Swagger Codegen Generators

If the default generator configuration does not meet your needs, you have various options to modify or create new modules or templates.

Modifying the client library format

Don’t like the default swagger client syntax? Want a different language supported? No problem! Swagger Codegen processes mustache templates with the jmustache engine. You can modify our templates or make your own.

You can look at modules/swagger-codegen/src/main/resources/${your-language} for examples. To make your own templates, create your own files and use the -t flag to specify your template folder. It actually is that easy.

Making your own codegen modules

If you’re starting a project with a new language and don’t see what you need, Swagger Codegen can help you create a project to generate your own libraries:

java -jar modules/swagger-codegen-cli/target/swagger-codegen-cli.jar meta \
  -o output/myLibrary -n myClientCodegen -p com.my.company.codegen

This will write, in the folder output/myLibrary, all the files you need to get started, including a README.md. Once modified and compiled, you can load your library with the codegen and generate clients with your own, custom-rolled logic.

You would then compile your library in the output/myLibrary folder with mvn package and execute the codegen like such:

java -cp output/myLibrary/target/myClientCodegen-swagger-codegen-1.0.0.jar:modules/swagger-codegen-cli/target/swagger-codegen-cli.jar io.swagger.codegen.SwaggerCodegen

For Windows users, you will need to use ; instead of : in the classpath, e.g.:

java -cp output/myLibrary/target/myClientCodegen-swagger-codegen-1.0.0.jar;modules/swagger-codegen-cli/target/swagger-codegen-cli.jar io.swagger.codegen.SwaggerCodegen

Note the myClientCodegen is an option now, and you can use the usual arguments for generating your library:

java -cp output/myLibrary/target/myClientCodegen-swagger-codegen-1.0.0.jar:modules/swagger-codegen-cli/target/swagger-codegen-cli.jar \
  io.swagger.codegen.SwaggerCodegen generate -l myClientCodegen\
  -i https://petstore.swagger.io/v2/swagger.json \
  -o myClient

See also standalone generator development.

Generating a client from local files

If you don’t want to call your server, you can save the OpenAPI Spec files into a directory and pass an argument to the code generator like this:

-i ./modules/swagger-codegen/src/test/resources/2_0/petstore.json

Great for creating libraries on your ci server, from the Swagger Editor… or while coding on an airplane ✈️.

Ignore file format

Swagger Codegen supports a .swagger-codegen-ignore file, similar to .gitignore or .dockerignore you’re probably already familiar with.

The ignore file allows for better control over overwriting existing files than the --skip-overwrite flag. With the ignore file, you can specify individual files or directories can be ignored. This can be useful, for example if you only want a subset of the generated code.

Examples:

# Swagger Codegen Ignore
# Lines beginning with a # are comments

# This should match build.sh located anywhere.
build.sh

# Matches build.sh in the root
/build.sh

# Exclude all recursively
docs/**

# Explicitly allow files excluded by other rules
!docs/UserApi.md

# Recursively exclude directories named Api
# You can't negate files below this directory.
src/**/Api/

# When this file is nested under /Api (excluded above),
# this rule is ignored because parent directory is excluded by previous rule.
!src/**/PetApiTests.cs

# Exclude a single, nested file explicitly
src/IO.Swagger.Test/Model/AnimalFarmTests.cs

The .swagger-codegen-ignore file must exist in the root of the output directory.

Upon first code generation, you may also pass the CLI option --ignore-file-override=/path/to/ignore_file for greater control over generated outputs. Note that this is a complete override, and will override the .swagger-codegen-ignore file in an output directory when regenerating code.

Editor support for .swagger-codegen-ignore files is available in IntelliJ via the .ignore plugin.