin
addCompilerPlugin("org.scalameta" %% "semanticdb-scalac" % "4.4.27" cross CrossVersion.full)
scalacOptions ++= Seq("-Yrangepos", "-P:semanticdb:text:on")


$ sbt zugen

Then, zugen diagrams are generated under the directory specified with documentPath setting (default is target/zugen-docs).

If any question you have, please feel free to contact me on Twitter.


Zugen is inspired by JIG, which is a document generator for Java project and its philosophy.