diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/back-compatible.tsp b/specification/appcomplianceautomation/AppComplianceAutomation.Management/back-compatible.tsp
new file mode 100644
index 000000000000..02174c5a5d77
--- /dev/null
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/back-compatible.tsp
@@ -0,0 +1,25 @@
+import "@azure-tools/typespec-client-generator-core";
+
+using Azure.ClientGenerator.Core;
+using Microsoft.AppComplianceAutomation;
+
+#suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
+@@Azure.ClientGenerator.Core.Legacy.flattenProperty(EvidenceResource.properties,
+  "autorest,go,python,javascript"
+);
+#suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
+@@Azure.ClientGenerator.Core.Legacy.flattenProperty(ReportResource.properties,
+  "autorest,go,python,javascript"
+);
+#suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
+@@Azure.ClientGenerator.Core.Legacy.flattenProperty(ScopingConfigurationResource.properties,
+  "autorest,go,python,javascript"
+);
+#suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
+@@Azure.ClientGenerator.Core.Legacy.flattenProperty(SnapshotResource.properties,
+  "autorest,go,python,javascript"
+);
+#suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
+@@Azure.ClientGenerator.Core.Legacy.flattenProperty(WebhookResource.properties,
+  "autorest,go,python,javascript"
+);
diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/client.tsp b/specification/appcomplianceautomation/AppComplianceAutomation.Management/client.tsp
index 745941d727e8..6bd4387d9804 100644
--- a/specification/appcomplianceautomation/AppComplianceAutomation.Management/client.tsp
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/client.tsp
@@ -2,8 +2,225 @@ import "./main.tsp";
 import "@azure-tools/typespec-client-generator-core";
 
 using Azure.ClientGenerator.Core;
+using Azure.Core;
+using Azure.ResourceManager.Foundations;
+using Microsoft.AppComplianceAutomation;
 
 @@clientName(Microsoft.AppComplianceAutomation,
   "AppComplianceAutomationMgmt",
   "python"
 );
+
+@@alternateType(Azure.ResourceManager.CommonTypes.Resource.id,
+  armResourceIdentifier,
+  "csharp"
+);
+@@clientName(EvidenceResource, "AppComplianceReportEvidence", "csharp");
+@@clientName(EvidenceProperties,
+  "AppComplianceReportEvidenceProperties",
+  "csharp"
+);
+@@clientName(ReportResource, "AppComplianceReport", "csharp");
+@@clientName(ScopingConfigurationResource,
+  "AppComplianceReportScopingConfiguration",
+  "csharp"
+);
+@@clientName(ScopingConfigurationProperties,
+  "AppComplianceReportScopingConfigurationProperties",
+  "csharp"
+);
+@@usage(SnapshotResource, Usage.input | Usage.output, "csharp");
+@@clientName(SnapshotResource, "AppComplianceReportSnapshot", "csharp");
+@@clientName(SnapshotProperties,
+  "AppComplianceReportSnapshotProperties",
+  "csharp"
+);
+@@clientName(WebhookResource, "AppComplianceReportWebhook", "csharp");
+@@clientName(WebhookProperties,
+  "AppComplianceReportWebhookProperties",
+  "csharp"
+);
+@@alternateType(WebhookProperties.payloadUrl, url, "csharp");
+@@alternateType(WebhookProperties.tenantId, uuid, "csharp");
+@@clientName(SendAllEvents, "SendAllEvent", "csharp");
+@@clientName(Category, "AppComplianceCategory", "csharp");
+@@clientName(CategoryStatus, "AppComplianceCategoryStatus", "csharp");
+@@clientName(ProviderActions.checkNameAvailability,
+  "CheckAppComplianceReportNameAvailability",
+  "csharp"
+);
+@@clientName(Report.checkNameAvailability,
+  "CheckAppComplianceReportNestedResourceNameAvailability",
+  "csharp"
+);
+@@clientName(CheckNameAvailabilityReason,
+  "AppComplianceReportNameUnavailabilityReason",
+  "csharp"
+);
+@@clientName(CheckNameAvailabilityRequest,
+  "AppComplianceReportNameAvailabilityContent",
+  "csharp"
+);
+@@clientName(CheckNameAvailabilityRequest.type, "ResourceType", "csharp");
+@@clientName(CheckNameAvailabilityResponse,
+  "AppComplianceReportNameAvailabilityResult",
+  "csharp"
+);
+@@clientName(CheckNameAvailabilityResponse.nameAvailable,
+  "IsNameAvailable",
+  "csharp"
+);
+@@alternateType(CheckNameAvailabilityRequest.type, armResourceType, "csharp");
+@@clientName(ComplianceReportItem, "AppComplianceReportItem", "csharp");
+@@alternateType(ComplianceReportItem.resourceId,
+  armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(ComplianceReportItem.resourceType, armResourceType, "csharp");
+@@clientName(ComplianceReportItem.resourceStatusChangeDate,
+  "ResourceStatusChangedOn",
+  "csharp"
+);
+@@clientName(ComplianceResult, "AppComplianceResult", "csharp");
+@@clientName(ContentType, "WebhookContentType", "csharp");
+@@clientName(Control, "AppComplianceControl", "csharp");
+@@alternateType(Control.controlDescriptionHyperLink, url, "csharp");
+@@clientName(ControlFamily, "AppComplianceControlFamily", "csharp");
+@@clientName(ControlStatus, "AppComplianceControlStatus", "csharp");
+@@clientName(DeliveryStatus, "WebhookDeliveryStatus", "csharp");
+@@clientName(DownloadResponse, "AppComplianceDownloadResult", "csharp");
+@@clientName(DownloadResponseComplianceDetailedPdfReport,
+  "AppComplianceDetailedPdfReport",
+  "csharp"
+);
+@@alternateType(DownloadResponseComplianceDetailedPdfReport.sasUri,
+  url,
+  "csharp"
+);
+@@clientName(DownloadResponseCompliancePdfReport,
+  "AppCompliancePdfReport",
+  "csharp"
+);
+@@alternateType(DownloadResponseCompliancePdfReport.sasUri, url, "csharp");
+@@clientName(DownloadType, "AppComplianceDownloadType", "csharp");
+@@clientName(EvidenceFileDownloadResponse,
+  "EvidenceFileDownloadResult",
+  "csharp"
+);
+@@clientName(EvidenceFileDownloadResponseEvidenceFile,
+  "EvidenceFileUrlInfo",
+  "csharp"
+);
+@@alternateType(EvidenceFileDownloadResponseEvidenceFile.url, url, "csharp");
+@@clientName(EvidenceType, "AppComplianceReportEvidenceType", "csharp");
+@@clientName(GetCollectionCountRequest,
+  "ReportCollectionGetCountContent",
+  "csharp"
+);
+@@clientName(GetCollectionCountRequest.type,
+  "GetCollectionCountRequestType",
+  "csharp"
+);
+@@clientName(GetCollectionCountResponse,
+  "ReportCollectionGetCountResult",
+  "csharp"
+);
+@@clientName(GetOverviewStatusRequest,
+  "AppComplianceGetOverviewStatusContent",
+  "csharp"
+);
+@@clientName(GetOverviewStatusRequest.type,
+  "GetOverviewStatusRequestType",
+  "csharp"
+);
+@@clientName(GetOverviewStatusResponse,
+  "AppComplianceGetOverviewStatusResult",
+  "csharp"
+);
+@@clientName(InputType, "ScopingQuestionInputType", "csharp");
+@@clientName(ListInUseStorageAccountsRequest,
+  "ReportListInUseStorageAccountsContent",
+  "csharp"
+);
+@@clientName(ListInUseStorageAccountsResponse,
+  "ReportListInUseStorageAccountsResult",
+  "csharp"
+);
+@@clientName(NotificationEvent, "WebhookNotificationEvent", "csharp");
+@@clientName(OnboardRequest, "AppComplianceOnboardContent", "csharp");
+@@clientName(OnboardResponse, "AppComplianceOnboardResult", "csharp");
+@@clientName(OverviewStatus, "ReportOverviewStatus", "csharp");
+@@clientName(ProvisioningState, "AppComplianceProvisioningState", "csharp");
+@@clientName(Recommendation, "RecommendationDetails", "csharp");
+@@clientName(ReportPatchProperties,
+  "AppComplianceReportPatchProperties",
+  "csharp"
+);
+@@alternateType(ReportPatchProperties.tenantId, uuid, "csharp");
+@@clientName(ReportProperties, "AppComplianceReportProperties", "csharp");
+@@alternateType(ReportProperties.tenantId, uuid, "csharp");
+@@clientName(ReportStatus, "AppComplianceReportStatus", "csharp");
+@@clientName(ResourceItem, "ReportResourceItem", "csharp");
+@@alternateType(ResourceItem.resourceId, armResourceIdentifier, "csharp");
+@@alternateType(ResourceItem.resourceType, armResourceType, "csharp");
+@@clientName(ResourceMetadata, "ReportResourceMetadata", "csharp");
+@@alternateType(ResourceMetadata.resourceId, armResourceIdentifier, "csharp");
+@@alternateType(ResourceMetadata.resourceType, armResourceType, "csharp");
+@@clientName(ResourceOrigin, "ReportResourceOrigin", "csharp");
+@@clientName(ResourceOrigin.AWS, "Aws", "csharp");
+@@clientName(ResourceOrigin.GCP, "Gcp", "csharp");
+@@clientName(ResourceStatus, "ReportResourceStatus", "csharp");
+@@clientName(Responsibility, "CustomerResponsibility", "csharp");
+@@clientName(ResponsibilityEnvironment.AWS, "Aws", "csharp");
+@@clientName(ResponsibilityEnvironment.GCP, "Gcp", "csharp");
+@@clientName(ResponsibilityResource, "ResponsibilityResourceItem", "csharp");
+@@alternateType(ResponsibilityResource.resourceId,
+  armResourceIdentifier,
+  "csharp"
+);
+@@alternateType(ResponsibilityResource.resourceType, armResourceType, "csharp");
+@@clientName(ResponsibilityResource.resourceStatusChangeDate,
+  "ResourceStatusChangedOn",
+  "csharp"
+);
+@@clientName(Result, "ReportResult", "csharp");
+@@clientName(Rule, "QuestionRuleItem", "csharp");
+@@clientName(StatusItem, "OverviewStatusItem", "csharp");
+@@clientName(StorageInfo, "ReportStorageInfo", "csharp");
+@@alternateType(StorageInfo.location, azureLocation, "csharp");
+@@clientName(SyncCertRecordResponse, "SyncCertRecordResult", "csharp");
+@@clientName(TriggerEvaluationResponse, "TriggerEvaluationResult", "csharp");
+@@alternateType(QuickAssessment.resourceId, armResourceIdentifier, "csharp");
+@@clientName(QuickAssessment.timestamp, "CreatedOn", "csharp");
+@@clientName(SnapshotDownloadRequest,
+  "SnapshotDownloadRequestContent",
+  "csharp"
+);
+@@clientName(TriggerEvaluationRequest, "TriggerEvaluationContent", "csharp");
+@@alternateType(SnapshotDownloadRequest.reportCreatorTenantId, uuid, "csharp");
+@@clientName(SyncCertRecordRequest, "SyncCertRecordContent", "csharp");
+@@clientName(EvidenceFileDownloadRequest,
+  "EvidenceFileDownloadRequestContent",
+  "csharp"
+);
+@@alternateType(EvidenceFileDownloadRequest.reportCreatorTenantId,
+  uuid,
+  "csharp"
+);
+@@clientName(ProviderActions.getCollectionCount,
+  "GetCollectionCountProviderAction",
+  "csharp"
+);
+@@clientName(ProviderActions.listInUseStorageAccounts,
+  "GetInUseStorageAccountsProviderAction",
+  "csharp"
+);
+@@clientName(ProviderActions.getOverviewStatus,
+  "GetOverviewStatusProviderAction",
+  "csharp"
+);
+@@clientName(ProviderActions.onboard, "OnboardProviderAction", "csharp");
+@@clientName(ProviderActions.triggerEvaluation,
+  "TriggerEvaluationProviderAction",
+  "csharp"
+);
diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/main.tsp b/specification/appcomplianceautomation/AppComplianceAutomation.Management/main.tsp
index 761e7db631ba..c1ba9b5f2b1c 100644
--- a/specification/appcomplianceautomation/AppComplianceAutomation.Management/main.tsp
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/main.tsp
@@ -3,6 +3,7 @@ import "@typespec/versioning";
 import "@azure-tools/typespec-azure-core";
 import "@azure-tools/typespec-azure-resource-manager";
 import "./models/models.tsp";
+import "./back-compatible.tsp";
 import "./resources/ReportResource.tsp";
 import "./resources/WebhookResource.tsp";
 import "./resources/SnapshotResource.tsp";
diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/EvidenceResource.tsp b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/EvidenceResource.tsp
index 9f4f5d3a9003..5b5260605cd1 100644
--- a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/EvidenceResource.tsp
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/EvidenceResource.tsp
@@ -36,8 +36,6 @@ model EvidenceResource extends Azure.ResourceManager.Foundations.ProxyResource {
   /**
    * Evidence property.
    */
-  #suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
-  @Azure.ClientGenerator.Core.Legacy.flattenProperty("!java")
   properties: EvidenceProperties;
 }
 
diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/ReportResource.tsp b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/ReportResource.tsp
index 18db5de4307d..c0fd92c914f0 100644
--- a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/ReportResource.tsp
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/ReportResource.tsp
@@ -35,8 +35,6 @@ model ReportResource extends Azure.ResourceManager.Foundations.ProxyResource {
   /**
    * Report property.
    */
-  #suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
-  @Azure.ClientGenerator.Core.Legacy.flattenProperty("!java")
   properties: ReportProperties;
 }
 
diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/ScopingConfigurationResource.tsp b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/ScopingConfigurationResource.tsp
index fd8687d20c7e..9770db143cd5 100644
--- a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/ScopingConfigurationResource.tsp
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/ScopingConfigurationResource.tsp
@@ -41,8 +41,6 @@ model ScopingConfigurationResource
   /**
    * ScopingConfiguration property.
    */
-  #suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
-  @Azure.ClientGenerator.Core.Legacy.flattenProperty("!java")
   properties: ScopingConfigurationProperties;
 }
 
diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/SnapshotResource.tsp b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/SnapshotResource.tsp
index 49da5270d5db..9f6198408a07 100644
--- a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/SnapshotResource.tsp
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/SnapshotResource.tsp
@@ -34,8 +34,6 @@ model SnapshotResource extends Azure.ResourceManager.Foundations.ProxyResource {
   /**
    * Snapshot's property.
    */
-  #suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
-  @Azure.ClientGenerator.Core.Legacy.flattenProperty("!java")
   properties?: SnapshotProperties;
 }
 
diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/WebhookResource.tsp b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/WebhookResource.tsp
index 2f407e4eba6e..8671fe1a8819 100644
--- a/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/WebhookResource.tsp
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/resources/WebhookResource.tsp
@@ -40,8 +40,6 @@ model WebhookResource extends Azure.ResourceManager.Foundations.ProxyResource {
   /**
    * Webhook property.
    */
-  #suppress "@azure-tools/typespec-azure-core/no-legacy-usage" "Legacy flatten"
-  @Azure.ClientGenerator.Core.Legacy.flattenProperty("!java")
   properties: WebhookProperties; // Replace 'WebhookProperties' with the actual type
 }
 
diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/routes.tsp b/specification/appcomplianceautomation/AppComplianceAutomation.Management/routes.tsp
index 00e1e5274eed..17cf51956c1e 100644
--- a/specification/appcomplianceautomation/AppComplianceAutomation.Management/routes.tsp
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/routes.tsp
@@ -24,7 +24,11 @@ alias ArmProviderActionAsync<
   Response | ArmAcceptedLroResponse<"Accepted", LroHeaders>,
   BaseParameters = ApiVersionParameter,
   Parameters = Parameters,
-  LroHeaders = ArmLroLocationHeader<Azure.Core.StatusMonitorPollingOptions<ArmOperationStatus>>
+  LroHeaders = ArmLroLocationHeader<
+    Azure.Core.StatusMonitorPollingOptions<ArmOperationStatus>,
+    Response,
+    string
+  >
 >;
 
 alias ArmProviderActionSync<
diff --git a/specification/appcomplianceautomation/AppComplianceAutomation.Management/tspconfig.yaml b/specification/appcomplianceautomation/AppComplianceAutomation.Management/tspconfig.yaml
index 38de71ed0cf2..ca7595869b0d 100644
--- a/specification/appcomplianceautomation/AppComplianceAutomation.Management/tspconfig.yaml
+++ b/specification/appcomplianceautomation/AppComplianceAutomation.Management/tspconfig.yaml
@@ -39,6 +39,9 @@ options:
     generate-fakes: true
     head-as-boolean: true
     inject-spans: true
+  "@azure-typespec/http-client-csharp-mgmt":
+    namespace: "Azure.ResourceManager.AppComplianceAutomation"
+    emitter-output-dir: "{output-dir}/{service-dir}/{namespace}"
 linter:
   extends:
     - "@azure-tools/typespec-azure-rulesets/resource-manager"