OpenAPITools/openapi-generator · error · IllegalArgumentException

clientRegistrationId requires useSpringBoot4=true because @C

Error message

clientRegistrationId requires useSpringBoot4=true because @ClientRegistrationId is provided by Spring Security 7

What it means

Thrown by the Spring generator's option processing when clientRegistrationId is set but useSpringBoot4 is not enabled. The generated HTTP-interface client code relies on @ClientRegistrationId, an annotation introduced with Spring Security 7, which ships only with Spring Boot 4. The generator refuses to emit code that would not compile against older Spring Boot versions.

Source

Thrown at modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/SpringCodegen.java:653

        convertPropertyToBooleanAndWriteBack(USE_SPRING_SECURITY_PRE_AUTHORIZE, this::setUseSpringSecurityPreAuthorize);
        convertPropertyToStringAndWriteBack(SPRING_SECURITY_AUTHORITY_PREFIX, this::setSpringSecurityAuthorityPrefix);

        additionalProperties.put("springHttpStatus", new SpringHttpStatusLambda());

        convertPropertyToBooleanAndWriteBack(USE_ENUM_CASE_INSENSITIVE, this::setUseEnumCaseInsensitive);
        convertPropertyToBooleanAndWriteBack(USE_JACKSON_3, this::setUseJackson3);
        convertPropertyToBooleanAndWriteBack(USE_SPRING_BOOT3, this::setUseSpringBoot3);
        convertPropertyToBooleanAndWriteBack(USE_SPRING_BOOT4, this::setUseSpringBoot4);

        if (isUseSpringBoot4()) {
            setUseSpringBoot3(false);
        }
        if (isNotEmpty(clientRegistrationId)) {
            if (!SPRING_HTTP_INTERFACE.equals(library)) {
                throw new IllegalArgumentException(CLIENT_REGISTRATION_ID + " is only supported with the " + SPRING_HTTP_INTERFACE + " library");
            }
            if (!isUseSpringBoot4()) {
                throw new IllegalArgumentException(CLIENT_REGISTRATION_ID + " requires " + USE_SPRING_BOOT4 + "=true because @ClientRegistrationId is provided by Spring Security 7");
            }
        }
        if (useSpringSecurityPreAuthorize && !SPRING_BOOT.equals(library)) {
            throw new IllegalArgumentException(USE_SPRING_SECURITY_PRE_AUTHORIZE
                    + " is only supported with the " + SPRING_BOOT + " library");
        }

        if (isUseSpringBoot3() || isUseSpringBoot4()) {
            if (AnnotationLibrary.SWAGGER1.equals(getAnnotationLibrary())) {
                throw new IllegalArgumentException(AnnotationLibrary.SWAGGER1.getPropertyName() + " is not supported with Spring Boot > 3.x");
            }
            useJakartaEe = true;
            applyJakartaPackage();
        }
        if(isUseJackson3() && !isUseSpringBoot4()){
            throw new IllegalArgumentException("useJackson3 is only available with Spring Boot >= 4");
        }
        if(this.useJackson3){

View on GitHub (pinned to fcec517be3)

Solutions

Add -DuseSpringBoot4=true (or <useSpringBoot4>true</useSpringBoot4> in the Maven/Gradle plugin config) whenever clientRegistrationId is set.
Keep --library=spring-http-interface; clientRegistrationId is rejected by every other library.
If you must stay on Spring Boot 3, remove clientRegistrationId and register the OAuth2 ClientRegistration in your own Spring configuration.

Example fix

# before
openapi-generator generate -g spring -i api.yaml --library=spring-http-interface -DclientRegistrationId=okta

# after
openapi-generator generate -g spring -i api.yaml --library=spring-http-interface -DclientRegistrationId=okta -DuseSpringBoot4=true

Defensive patterns

Strategy: validation

Validate before calling

# bash: assert option pairing before invoking the generator
if [ -n "$CLIENT_REGISTRATION_ID" ] && [ "$USE_SPRING_BOOT4" != "true" ]; then
  echo "clientRegistrationId requires useSpringBoot4=true" >&2; exit 1
fi
openapi-generator generate -g spring --library=spring-http-interface \
  -DclientRegistrationId=$CLIENT_REGISTRATION_ID -DuseSpringBoot4=$USE_SPRING_BOOT4

Try / catch

// Java (programmatic use)
try {
    opts.put("clientRegistrationId", "okta");
    opts.put("useSpringBoot4", true);
    new DefaultGenerator().opts(clientOptInput).generate();
} catch (IllegalArgumentException e) {
    // option-conflict messages from processOpts(); log and fix config, do not retry
    throw new GenerationConfigException("Invalid spring options: " + e.getMessage(), e);
}

Prevention

Keep one versioned, reviewed generator options file per project instead of ad-hoc CLI flags.
Treat clientRegistrationId as a Boot-4-only feature and document it next to the option.
Fail fast in CI: run generation on every spec change so option conflicts surface immediately.

When it happens

Trigger: Run openapi-generator (CLI, Maven or Gradle plugin) with -g spring, --library=spring-http-interface and -DclientRegistrationId=<id> but without -DuseSpringBoot4=true. This specific message appears only after the library check passed, i.e. library is spring-http-interface.

Common situations: Copying an OAuth2 client example that predates Spring Boot 4 support; enabling clientRegistrationId while keeping Boot 3 defaults; setting useSpringBoot3=true together with clientRegistrationId (the generator silently clears useSpringBoot3 when useSpringBoot4 is on, but not the reverse).

Related errors

AI-assisted analysis of OpenAPITools/openapi-generator@fcec517be3 (2026-08-22). Data as JSON: /api/errors/4c6ce7906da0ff17. Report an issue: GitHub.