diff --git a/client/deployment/pom.xml b/client/deployment/pom.xml
index 68c37256..5fb3f85c 100644
--- a/client/deployment/pom.xml
+++ b/client/deployment/pom.xml
@@ -169,9 +169,6 @@
                   <version>${quarkus.version}</version>
                 </path>
               </annotationProcessorPaths>
-              <compilerArgs>
-                <arg>-AlegacyConfigRoot=true</arg>
-              </compilerArgs>
             </configuration>
           </execution>
         </executions>
diff --git a/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/CodegenConfig.java b/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/CodegenConfig.java
index 02192c6a..883a6cf9 100644
--- a/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/CodegenConfig.java
+++ b/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/CodegenConfig.java
@@ -7,30 +7,32 @@
 import java.util.stream.Collectors;
 
 import io.quarkiverse.openapi.generator.deployment.codegen.OpenApiGeneratorOutputPaths;
-import io.quarkus.runtime.annotations.ConfigItem;
 import io.quarkus.runtime.annotations.ConfigPhase;
 import io.quarkus.runtime.annotations.ConfigRoot;
+import io.smallrye.config.ConfigMapping;
+import io.smallrye.config.WithName;
 import io.smallrye.config.common.utils.StringUtil;
 
 // This configuration is read in codegen phase (before build time), the annotation is for document purposes and avoiding quarkus warns
-@ConfigRoot(name = CodegenConfig.CODEGEN_TIME_CONFIG_PREFIX, phase = ConfigPhase.BUILD_TIME)
-public class CodegenConfig extends GlobalCodegenConfig {
+@ConfigRoot(phase = ConfigPhase.BUILD_TIME)
+@ConfigMapping(prefix = "quarkus." + CodegenConfig.CODEGEN_TIME_CONFIG_PREFIX)
+public interface CodegenConfig extends GlobalCodegenConfig {
 
-    static final String CODEGEN_TIME_CONFIG_PREFIX = "openapi-generator.codegen";
+    String CODEGEN_TIME_CONFIG_PREFIX = "openapi-generator.codegen";
 
-    public static final String API_PKG_SUFFIX = ".api";
-    public static final String MODEL_PKG_SUFFIX = ".model";
+    String API_PKG_SUFFIX = ".api";
+    String MODEL_PKG_SUFFIX = ".model";
 
-    public static final String ADDITIONAL_ENUM_TYPE_UNEXPECTED_MEMBER_NAME_DEFAULT = "UNEXPECTED";
-    public static final String ADDITIONAL_ENUM_TYPE_UNEXPECTED_MEMBER_STRING_VALUE_DEFAULT = "unexpected";
+    String ADDITIONAL_ENUM_TYPE_UNEXPECTED_MEMBER_NAME_DEFAULT = "UNEXPECTED";
+    String ADDITIONAL_ENUM_TYPE_UNEXPECTED_MEMBER_STRING_VALUE_DEFAULT = "unexpected";
     // package visibility for unit tests
-    static final String BUILD_TIME_GLOBAL_PREFIX_FORMAT = "quarkus." + CODEGEN_TIME_CONFIG_PREFIX + ".%s";
-    static final String BUILD_TIME_SPEC_PREFIX_FORMAT = "quarkus." + CODEGEN_TIME_CONFIG_PREFIX + ".spec.%s";
+    String BUILD_TIME_GLOBAL_PREFIX_FORMAT = "quarkus." + CODEGEN_TIME_CONFIG_PREFIX + ".%s";
+    String BUILD_TIME_SPEC_PREFIX_FORMAT = "quarkus." + CODEGEN_TIME_CONFIG_PREFIX + ".spec.%s";
 
-    public static final List<String> SUPPORTED_CONFIGURATIONS = Arrays.stream(ConfigName.values()).map(cn -> cn.name)
+    List<String> SUPPORTED_CONFIGURATIONS = Arrays.stream(ConfigName.values()).map(cn -> cn.name)
             .collect(Collectors.toList());
 
-    public enum ConfigName {
+    enum ConfigName {
         //global configs
         VERBOSE("verbose"),
         INPUT_BASE_DIR("input-base-dir"),
@@ -88,28 +90,28 @@ public enum ConfigName {
     /**
      * OpenAPI Spec details for codegen configuration.
      */
-    @ConfigItem(name = "spec")
-    public Map<String, SpecItemConfig> specItem;
+    @WithName("spec")
+    Map<String, SpecItemConfig> specItem();
 
-    public static String resolveApiPackage(final String basePackage) {
+    static String resolveApiPackage(final String basePackage) {
         return String.format("%s%s", basePackage, API_PKG_SUFFIX);
     }
 
-    public static String resolveModelPackage(final String basePackage) {
+    static String resolveModelPackage(final String basePackage) {
         return String.format("%s%s", basePackage, MODEL_PKG_SUFFIX);
     }
 
     /**
      * Return global config name, openapi-generator.codegen.config-name
      */
-    public static String getGlobalConfigName(ConfigName configName) {
+    static String getGlobalConfigName(ConfigName configName) {
         return String.format(BUILD_TIME_GLOBAL_PREFIX_FORMAT, configName.name);
     }
 
     /**
      * Return spec config name openapi-generator.codegen.spec.%s.config-name
      */
-    public static String getSpecConfigName(ConfigName configName, final Path openApiFilePath) {
+    static String getSpecConfigName(ConfigName configName, final Path openApiFilePath) {
         return String.format("%s.%s", getBuildTimeSpecPropertyPrefix(openApiFilePath), configName.name);
     }
 
@@ -119,7 +121,7 @@ public static String getSpecConfigName(ConfigName configName, final Path openApi
      * returned value is
      * <code>openapi.generator.codegen.spec.petstore.mutiny</code>.
      */
-    public static String getSpecConfigNameByConfigKey(final String configKey, final ConfigName configName) {
+    static String getSpecConfigNameByConfigKey(final String configKey, final ConfigName configName) {
         String buildTimeSpecPropertyPrefix = String.format(BUILD_TIME_SPEC_PREFIX_FORMAT, configKey);
         return String.format("%s.%s", buildTimeSpecPropertyPrefix, configName.name);
     }
@@ -130,11 +132,11 @@ public static String getSpecConfigNameByConfigKey(final String configKey, final
      * `quarkus.openapi-generator."petstore_json"`.
      * Every the periods (.) in the file name will be replaced by underscore (_).
      */
-    public static String getBuildTimeSpecPropertyPrefix(final Path openApiFilePath) {
+    static String getBuildTimeSpecPropertyPrefix(final Path openApiFilePath) {
         return String.format(BUILD_TIME_SPEC_PREFIX_FORMAT, getSanitizedFileName(openApiFilePath));
     }
 
-    public static String getSanitizedFileName(final Path openApiFilePath) {
+    static String getSanitizedFileName(final Path openApiFilePath) {
         return StringUtil
                 .replaceNonAlphanumericByUnderscores(OpenApiGeneratorOutputPaths.getRelativePath(openApiFilePath).toString());
     }
diff --git a/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/CommonItemConfig.java b/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/CommonItemConfig.java
index 6d65cf4b..487403b5 100644
--- a/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/CommonItemConfig.java
+++ b/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/CommonItemConfig.java
@@ -3,8 +3,7 @@
 import java.util.Map;
 import java.util.Optional;
 
-import io.quarkus.runtime.annotations.ConfigGroup;
-import io.quarkus.runtime.annotations.ConfigItem;
+import io.smallrye.config.WithName;
 
 /*
  * Model for the configuration of this extension.
@@ -13,92 +12,91 @@
  * Not meant to be used outside this scope.
  * Config items can be applied on spec and globally as well
  */
-@ConfigGroup
-public class CommonItemConfig {
+public interface CommonItemConfig {
 
     /**
      * Whether to skip the generation of models for form parameters
      */
-    @ConfigItem(name = "skip-form-model")
-    public Optional<Boolean> skipFormModel;
+    @WithName("skip-form-model")
+    Optional<Boolean> skipFormModel();
 
     /**
      * Type Mapping is an OpenAPI Generator configuration specifying which Java types (the values) should be used for a
      * given OAS datatype (the keys of this map)
      */
-    @ConfigItem(name = "type-mappings")
-    public Map<String, String> typeMappings;
+    @WithName("type-mappings")
+    Map<String, String> typeMappings();
 
     /**
      * Import Mapping is an OpenAPI Generator configuration specifying which Java types (the values) should be
      * imported when a given OAS datatype (the keys of this map) is used
      */
-    @ConfigItem(name = "import-mappings")
-    public Map<String, String> importMappings;
+    @WithName("import-mappings")
+    Map<String, String> importMappings();
 
     /**
      * Schema Mapping is an OpenAPI Generator configuration specifying which Java types (the values) should be
      * imported when a given schema type (the keys of this map) is used
      */
-    @ConfigItem(name = "schema-mappings")
-    public Map<String, String> schemaMappings;
+    @WithName("schema-mappings")
+    Map<String, String> schemaMappings();
 
     /**
      * The specified annotations will be added to the generated model files
      */
-    @ConfigItem(name = "additional-model-type-annotations")
-    public Optional<String> additionalModelTypeAnnotations;
+    @WithName("additional-model-type-annotations")
+    Optional<String> additionalModelTypeAnnotations();
 
     /**
      * Defines if the enums should have an `UNEXPECTED` member to convey values that cannot be parsed. Default is
      * {@code false}.
      */
-    @ConfigItem(name = "additional-enum-type-unexpected-member")
-    public Optional<Boolean> additionalEnumTypeUnexpectedMemberAnnotations;
+    @WithName("additional-enum-type-unexpected-member")
+    Optional<Boolean> additionalEnumTypeUnexpectedMemberAnnotations();
 
     /**
      * The specified annotations will be added to the generated api files
      */
-    @ConfigItem(name = "additional-api-type-annotations")
-    public Optional<String> additionalApiTypeAnnotations;
+    @WithName("additional-api-type-annotations")
+    Optional<String> additionalApiTypeAnnotations();
 
     /**
      * Add custom/additional HTTP Headers or other args to every request
      */
-    @ConfigItem(name = "additional-request-args")
-    public Optional<String> additionalRequestArgs;
+    @WithName("additional-request-args")
+    Optional<String> additionalRequestArgs();
 
     /**
      * Defines if the methods should return {@link jakarta.ws.rs.core.Response} or a model. Default is {@code false}.
      */
-    @ConfigItem(name = "return-response")
-    public Optional<Boolean> returnResponse;
+    @WithName("return-response")
+    Optional<Boolean> returnResponse();
 
     /**
      * Defines if security support classes should be generated
      */
-    @ConfigItem(name = "enable-security-generation")
-    public Optional<String> enableSecurityGeneration;
+    @WithName("enable-security-generation")
+    Optional<String> enableSecurityGeneration();
 
     /**
      * Defines the normalizer options.
      */
-    @ConfigItem(name = "open-api-normalizer")
-    public Map<String, String> normalizer;
+    @WithName("open-api-normalizer")
+    Map<String, String> normalizer();
 
     /**
      * Enable SmallRye Mutiny support. If you set this to {@code true}, all return types will be wrapped in
      * {@link io.smallrye.mutiny.Uni}.
      */
-    @ConfigItem(name = "mutiny")
-    public Optional<Boolean> supportMutiny;
+    @WithName("mutiny")
+    Optional<Boolean> supportMutiny();
 
     /**
      * Defines with SmallRye Mutiny enabled if methods should return {@link jakarta.ws.rs.core.Response} or a model. Default is
      * {@code false}.
      */
-    @ConfigItem(name = "mutiny.return-response")
-    public Optional<Boolean> mutinyReturnResponse;
+    @WithName("mutiny.return-response")
+    Optional<Boolean> mutinyReturnResponse();
 
     /**
      * Handles the return type for each operation, depending on the configuration.
@@ -125,16 +123,16 @@ public class CommonItemConfig {
      * - If the operation has a void return type, it will return {@link io.smallrye.mutiny.Uni<jakarta.ws.rs.core.Response>}.
      * - Otherwise, it will return {@link io.smallrye.mutiny.Uni<returnType>}`.
      */
-    @ConfigItem(name = "mutiny.operation-ids")
-    public Optional<Map<String, String>> mutinyMultiOperationIds;
+    @WithName("mutiny.operation-ids")
+    Map<String, String> mutinyMultiOperationIds();
 
     /**
      * Defines, whether the `PartFilename` ({@link org.jboss.resteasy.reactive.PartFilename} or
      * {@link org.jboss.resteasy.annotations.providers.multipart.PartFilename}) annotation should be generated for
      * MultipartForm POJOs. By setting to {@code false}, the annotation will not be generated.
      */
-    @ConfigItem(name = "generate-part-filename")
-    public Optional<Boolean> generatePartFilename;
+    @WithName("generate-part-filename")
+    Optional<Boolean> generatePartFilename();
 
     /**
      * Defines the filename for a part in case the `PartFilename` annotation
@@ -143,40 +141,40 @@ public class CommonItemConfig {
      * In case no value is set, the default one is `&lt;fieldName&gt;File` or `file`, depending on the
      * {@link CommonItemConfig#useFieldNameInPartFilename} configuration.
      */
-    @ConfigItem(name = "part-filename-value")
-    public Optional<String> partFilenameValue;
+    @WithName("part-filename-value")
+    Optional<String> partFilenameValue();
 
     /**
      * Defines, whether the filename should also include the property name in case the `PartFilename` annotation
      * ({@link org.jboss.resteasy.reactive.PartFilename} or
      * {@link org.jboss.resteasy.annotations.providers.multipart.PartFilename}) is generated.
      */
-    @ConfigItem(name = "use-field-name-in-part-filename")
-    public Optional<Boolean> useFieldNameInPartFilename;
+    @WithName("use-field-name-in-part-filename")
+    Optional<Boolean> useFieldNameInPartFilename();
 
     /**
      * Enable bean validation. If you set this to {@code true}, validation annotations are added to generated sources E.g.
      * {@code @Size}.
      */
-    @ConfigItem(name = "use-bean-validation")
-    public Optional<Boolean> useBeanValidation;
+    @WithName("use-bean-validation")
+    Optional<Boolean> useBeanValidation();
 
     /**
      * Enable the generation of APIs. If you set this to {@code false}, APIs will not be generated.
      */
-    @ConfigItem(name = "generate-apis")
-    public Optional<Boolean> generateApis;
+    @WithName("generate-apis")
+    Optional<Boolean> generateApis();
 
     /**
      * Enable the generation of models. If you set this to {@code false}, models will not be generated.
      */
-    @ConfigItem(name = "generate-models")
-    public Optional<Boolean> generateModels;
+    @WithName("generate-models")
+    Optional<Boolean> generateModels();
 
     /**
      * Enable the generation of equals and hashcode in models. If you set this to {@code false}, the models
      * will not have equals and hashcode.
      */
-    @ConfigItem(name = "equals-hashcode")
-    public Optional<Boolean> equalsHashcode;
+    @WithName("equals-hashcode")
+    Optional<Boolean> equalsHashcode();
 }
diff --git a/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/GlobalCodegenConfig.java b/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/GlobalCodegenConfig.java
index aff927be..0c9f5888 100644
--- a/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/GlobalCodegenConfig.java
+++ b/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/GlobalCodegenConfig.java
@@ -2,8 +2,8 @@
 
 import java.util.Optional;
 
-import io.quarkus.runtime.annotations.ConfigGroup;
-import io.quarkus.runtime.annotations.ConfigItem;
+import io.smallrye.config.WithDefault;
+import io.smallrye.config.WithName;
 
 /*
  * Model for the configuration of this extension.
@@ -12,50 +12,51 @@
  * Not meant to be used outside this scope.
  * Config items can be applied only globally
  */
-@ConfigGroup
-public class GlobalCodegenConfig extends CommonItemConfig {
+public interface GlobalCodegenConfig extends CommonItemConfig {
 
     /**
      * Whether to log the internal generator codegen process in the default output or not.
      */
-    @ConfigItem(name = "verbose", defaultValue = "false")
-    public boolean verbose;
+    @WithDefault("false")
+    @WithName("verbose")
+    boolean verbose();
 
     /**
      * Option to change the directory where OpenAPI files must be found.
      */
-    @ConfigItem(name = "input-base-dir")
-    public Optional<String> inputBaseDir;
+    @WithName("input-base-dir")
+    Optional<String> inputBaseDir();
 
     /**
      * Option to change the directory where template files must be found.
      */
-    @ConfigItem(name = "template-base-dir")
-    public Optional<String> templateBaseDir;
+    @WithName("template-base-dir")
+    Optional<String> templateBaseDir();
 
     /**
      * Whether or not to skip validating the input spec prior to generation. By default, invalid specifications will result in
      * an error.
      */
-    @ConfigItem(name = "validateSpec", defaultValue = "true")
-    public boolean validateSpec;
+    @WithName("validateSpec")
+    @WithDefault("true")
+    boolean validateSpec();
 
     /**
      * Option to specify files for which generation should be executed only
      */
-    @ConfigItem(name = "include")
-    public Optional<String> include;
+    @WithName("include")
+    Optional<String> include();
 
     /**
      * Option to exclude file from generation
      */
-    @ConfigItem(name = "exclude")
-    public Optional<String> exclude;
+    @WithName("exclude")
+    Optional<String> exclude();
 
     /**
      * Create security for the referenced security scheme
      */
-    @ConfigItem(name = "default-security-scheme")
-    public Optional<String> defaultSecuritySchema;
+    @WithName("default-security-scheme")
+    Optional<String> defaultSecuritySchema();
 
 }
diff --git a/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/SpecItemConfig.java b/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/SpecItemConfig.java
index 3eb45978..bffb801f 100644
--- a/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/SpecItemConfig.java
+++ b/client/deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/SpecItemConfig.java
@@ -2,8 +2,7 @@
 
 import java.util.Optional;
 
-import io.quarkus.runtime.annotations.ConfigGroup;
-import io.quarkus.runtime.annotations.ConfigItem;
+import io.smallrye.config.WithName;
 
 /*
  * Model for the configuration of this extension.
@@ -12,48 +11,48 @@
  * Not meant to be used outside this scope.
  * Config items can be applied only on spec
  */
-@ConfigGroup
-public class SpecItemConfig extends CommonItemConfig {
+public interface SpecItemConfig extends CommonItemConfig {
 
     /**
      * Base package for where the generated code for the given OpenAPI specification will be added.
      */
-    @ConfigItem(name = "base-package")
-    public Optional<String> basePackage;
+    @WithName("base-package")
+    Optional<String> basePackage();
 
     /**
      * Suffix name for generated api classes
      */
-    @ConfigItem(name = "api-name-suffix")
-    public Optional<String> apiNameSuffix;
+    @WithName("api-name-suffix")
+    Optional<String> apiNameSuffix();
 
     /**
      * Suffix name for generated model classes
      */
-    @ConfigItem(name = "model-name-suffix")
-    public Optional<String> modelNameSuffix;
+    @WithName("model-name-suffix")
+    Optional<String> modelNameSuffix();
 
     /**
      * Prefix name for generated model classes
      */
-    @ConfigItem(name = "model-name-prefix")
-    public Optional<String> modelNamePrefix;
+    @WithName("model-name-prefix")
+    Optional<String> modelNamePrefix();
 
     /**
      * Remove operation id prefix
      */
-    @ConfigItem(name = "remove-operation-id-prefix")
-    public Optional<Boolean> removeOperationIdPrefix;
+
+    @WithName("remove-operation-id-prefix")
+    Optional<Boolean> removeOperationIdPrefix();
 
     /**
      * Remove operation id prefix
      */
-    @ConfigItem(name = "remove-operation-id-prefix-delimiter")
-    public Optional<String> removeOperationIdPrefixDelimiter;
+    @WithName("remove-operation-id-prefix-delimiter")
+    Optional<String> removeOperationIdPrefixDelimiter();
 
     /**
      * Remove operation id prefix
      */
-    @ConfigItem(name = "remove-operation-id-prefix-count")
-    public Optional<Integer> removeOperationIdPrefixCount;
+    @WithName("remove-operation-id-prefix-count")
+    Optional<Integer> removeOperationIdPrefixCount();
 }
diff --git a/client/runtime/pom.xml b/client/runtime/pom.xml
index d50c39f2..e5ec29b6 100644
--- a/client/runtime/pom.xml
+++ b/client/runtime/pom.xml
@@ -94,9 +94,6 @@
                   <version>${quarkus.version}</version>
                 </path>
               </annotationProcessorPaths>
-              <compilerArgs>
-                <arg>-AlegacyConfigRoot=true</arg>
-              </compilerArgs>
             </configuration>
           </execution>
         </executions>
diff --git a/client/runtime/src/main/java/io/quarkiverse/openapi/generator/AuthsConfig.java b/client/runtime/src/main/java/io/quarkiverse/openapi/generator/AuthsConfig.java
index a02f00c1..ce90f077 100644
--- a/client/runtime/src/main/java/io/quarkiverse/openapi/generator/AuthsConfig.java
+++ b/client/runtime/src/main/java/io/quarkiverse/openapi/generator/AuthsConfig.java
@@ -3,11 +3,9 @@
 import java.util.Map;
 import java.util.Optional;
 
-import io.quarkus.runtime.annotations.ConfigGroup;
-import io.quarkus.runtime.annotations.ConfigItem;
+import io.smallrye.config.WithParentName;
 
-@ConfigGroup
-public class AuthsConfig {
+public interface AuthsConfig {
 
     /**
      * Configurations for the individual securitySchemes present on a given OpenApi spec definition file.
@@ -21,17 +19,10 @@ public class AuthsConfig {
      * @see SpecItemConfig
      * @see AuthConfig
      */
-    @ConfigItem(name = ConfigItem.PARENT)
-    public Map<String, AuthConfig> authConfigs;
+    @WithParentName()
+    Map<String, AuthConfig> authConfigs();
 
-    public Optional<AuthConfig> getItemConfig(String authConfig) {
-        return Optional.ofNullable(authConfigs.get(authConfig));
-    }
-
-    @Override
-    public String toString() {
-        return "AuthsConfig{" +
-                "authConfigs=" + authConfigs +
-                '}';
+    default Optional<AuthConfig> getItemConfig(String authConfig) {
+        return Optional.ofNullable(authConfigs().get(authConfig));
     }
 }
diff --git a/client/runtime/src/main/java/io/quarkiverse/openapi/generator/OpenApiGeneratorConfig.java b/client/runtime/src/main/java/io/quarkiverse/openapi/generator/OpenApiGeneratorConfig.java
index 6b297f57..9fe301a9 100644
--- a/client/runtime/src/main/java/io/quarkiverse/openapi/generator/OpenApiGeneratorConfig.java
+++ b/client/runtime/src/main/java/io/quarkiverse/openapi/generator/OpenApiGeneratorConfig.java
@@ -3,18 +3,20 @@
 import java.util.Map;
 import java.util.Optional;
 
-import io.quarkus.runtime.annotations.ConfigItem;
 import io.quarkus.runtime.annotations.ConfigPhase;
 import io.quarkus.runtime.annotations.ConfigRoot;
+import io.smallrye.config.ConfigMapping;
+import io.smallrye.config.WithParentName;
 import io.smallrye.config.common.utils.StringUtil;
 
 /**
  * This class represents the runtime configurations for the openapi-generator extension.
  */
-@ConfigRoot(name = OpenApiGeneratorConfig.RUNTIME_TIME_CONFIG_PREFIX, phase = ConfigPhase.RUN_TIME)
-public class OpenApiGeneratorConfig {
+@ConfigMapping(prefix = "quarkus." + OpenApiGeneratorConfig.RUNTIME_TIME_CONFIG_PREFIX)
+@ConfigRoot(phase = ConfigPhase.RUN_TIME)
+public interface OpenApiGeneratorConfig {
 
-    public static final String RUNTIME_TIME_CONFIG_PREFIX = "openapi-generator";
+    String RUNTIME_TIME_CONFIG_PREFIX = "openapi-generator";
 
     /**
      * Configurations of the individual OpenApi spec definitions, i.e. the provided files.
@@ -23,21 +25,14 @@ public class OpenApiGeneratorConfig {
      * For example, a file named petstore.json is sanitized into the name petstore_json, and thus the specific
      * configurations this file must start with the prefix quarkus.openapi-generator.petstore_json
      */
-    @ConfigItem(name = ConfigItem.PARENT)
-    public Map<String, SpecItemConfig> itemConfigs;
+    @WithParentName
+    Map<String, SpecItemConfig> itemConfigs();
 
-    public Optional<SpecItemConfig> getItemConfig(String specItem) {
-        return Optional.ofNullable(itemConfigs.get(specItem));
+    default Optional<SpecItemConfig> getItemConfig(String specItem) {
+        return Optional.ofNullable(itemConfigs().get(specItem));
     }
 
-    @Override
-    public String toString() {
-        return "OpenApiGeneratorConfig{" +
-                "itemConfigs=" + itemConfigs +
-                '}';
-    }
-
-    public static String getSanitizedSecuritySchemeName(final String securitySchemeName) {
+    static String getSanitizedSecuritySchemeName(final String securitySchemeName) {
         return StringUtil.replaceNonAlphanumericByUnderscores(securitySchemeName);
     }
 }
diff --git a/client/runtime/src/main/java/io/quarkiverse/openapi/generator/SpecItemConfig.java b/client/runtime/src/main/java/io/quarkiverse/openapi/generator/SpecItemConfig.java
index 91c79b65..da942e1f 100644
--- a/client/runtime/src/main/java/io/quarkiverse/openapi/generator/SpecItemConfig.java
+++ b/client/runtime/src/main/java/io/quarkiverse/openapi/generator/SpecItemConfig.java
@@ -2,15 +2,11 @@
 
 import java.util.Optional;
 
-import io.quarkus.runtime.annotations.ConfigGroup;
-import io.quarkus.runtime.annotations.ConfigItem;
-
 /**
  * This class represents the runtime authentication related configurations for the individual OpenApi spec definitions,
  * i.e. the provided files.
  */
-@ConfigGroup
-public class SpecItemConfig {
+public interface SpecItemConfig {
 
     /**
      * Authentication related configurations for the different securitySchemes present on a given OpenApi spec
@@ -21,17 +17,9 @@ public class SpecItemConfig {
      *
      * @see AuthsConfig
      */
-    @ConfigItem
-    public AuthsConfig auth;
-
-    public Optional<AuthsConfig> getAuth() {
-        return Optional.ofNullable(auth);
-    }
+    AuthsConfig auth();
 
-    @Override
-    public String toString() {
-        return "SpecItemConfig{" +
-                "auth=" + auth +
-                '}';
+    default Optional<AuthsConfig> getAuth() {
+        return Optional.ofNullable(auth());
     }
-}
\ No newline at end of file
+}
diff --git a/server/deployment/pom.xml b/server/deployment/pom.xml
index 7c961912..2358b448 100755
--- a/server/deployment/pom.xml
+++ b/server/deployment/pom.xml
@@ -38,9 +38,6 @@
                                     <version>${quarkus.version}</version>
                                 </path>
                             </annotationProcessorPaths>
-                            <compilerArgs>
-                                <arg>-AlegacyConfigRoot=true</arg>
-                            </compilerArgs>
                         </configuration>
                     </execution>
                 </executions>
diff --git a/server/deployment/src/main/java/io/quarkiverse/openapi/server/generator/deployment/CodegenConfig.java b/server/deployment/src/main/java/io/quarkiverse/openapi/server/generator/deployment/CodegenConfig.java
index 139c2c1f..19f5d9a5 100755
--- a/server/deployment/src/main/java/io/quarkiverse/openapi/server/generator/deployment/CodegenConfig.java
+++ b/server/deployment/src/main/java/io/quarkiverse/openapi/server/generator/deployment/CodegenConfig.java
@@ -2,29 +2,31 @@
 
 import io.quarkus.runtime.annotations.ConfigPhase;
 import io.quarkus.runtime.annotations.ConfigRoot;
+import io.smallrye.config.ConfigMapping;
 
-@ConfigRoot(name = CodegenConfig.CODEGEN_TIME_CONFIG_PREFIX, phase = ConfigPhase.BUILD_TIME)
-public class CodegenConfig {
+@ConfigRoot(phase = ConfigPhase.BUILD_TIME)
+@ConfigMapping(prefix = CodegenConfig.CODEGEN_TIME_CONFIG_PREFIX)
+public interface CodegenConfig {
 
-    static final String CODEGEN_TIME_CONFIG_PREFIX = "quarkus.openapi.generator";
-    private static final String CODEGEN_BASE_PACKAGE = CODEGEN_TIME_CONFIG_PREFIX + ".base-package";
-    private static final String CODEGEN_SPEC = CODEGEN_TIME_CONFIG_PREFIX + ".spec";
-    private static final String INPUT_BASE_DIR = CODEGEN_TIME_CONFIG_PREFIX + ".input-base-dir";
-    private static final String CODEGEN_REACTIVE = CODEGEN_TIME_CONFIG_PREFIX + ".reactive";
+    String CODEGEN_TIME_CONFIG_PREFIX = "quarkus.openapi.generator";
+    String CODEGEN_BASE_PACKAGE = CODEGEN_TIME_CONFIG_PREFIX + ".base-package";
+    String CODEGEN_SPEC = CODEGEN_TIME_CONFIG_PREFIX + ".spec";
+    String INPUT_BASE_DIR = CODEGEN_TIME_CONFIG_PREFIX + ".input-base-dir";
+    String CODEGEN_REACTIVE = CODEGEN_TIME_CONFIG_PREFIX + ".reactive";
 
-    public static String getBasePackagePropertyName() {
+    static String getBasePackagePropertyName() {
         return CODEGEN_BASE_PACKAGE;
     }
 
-    public static String getSpecPropertyName() {
+    static String getSpecPropertyName() {
         return CODEGEN_SPEC;
     }
 
-    public static String getInputBaseDirPropertyName() {
+    static String getInputBaseDirPropertyName() {
         return INPUT_BASE_DIR;
     }
 
-    public static String getCodegenReactive() {
+    static String getCodegenReactive() {
         return CODEGEN_REACTIVE;
     }
 }