OpenAPI client generator incorrectly using response wrapper classes instead of schema classes

[gunnarpruefer]

Tell us the extension you're using

Client

I tried this:

summary:
The OpenAPI generator incorrectly uses response wrapper classes (e.g., CreateFruit201Response) instead of actual schema classes (e.g., Fruit) when resolving $ref references in component schemas.

in detail:
I recreated the issue at https://github.com/gunnarpruefer/openapi-client-generator-schema-reference-bug
which is a newly created Quarkus application (3.30.6) sticking to the known Fruits example and using two relevant dependencies only:

• quarkus-openapi-generator
• quarkus-rest-client-jackson
  Using all the default settings, application.properties is basically empty.

I provided a custom OpenAPI spec, having just 2 operations (a paged GET and a POST).

The generator creates response wrapper classes for operation responses:

• createFruit (201) → CreateFruit201Response
• getFruits (200) → FruitPagedResult which incorrectly uses CreateFruit201Response for _list / the items

When processing component schemas like FruitPagedResult.list's items which references #/components/schemas/Fruit, the generator incorrectly resolves it to CreateFruit201Response instead of Fruit.

This happened:

FruitPagedResult having

private List _list = ...

I expected this:

FruitPagedResult having

private List _list = ...

Is there a workaround?

not that I am aware - the issue also exists with quarkus-rest-client-reactive-jackson

How can we try to reproduce the issue?

I recreated the issue at https://github.com/gunnarpruefer/openapi-client-generator-schema-reference-bug
./mvnw compile and inspect the FruitPagedResult from the model package under target.

Anything else?

the demo app has just been created using the latest https://code.quarkus.io/?a=openapi-client-generator-schema-reference-bug&e=io.quarkiverse.openapi.generator%3Aquarkus-openapi-generator&extension-search=openapi

the sample OpenAPI is correct to the best of my knowledge, but correct me if I am wrong.

Output of uname -a or ver

No response

Output of java -version

openjdk version "25" 2025-09-16 OpenJDK Runtime Environment GraalVM CE 25+37.1 (build 25+37-jvmci-b01) OpenJDK 64-Bit Server VM GraalVM CE 25+37.1 (build 25+37-jvmci-b01, mixed mode, sharing)

Quarkus OpenApi version or git rev

3.30.6, OpenAPI version 3.1.0, for quarkus-rest-client-reactive-jackson 3.15.7

Build tool (ie. output of mvnw --version or gradlew --version)

wrapperVersion=3.3.4 distributionType=only-script distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.12/apache-maven-3.9.12-bin.zip

Additional information

No response

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[gunnarpruefer]

Seems there is an issue with the actual and the expectations, here we go:

This happened:
FruitPagedResult having
private List< CreateFruit201Response > _list = ...

I expected this:
FruitPagedResult having
private List< Fruit > _list = ...

[mcruzdev]

Thanks for reporting this issue and by the clear reproducer, I tried here and really this behavior is weird. ASAP I will investigate it.

[github-actions]

@quarkiverse/quarkiverse-openapi-generator This is being labeled as Stale.

[github-actions]

@quarkiverse/quarkiverse-openapi-generator This is being closed due to inactivity.