diff --git a/packages/http-client-csharp/emitter/src/lib/client-model-builder.ts b/packages/http-client-csharp/emitter/src/lib/client-model-builder.ts
index 097035f7c0..20468746fe 100644
--- a/packages/http-client-csharp/emitter/src/lib/client-model-builder.ts
+++ b/packages/http-client-csharp/emitter/src/lib/client-model-builder.ts
@@ -2,271 +2,200 @@
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
 import {
-  SdkClient,
+  SdkClientType,
   SdkContext,
-  SdkOperationGroup,
+  SdkEndpointParameter,
+  SdkHttpOperation,
+  SdkServiceMethod,
   getAllModels,
-  getHttpOperationWithCache,
-  getLibraryName,
-  listClients,
-  listOperationGroups,
-  listOperationsInOperationGroup,
 } from "@azure-tools/typespec-client-generator-core";
-import {
-  EmitContext,
-  NoTarget,
-  Service,
-  getDoc,
-  getNamespaceFullName,
-  listServices,
-} from "@typespec/compiler";
-import { HttpOperation, getAllHttpServices, getAuthentication, getServers } from "@typespec/http";
-import { getVersions } from "@typespec/versioning";
+import { getDoc } from "@typespec/compiler";
 import { NetEmitterOptions, resolveOptions } from "../options.js";
-import { ClientKind } from "../type/client-kind.js";
 import { CodeModel } from "../type/code-model.js";
 import { InputClient } from "../type/input-client.js";
-import { InputConstant } from "../type/input-constant.js";
 import { InputOperationParameterKind } from "../type/input-operation-parameter-kind.js";
-import { InputOperation } from "../type/input-operation.js";
 import { InputParameter } from "../type/input-parameter.js";
-import { InputEnumType, InputModelType } from "../type/input-type.js";
+import { InputEnumType, InputModelType, InputPrimitiveType } from "../type/input-type.js";
 import { RequestLocation } from "../type/request-location.js";
-import { reportDiagnostic } from "./lib.js";
+import { fromSdkType } from "./converter.js";
 import { Logger } from "./logger.js";
 import { navigateModels } from "./model.js";
-import { loadOperation } from "./operation.js";
+import { fromSdkServiceMethod, getParameterDefaultValue } from "./operation.js";
 import { processServiceAuthentication } from "./service-authentication.js";
-import { resolveServers } from "./typespec-server.js";
-import { createContentTypeOrAcceptParameter } from "./utils.js";
 
 export function createModel(sdkContext: SdkContext<NetEmitterOptions>): CodeModel {
   // initialize tcgc model
   if (!sdkContext.operationModelsMap) getAllModels(sdkContext);
 
-  const services = listServices(sdkContext.emitContext.program);
-  if (services.length === 0) {
-    services.push({
-      type: sdkContext.emitContext.program.getGlobalNamespaceType(),
-    });
-  }
-
-  // TODO: support multiple service. Current only chose the first service.
-  const service = services[0];
-  const serviceNamespaceType = service.type;
-  if (serviceNamespaceType === undefined) {
-    throw Error("Can not emit yaml for a namespace that doesn't exist.");
-  }
-
-  return createModelForService(sdkContext, service);
-}
-
-export function createModelForService(
-  sdkContext: SdkContext<NetEmitterOptions>,
-  service: Service
-): CodeModel {
-  const program = sdkContext.emitContext.program;
-  const serviceNamespaceType = service.type;
-
-  const apiVersions: Set<string> | undefined = new Set<string>();
-  let defaultApiVersion: string | undefined = undefined;
-  let versions = getVersions(program, service.type)[1]
-    ?.getVersions()
-    .map((v) => v.value);
-  const targetApiVersion = sdkContext.emitContext.options["api-version"];
-  if (
-    versions !== undefined &&
-    targetApiVersion !== undefined &&
-    targetApiVersion !== "all" &&
-    targetApiVersion !== "latest"
-  ) {
-    const targetApiVersionIndex = versions.findIndex((v) => v === targetApiVersion);
-    versions = versions.slice(0, targetApiVersionIndex + 1);
-  }
-  if (versions && versions.length > 0) {
-    for (const ver of versions) {
-      apiVersions.add(ver);
-    }
-    defaultApiVersion = versions[versions.length - 1];
-  }
-  const defaultApiVersionConstant: InputConstant | undefined = defaultApiVersion
-    ? {
-        Type: {
-          Kind: "string",
-        },
-        Value: defaultApiVersion,
-      }
-    : undefined;
-
-  const servers = getServers(program, serviceNamespaceType);
-  const namespace = getNamespaceFullName(serviceNamespaceType) || "client";
-  const authentication = getAuthentication(program, serviceNamespaceType);
-  let auth = undefined;
-  if (authentication) {
-    auth = processServiceAuthentication(authentication);
-  }
+  const sdkPackage = sdkContext.sdkPackage;
 
   const modelMap = new Map<string, InputModelType>();
   const enumMap = new Map<string, InputEnumType>();
-  let urlParameters: InputParameter[] | undefined = undefined;
-  let url: string = "";
-  const convenienceOperations: HttpOperation[] = [];
-
-  //create endpoint parameter from servers
-  if (servers !== undefined) {
-    const typespecServers = resolveServers(sdkContext, servers, modelMap, enumMap);
-    if (typespecServers.length > 0) {
-      /* choose the first server as endpoint. */
-      url = typespecServers[0].url;
-      urlParameters = typespecServers[0].parameters;
-    }
-  }
-  const [services] = getAllHttpServices(program);
-  const routes = services[0].operations;
-  if (routes.length === 0) {
-    reportDiagnostic(program, {
-      code: "no-route",
-      format: { service: services[0].namespace.name },
-      target: NoTarget,
-    });
-  }
-  Logger.getInstance().info("routes:" + routes.length);
-
-  const clients: InputClient[] = [];
-  const dpgClients = listClients(sdkContext);
-  for (const client of dpgClients) {
-    clients.push(emitClient(client));
-    addChildClients(sdkContext.emitContext, client, clients);
-  }
 
   navigateModels(sdkContext, modelMap, enumMap);
 
-  for (const client of clients) {
-    for (const op of client.Operations) {
-      const apiVersionIndex = op.Parameters.findIndex(
-        (value: InputParameter) => value.IsApiVersion
-      );
-      if (apiVersionIndex === -1) {
-        continue;
-      }
-      const apiVersionInOperation = op.Parameters[apiVersionIndex];
-      if (defaultApiVersionConstant !== undefined) {
-        if (!apiVersionInOperation.DefaultValue?.Value) {
-          apiVersionInOperation.DefaultValue = defaultApiVersionConstant;
-        }
-      } else {
-        apiVersionInOperation.Kind = InputOperationParameterKind.Method;
-      }
-    }
-  }
+  const rootApiVersions = getRootApiVersions(sdkPackage.clients);
+
+  const inputClients: InputClient[] = [];
+  fromSdkClients(
+    sdkPackage.clients.filter((c) => c.initialization.access === "public"),
+    inputClients,
+    []
+  );
 
   const clientModel = {
-    Name: namespace,
-    ApiVersions: Array.from(apiVersions.values()),
+    Name: sdkPackage.rootNamespace,
+    ApiVersions: rootApiVersions,
     Enums: Array.from(enumMap.values()),
     Models: Array.from(modelMap.values()),
-    Clients: clients,
-    Auth: auth,
+    Clients: inputClients,
+    Auth: processServiceAuthentication(sdkPackage),
   } as CodeModel;
   return clientModel;
 
-  function addChildClients(
-    context: EmitContext<NetEmitterOptions>,
-    client: SdkClient | SdkOperationGroup,
-    clients: InputClient[]
+  function fromSdkClients(
+    clients: SdkClientType<SdkHttpOperation>[],
+    inputClients: InputClient[],
+    parentClientNames: string[]
   ) {
-    const dpgOperationGroups = listOperationGroups(sdkContext, client as SdkClient);
-    for (const dpgGroup of dpgOperationGroups) {
-      const subClient = emitClient(dpgGroup, client);
-      clients.push(subClient);
-      addChildClients(context, dpgGroup, clients);
+    for (const client of clients) {
+      const inputClient = emitClient(client, parentClientNames);
+      inputClients.push(inputClient);
+      const subClients = client.methods
+        .filter((m) => m.kind === "clientaccessor")
+        .map((m) => m.response as SdkClientType<SdkHttpOperation>);
+      parentClientNames.push(inputClient.Name);
+      fromSdkClients(subClients, inputClients, parentClientNames);
+      parentClientNames.pop();
     }
   }
 
-  function getClientName(client: SdkClient | SdkOperationGroup): string {
-    if (client.kind === ClientKind.SdkClient) {
-      return client.name;
-    }
+  function emitClient(client: SdkClientType<SdkHttpOperation>, parentNames: string[]): InputClient {
+    const endpointParameter = client.initialization.properties.find(
+      (p) => p.kind === "endpoint"
+    ) as SdkEndpointParameter;
+    const uri = getMethodUri(endpointParameter);
+    const clientParameters = fromSdkEndpointParameter(endpointParameter);
+    return {
+      Name: getClientName(client, parentNames),
+      Description: client.description,
+      Operations: client.methods
+        .filter((m) => m.kind !== "clientaccessor")
+        .map((m) =>
+          fromSdkServiceMethod(
+            m as SdkServiceMethod<SdkHttpOperation>,
+            uri,
+            clientParameters,
+            rootApiVersions,
+            sdkContext,
+            modelMap,
+            enumMap
+          )
+        ),
+      Protocol: {},
+      Parent: parentNames.length > 0 ? parentNames[parentNames.length - 1] : undefined,
+      Parameters: clientParameters,
+    };
+  }
 
-    const pathParts = client.groupPath.split(".");
-    if (pathParts?.length >= 3) {
-      return pathParts.slice(pathParts.length - 2).join("");
-    }
+  function getClientName(
+    client: SdkClientType<SdkHttpOperation>,
+    parentClientNames: string[]
+  ): string {
+    const clientName = client.name;
+
+    if (parentClientNames.length === 0) return clientName;
+    if (parentClientNames.length >= 2)
+      return `${parentClientNames.slice(parentClientNames.length - 1).join("")}${clientName}`;
 
-    const clientName = getLibraryName(sdkContext, client.type);
     if (
       clientName === "Models" &&
       resolveOptions(sdkContext.emitContext)["model-namespace"] !== false
     ) {
-      reportDiagnostic(program, {
-        code: "invalid-name",
-        format: { name: clientName },
-        target: client.type,
-      });
+      Logger.getInstance().warn(`Invalid client name "${clientName}"`);
       return "ModelsOps";
     }
+
     return clientName;
   }
 
-  function emitClient(
-    client: SdkClient | SdkOperationGroup,
-    parent?: SdkClient | SdkOperationGroup
-  ): InputClient {
-    const operations = listOperationsInOperationGroup(sdkContext, client);
-    let clientDesc = "";
-    if (operations.length > 0) {
-      const container = getHttpOperationWithCache(sdkContext, operations[0]).container;
-      clientDesc = getDoc(program, container) ?? "";
+  function fromSdkEndpointParameter(p: SdkEndpointParameter): InputParameter[] {
+    if (p.type.templateArguments.length === 0)
+      return [
+        {
+          Name: p.name,
+          NameInRequest: p.serializedName ?? p.name,
+          Type: fromSdkType(p.type, sdkContext, modelMap, enumMap),
+          Location: RequestLocation.Uri,
+          IsApiVersion: false,
+          IsResourceParameter: false,
+          IsContentType: false,
+          IsRequired: true,
+          IsEndpoint: true,
+          SkipUrlEncoding: false,
+          Explode: false,
+          Kind: InputOperationParameterKind.Client,
+          DefaultValue: {
+            Type: {
+              Kind: "string",
+            },
+            Value: p.type.serverUrl,
+          },
+        },
+      ];
+
+    // TODO: support free-style endpoint url with multiple parameters
+    const endpointExpr = p.type.serverUrl
+      .replace("https://", "")
+      .replace("http://", "")
+      .split("/")[0];
+    if (!/^\{\w+\}$/.test(endpointExpr))
+      throw new Error(`Unsupported server url "${p.type.serverUrl}"`);
+    const endpointVariableName = endpointExpr.substring(1, endpointExpr.length - 1);
+
+    const parameters: InputParameter[] = [];
+    for (const parameter of p.type.templateArguments) {
+      const isEndpoint = parameter.name === endpointVariableName;
+      const parameterType = isEndpoint
+        ? ({
+            Kind: "uri",
+          } as InputPrimitiveType)
+        : fromSdkType(parameter.type, sdkContext, modelMap, enumMap);
+      parameters.push({
+        Name: parameter.name,
+        NameInRequest: parameter.serializedName,
+        // TODO: remove this workaround after https://github.com/Azure/typespec-azure/issues/1212 is fixed
+        Description: parameter.__raw ? getDoc(sdkContext.program, parameter.__raw) : undefined,
+        // TODO: we should do the magic in generator
+        Type: parameterType,
+        Location: RequestLocation.Uri,
+        IsApiVersion: parameter.isApiVersionParam,
+        IsResourceParameter: false,
+        IsContentType: false,
+        IsRequired: !parameter.optional,
+        IsEndpoint: isEndpoint,
+        SkipUrlEncoding: false,
+        Explode: false,
+        Kind: InputOperationParameterKind.Client,
+        DefaultValue: getParameterDefaultValue(parameter.clientDefaultValue, parameterType),
+      });
     }
+    return parameters;
+  }
+}
 
-    const inputClient: InputClient = {
-      Name: getClientName(client),
-      Description: clientDesc,
-      Operations: [],
-      Protocol: {},
-      Parent: parent === undefined ? undefined : getClientName(parent),
-      Parameters: urlParameters,
-    };
-    for (const op of operations) {
-      const httpOperation = getHttpOperationWithCache(sdkContext, op);
-      const inputOperation: InputOperation = loadOperation(
-        sdkContext,
-        httpOperation,
-        url,
-        urlParameters,
-        serviceNamespaceType,
-        modelMap,
-        enumMap
-      );
+function getRootApiVersions(clients: SdkClientType<SdkHttpOperation>[]): string[] {
+  // find any root client since they should have the same api versions
+  const oneRootClient = clients.find((c) => c.initialization.access === "public");
+  if (!oneRootClient) throw new Error("Root client not found");
 
-      applyDefaultContentTypeAndAcceptParameter(inputOperation);
-      inputClient.Operations.push(inputOperation);
-      if (inputOperation.GenerateConvenienceMethod) convenienceOperations.push(httpOperation);
-    }
-    return inputClient;
-  }
+  return oneRootClient.apiVersions;
 }
 
-function applyDefaultContentTypeAndAcceptParameter(operation: InputOperation): void {
-  const defaultValue: string = "application/json";
-  if (
-    operation.Parameters.some((value) => value.Location === RequestLocation.Body) &&
-    !operation.Parameters.some((value) => value.IsContentType === true)
-  ) {
-    operation.Parameters.push(
-      createContentTypeOrAcceptParameter([defaultValue], "contentType", "Content-Type")
-    );
-    operation.RequestMediaTypes = [defaultValue];
-  }
+function getMethodUri(p: SdkEndpointParameter | undefined): string {
+  if (!p) return "";
 
-  if (
-    !operation.Parameters.some(
-      (value) =>
-        value.Location === RequestLocation.Header && value.NameInRequest.toLowerCase() === "accept"
-    )
-  ) {
-    operation.Parameters.push(
-      createContentTypeOrAcceptParameter([defaultValue], "accept", "Accept")
-    );
-  }
+  if (p.type.templateArguments.length > 0) return p.type.serverUrl;
+
+  return `{${p.name}}`;
 }
diff --git a/packages/http-client-csharp/emitter/src/lib/converter.ts b/packages/http-client-csharp/emitter/src/lib/converter.ts
index a6c0c8acb2..6f4930b0b0 100644
--- a/packages/http-client-csharp/emitter/src/lib/converter.ts
+++ b/packages/http-client-csharp/emitter/src/lib/converter.ts
@@ -52,6 +52,7 @@ export function fromSdkType(
     } as InputNullableType;
   }
   if (sdkType.kind === "model") return fromSdkModelType(sdkType, context, models, enums);
+  if (sdkType.kind === "endpoint") return fromSdkEndpointType();
   if (sdkType.kind === "enum") return fromSdkEnumType(sdkType, context, enums);
   if (sdkType.kind === "enumvalue")
     return fromSdkEnumValueTypeToConstantType(sdkType, context, enums, literalTypeContext);
@@ -64,10 +65,9 @@ export function fromSdkType(
     return fromSdkDateTimeType(sdkType);
   if (sdkType.kind === "duration") return fromSdkDurationType(sdkType as SdkDurationType);
   if (sdkType.kind === "tuple") return fromTupleType();
-  // TODO -- only in operations we could have these types, considering we did not adopt getAllOperations from TCGC yet, this should be fine.
-  // we need to resolve these conversions when we adopt getAllOperations
+  // TODO -- endpoint and credential are handled separately in emitter, since we have specific locations for them in input model.
+  // We can handle unify the way we handle them in the future, probably by chaning the input model schema and do the conversion in generator.
   if (sdkType.kind === "credential") throw new Error("Credential type is not supported yet.");
-  if (sdkType.kind === "endpoint") throw new Error("Endpoint type is not supported yet.");
 
   return fromSdkBuiltInType(sdkType);
 }
@@ -368,3 +368,9 @@ function fromSdkArrayType(
     CrossLanguageDefinitionId: arrayType.crossLanguageDefinitionId,
   };
 }
+
+function fromSdkEndpointType(): InputPrimitiveType {
+  return {
+    Kind: "string",
+  };
+}
diff --git a/packages/http-client-csharp/emitter/src/lib/operation.ts b/packages/http-client-csharp/emitter/src/lib/operation.ts
index e8d13bbf81..ae124d322b 100644
--- a/packages/http-client-csharp/emitter/src/lib/operation.ts
+++ b/packages/http-client-csharp/emitter/src/lib/operation.ts
@@ -1,31 +1,28 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
-import { getLroMetadata } from "@azure-tools/typespec-azure-core";
 import {
+  SdkBodyParameter,
+  SdkBuiltInKinds,
+  SdkBuiltInType,
   SdkContext,
-  UsageFlags,
-  getAccess,
-  isApiVersion,
+  SdkHeaderParameter,
+  SdkHttpOperation,
+  SdkHttpResponse,
+  SdkPathParameter,
+  SdkQueryParameter,
+  SdkServiceMethod,
+  SdkServiceResponseHeader,
+  SdkType,
   shouldGenerateConvenient,
   shouldGenerateProtocol,
+  UsageFlags,
 } from "@azure-tools/typespec-client-generator-core";
-import {
-  Model,
-  ModelProperty,
-  Namespace,
-  Operation,
-  Type,
-  getDeprecated,
-  getDoc,
-  getSummary,
-  isErrorModel,
-} from "@typespec/compiler";
-import { HttpOperation, HttpOperationParameter, HttpOperationResponse } from "@typespec/http";
-import { getExtensions } from "@typespec/openapi";
+import { getDeprecated, getDoc, getSummary, isErrorModel } from "@typespec/compiler";
+import { HttpStatusCodeRange } from "@typespec/http";
 import { getResourceOperation } from "@typespec/rest";
 import { NetEmitterOptions } from "../options.js";
-import { BodyMediaType, typeToBodyMediaType } from "../type/body-media-type.js";
+import { BodyMediaType } from "../type/body-media-type.js";
 import { collectionFormatToDelimMap } from "../type/collection-format.js";
 import { HttpResponseHeader } from "../type/http-response-header.js";
 import { InputConstant } from "../type/input-constant.js";
@@ -33,334 +30,364 @@ import { InputOperationParameterKind } from "../type/input-operation-parameter-k
 import { InputOperation } from "../type/input-operation.js";
 import { InputParameter } from "../type/input-parameter.js";
 import {
-  InputArrayType,
   InputEnumType,
   InputModelType,
+  InputPrimitiveType,
   InputType,
-  isInputEnumType,
-  isInputLiteralType,
-  isInputUnionType,
 } from "../type/input-type.js";
 import { convertLroFinalStateVia } from "../type/operation-final-state-via.js";
-import { OperationLongRunning } from "../type/operation-long-running.js";
 import { OperationPaging } from "../type/operation-paging.js";
 import { OperationResponse } from "../type/operation-response.js";
-import { RequestLocation, requestLocationMap } from "../type/request-location.js";
-import { RequestMethod, parseHttpRequestMethod } from "../type/request-method.js";
-import { getExternalDocs, getOperationId, hasDecorator } from "./decorators.js";
+import { RequestLocation } from "../type/request-location.js";
+import { parseHttpRequestMethod } from "../type/request-method.js";
+import { fromSdkType } from "./converter.js";
+import { getExternalDocs, getOperationId } from "./decorators.js";
 import { Logger } from "./logger.js";
-import { getDefaultValue, getEffectiveSchemaType, getInputType } from "./model.js";
-import { createContentTypeOrAcceptParameter, getTypeName } from "./utils.js";
+import { getInputType } from "./model.js";
 
-export function loadOperation(
-  sdkContext: SdkContext<NetEmitterOptions>,
-  operation: HttpOperation,
+export function fromSdkServiceMethod(
+  method: SdkServiceMethod<SdkHttpOperation>,
   uri: string,
-  urlParameters: InputParameter[] | undefined = undefined,
-  serviceNamespaceType: Namespace,
-  models: Map<string, InputModelType>,
-  enums: Map<string, InputEnumType>
+  clientParameters: InputParameter[],
+  rootApiVersions: string[],
+  sdkContext: SdkContext<NetEmitterOptions>,
+  modelMap: Map<string, InputModelType>,
+  enumMap: Map<string, InputEnumType>
 ): InputOperation {
-  const { path: fullPath, operation: op, verb, parameters: typespecParameters } = operation;
-  const program = sdkContext.program;
-  Logger.getInstance().info(`load operation: ${op.name}, path:${fullPath} `);
-  const resourceOperation = getResourceOperation(program, op);
-  const desc = getDoc(program, op);
-  const summary = getSummary(program, op);
-  const externalDocs = getExternalDocs(sdkContext, op);
-
-  const parameters: InputParameter[] = [];
-  if (urlParameters) {
-    for (const param of urlParameters) {
-      parameters.push(param);
-    }
-  }
-  for (const p of typespecParameters.parameters) {
-    parameters.push(loadOperationParameter(sdkContext, p));
+  let generateConvenience = shouldGenerateConvenient(sdkContext, method.operation.__raw.operation);
+  if (method.operation.verb === "patch" && generateConvenience) {
+    Logger.getInstance().warn(
+      `Convenience method is not supported for PATCH method, it will be automatically turned off. Please set the '@convenientAPI' to false for operation ${method.operation.__raw.operation.name}.`
+    );
+    generateConvenience = false;
   }
 
-  if (typespecParameters.body?.property && !isVoidType(typespecParameters.body.type)) {
-    parameters.push(loadBodyParameter(sdkContext, typespecParameters.body?.property));
-  } else if (typespecParameters.body?.type && !isVoidType(typespecParameters.body.type)) {
-    const rawBodyType = typespecParameters.body.type;
-    const bodyParameter = loadBodyParameter(sdkContext, rawBodyType as Model);
-    const bodyType = bodyParameter.Type;
-    if (bodyType.Kind === "model" && (bodyType.Usage & UsageFlags.Spread) !== 0) {
-      bodyParameter.Kind = InputOperationParameterKind.Spread;
-    }
-    parameters.push(bodyParameter);
-  }
+  return {
+    Name: method.name,
+    ResourceName:
+      getResourceOperation(sdkContext.program, method.operation.__raw.operation)?.resourceType
+        .name ??
+      getOperationGroupName(sdkContext, method.operation, sdkContext.sdkPackage.rootNamespace),
+    Deprecated: getDeprecated(sdkContext.program, method.__raw!),
+    // TODO: we need to figure out how we want to handle summary and description
+    // Right now, we generate garbage <remarks> for some APIs like `Platform-OpenAI-TypeSpec`
+    Summary: getSummary(sdkContext.program, method.__raw!),
+    Description: getDoc(sdkContext.program, method.__raw!),
+    Accessibility: method.access,
+    Parameters: fromSdkOperationParameters(
+      method.operation,
+      clientParameters,
+      rootApiVersions,
+      sdkContext,
+      modelMap,
+      enumMap
+    ),
+    Responses: fromSdkHttpOperationResponses(
+      method.operation.responses,
+      sdkContext,
+      modelMap,
+      enumMap
+    ),
+    HttpMethod: parseHttpRequestMethod(method.operation.verb),
+    RequestBodyMediaType: getBodyMediaType(method.operation.bodyParam?.type),
+    Uri: uri,
+    Path: method.operation.path,
+    ExternalDocsUrl: getExternalDocs(sdkContext, method.operation.__raw.operation)?.url,
+    RequestMediaTypes: getRequestMediaTypes(method.operation),
+    BufferResponse: true,
+    LongRunning: loadLongRunningOperation(method, sdkContext, modelMap, enumMap),
+    Paging: loadOperationPaging(method),
+    GenerateProtocolMethod: shouldGenerateProtocol(sdkContext, method.operation.__raw.operation),
+    GenerateConvenienceMethod: generateConvenience,
+  };
+}
 
-  const responses: OperationResponse[] = [];
-  for (const res of operation.responses) {
-    const operationResponse = loadOperationResponse(sdkContext, res);
-    if (operationResponse) {
-      responses.push(operationResponse);
-    }
-    if (operationResponse?.ContentTypes && operationResponse.ContentTypes.length > 0) {
-      const acceptParameter = createContentTypeOrAcceptParameter(
-        [operationResponse.ContentTypes[0]], // We currently only support one content type per response
-        "accept",
-        "Accept"
-      );
-      const acceptIndex = parameters.findIndex((p) => p.NameInRequest.toLowerCase() === "accept");
-      if (acceptIndex > -1) {
-        parameters.splice(acceptIndex, 1, acceptParameter);
-      } else {
-        parameters.push(acceptParameter);
-      }
-    }
+export function getParameterDefaultValue(
+  clientDefaultValue: any,
+  parameterType: InputType
+): InputConstant | undefined {
+  if (
+    clientDefaultValue === undefined ||
+    // a constant parameter should overwrite client default value
+    parameterType.Kind === "constant"
+  ) {
+    return undefined;
   }
 
-  const mediaTypes: string[] = [];
-  const contentTypeParameter = parameters.find((value) => value.IsContentType);
-  if (contentTypeParameter) {
-    if (isInputLiteralType(contentTypeParameter.Type)) {
-      mediaTypes.push(contentTypeParameter.DefaultValue?.Value);
-    } else if (isInputUnionType(contentTypeParameter.Type)) {
-      for (const unionItem of contentTypeParameter.Type.VariantTypes) {
-        if (isInputLiteralType(unionItem)) {
-          mediaTypes.push(unionItem.Value as string);
-        } else {
-          throw "Media type of content type should be string.";
-        }
-      }
-    } else if (isInputEnumType(contentTypeParameter.Type)) {
-      const mediaTypeValues = contentTypeParameter.Type.Values.map((value) => value.Value);
-      if (mediaTypeValues.some((item) => item === undefined)) {
-        throw "Media type of content type should be string.";
-      }
-      mediaTypes.push(...mediaTypeValues);
-    }
+  return {
+    Type: {
+      Kind: getValueType(clientDefaultValue),
+    },
+    Value: clientDefaultValue,
+  };
+}
+
+function getValueType(value: any): SdkBuiltInKinds {
+  switch (typeof value) {
+    case "string":
+      return "string";
+    case "number":
+      return "int32";
+    case "boolean":
+      return "boolean";
+    case "bigint":
+      return "int64";
+    default:
+      throw new Error(`Unsupported default value type: ${typeof value}`);
   }
+}
 
-  const requestMethod = parseHttpRequestMethod(verb);
-  const generateProtocol: boolean = shouldGenerateProtocol(sdkContext, op);
-  let generateConvenience: boolean = shouldGenerateConvenient(sdkContext, op);
+function fromSdkOperationParameters(
+  operation: SdkHttpOperation,
+  clientParameters: InputParameter[],
+  rootApiVersions: string[],
+  sdkContext: SdkContext<NetEmitterOptions>,
+  modelMap: Map<string, InputModelType>,
+  enumMap: Map<string, InputEnumType>
+): InputParameter[] {
+  const params = clientParameters.concat(
+    operation.parameters.map((p) =>
+      fromSdkHttpOperationParameter(p, rootApiVersions, sdkContext, modelMap, enumMap)
+    )
+  );
+  return operation.bodyParam
+    ? params.concat(
+        fromSdkHttpOperationParameter(
+          operation.bodyParam,
+          rootApiVersions,
+          sdkContext,
+          modelMap,
+          enumMap
+        )
+      )
+    : params;
+}
 
-  if (requestMethod === RequestMethod.PATCH && generateConvenience) {
-    Logger.getInstance().warn(
-      `Convenience method is not supported for PATCH method, it will be automatically turned off. Please set the '@convenientAPI' to false for operation ${op.name}.`
-    );
-    generateConvenience = false;
+// TODO: roll back to SdkMethodParameter when we figure out how to represent the parameter location
+// https://github.com/Azure/typespec-azure/issues/981
+function fromSdkHttpOperationParameter(
+  p: SdkPathParameter | SdkQueryParameter | SdkHeaderParameter | SdkBodyParameter,
+  rootApiVersions: string[],
+  sdkContext: SdkContext<NetEmitterOptions>,
+  modelMap: Map<string, InputModelType>,
+  enumMap: Map<string, InputEnumType>
+): InputParameter {
+  const isContentType =
+    p.kind === "header" && p.serializedName.toLocaleLowerCase() === "content-type";
+  const parameterType = fromSdkType(p.type, sdkContext, modelMap, enumMap);
+  // remove this after: https://github.com/Azure/typespec-azure/issues/1084
+  if (p.type.kind === "bytes") {
+    (parameterType as InputPrimitiveType).Encode = (
+      p.correspondingMethodParams[0].type as SdkBuiltInType
+    ).encode;
   }
+  const format = p.kind === "header" || p.kind === "query" ? p.collectionFormat : undefined;
+  const serializedName = p.kind !== "body" ? p.serializedName : p.name;
 
-  /* handle lro */
-  /* handle paging. */
-  let paging: OperationPaging | undefined = undefined;
-  for (const res of operation.responses) {
-    const body = res.responses[0]?.body;
-    if (body?.type) {
-      const bodyType = getEffectiveSchemaType(sdkContext, body.type);
-      if (bodyType.kind === "Model" && hasDecorator(bodyType, "$pagedResult")) {
-        const itemsProperty = Array.from(bodyType.properties.values()).find((it) =>
-          hasDecorator(it, "$items")
-        );
-        const nextLinkProperty = Array.from(bodyType.properties.values()).find((it) =>
-          hasDecorator(it, "$nextLink")
-        );
-        paging = {
-          NextLinkName: nextLinkProperty?.name,
-          ItemName: itemsProperty?.name,
-        } as OperationPaging;
-      }
-    }
+  return {
+    Name: p.name,
+    NameInRequest: p.kind === "header" ? normalizeHeadername(serializedName) : serializedName,
+    Description: p.description,
+    Type: parameterType,
+    Location: getParameterLocation(p),
+    IsApiVersion:
+      p.name.toLocaleLowerCase() === "apiversion" || p.name.toLocaleLowerCase() === "api-version",
+    IsContentType: isContentType,
+    IsEndpoint: false,
+    Explode: parameterType.Kind === "array" && format === "multi" ? true : false,
+    ArraySerializationDelimiter: format ? collectionFormatToDelimMap[format] : undefined,
+    IsRequired: !p.optional,
+    Kind: getParameterKind(p, parameterType, isContentType, rootApiVersions.length > 0),
+    DefaultValue: getParameterDefaultValue(p.clientDefaultValue, parameterType),
+  } as InputParameter;
+}
+
+function loadLongRunningOperation(
+  method: SdkServiceMethod<SdkHttpOperation>,
+  sdkContext: SdkContext<NetEmitterOptions>,
+  modelMap: Map<string, InputModelType>,
+  enumMap: Map<string, InputEnumType>
+): import("../type/operation-long-running.js").OperationLongRunning | undefined {
+  if (method.kind !== "lro") {
+    return undefined;
   }
-  /* TODO: handle lro */
 
   return {
-    Name: getTypeName(sdkContext, op),
-    ResourceName:
-      resourceOperation?.resourceType.name ??
-      getOperationGroupName(sdkContext, op, serviceNamespaceType),
-    Summary: summary,
-    Deprecated: getDeprecated(program, op),
-    Description: desc,
-    Accessibility: getAccess(sdkContext, op),
-    Parameters: parameters,
-    Responses: responses,
-    HttpMethod: requestMethod,
-    RequestBodyMediaType: typeToBodyMediaType(typespecParameters.body?.type),
-    Uri: uri,
-    Path: fullPath,
-    ExternalDocsUrl: externalDocs?.url,
-    RequestMediaTypes: mediaTypes.length > 0 ? mediaTypes : undefined,
-    BufferResponse: true,
-    LongRunning: loadLongRunningOperation(sdkContext, operation),
-    Paging: paging,
-    GenerateProtocolMethod: generateProtocol,
-    GenerateConvenienceMethod: generateConvenience,
-  } as InputOperation;
+    FinalStateVia: convertLroFinalStateVia(method.__raw_lro_metadata.finalStateVia),
+    FinalResponse: {
+      // in swagger, we allow delete to return some meaningful body content
+      // for now, let assume we don't allow return type
+      StatusCodes: method.operation.verb === "delete" ? [204] : [200],
+      BodyType:
+        method.__raw_lro_metadata.finalEnvelopeResult &&
+        method.__raw_lro_metadata.finalEnvelopeResult !== "void"
+          ? getInputType(
+              sdkContext,
+              method.__raw_lro_metadata.finalEnvelopeResult,
+              modelMap,
+              enumMap,
+              method.operation.__raw.operation
+            )
+          : undefined,
+      BodyMediaType: BodyMediaType.Json,
+    } as OperationResponse,
+    ResultPath: method.__raw_lro_metadata.finalResultPath,
+  };
+}
 
-  function isVoidType(type: Type): boolean {
-    return type.kind === "Intrinsic" && type.name === "void";
+function fromSdkHttpOperationResponses(
+  operationResponses: Map<HttpStatusCodeRange | number, SdkHttpResponse>,
+  sdkContext: SdkContext<NetEmitterOptions>,
+  modelMap: Map<string, InputModelType>,
+  enumMap: Map<string, InputEnumType>
+): OperationResponse[] {
+  const responses: OperationResponse[] = [];
+  operationResponses.forEach((r, range) => {
+    responses.push({
+      StatusCodes: toStatusCodesArray(range),
+      BodyType: r.type ? fromSdkType(r.type, sdkContext, modelMap, enumMap) : undefined,
+      BodyMediaType: BodyMediaType.Json,
+      Headers: fromSdkServiceResponseHeaders(r.headers, sdkContext, modelMap, enumMap),
+      IsErrorResponse: r.type !== undefined && isErrorModel(sdkContext.program, r.type.__raw!),
+      ContentTypes: r.contentTypes,
+    });
+  });
+  return responses;
+}
+
+function fromSdkServiceResponseHeaders(
+  headers: SdkServiceResponseHeader[],
+  sdkContext: SdkContext<NetEmitterOptions>,
+  modelMap: Map<string, InputModelType>,
+  enumMap: Map<string, InputEnumType>
+): HttpResponseHeader[] {
+  return headers.map(
+    (h) =>
+      ({
+        Name: h.__raw!.name,
+        NameInResponse: h.serializedName,
+        Description: h.description,
+        Type: fromSdkType(h.type, sdkContext, modelMap, enumMap),
+      }) as HttpResponseHeader
+  );
+}
+
+function toStatusCodesArray(range: number | HttpStatusCodeRange): number[] {
+  if (typeof range === "number") return [range];
+
+  const statusCodes: number[] = [range.end - range.start + 1];
+  for (let i = range.start; i <= range.end; i++) {
+    statusCodes.push(i);
   }
+  return statusCodes;
+}
 
-  function loadOperationParameter(
-    context: SdkContext<NetEmitterOptions>,
-    parameter: HttpOperationParameter
-  ): InputParameter {
-    const { type: location, name, param } = parameter;
-    const format = parameter.type === "path" ? undefined : parameter.format;
-    const typespecType = param.type;
-    const inputType: InputType = getInputType(context, param, models, enums, operation.operation);
-    let defaultValue: InputConstant | undefined = undefined;
-    const value = getDefaultValue(typespecType);
-    if (value) {
-      defaultValue = {
-        Type: inputType,
-        Value: value,
-      };
-    }
-    const requestLocation = requestLocationMap[location];
-    const isApiVer: boolean = isApiVersion(sdkContext, parameter);
-    const isContentType: boolean =
-      requestLocation === RequestLocation.Header && name.toLowerCase() === "content-type";
-    const kind: InputOperationParameterKind =
-      isContentType || inputType.Kind === "constant"
-        ? InputOperationParameterKind.Constant
-        : isApiVer
-          ? defaultValue
-            ? InputOperationParameterKind.Constant
-            : InputOperationParameterKind.Client
-          : InputOperationParameterKind.Method;
-    return {
-      Name: getTypeName(sdkContext, param),
-      NameInRequest: name,
-      Description: getDoc(program, param),
-      Type: inputType,
-      Location: requestLocation,
-      DefaultValue: defaultValue,
-      IsRequired: !param.optional,
-      IsApiVersion: isApiVer,
-      IsResourceParameter: false,
-      IsContentType: isContentType,
-      IsEndpoint: false,
-      SkipUrlEncoding:
-        // TODO: update this when https://github.com/Azure/typespec-azure/issues/1022 is resolved
-        getExtensions(program, param).get("x-ms-skip-url-encoding") === true,
-      Explode: (inputType as InputArrayType).ValueType && format === "multi" ? true : false,
-      Kind: kind,
-      ArraySerializationDelimiter: format ? collectionFormatToDelimMap[format] : undefined,
-    } as InputParameter;
+function getBodyMediaType(type: SdkType | undefined) {
+  if (type === undefined) {
+    return BodyMediaType.None;
   }
 
-  function loadBodyParameter(
-    context: SdkContext<NetEmitterOptions>,
-    body: ModelProperty | Model
-  ): InputParameter {
-    const inputType: InputType = getInputType(context, body, models, enums, operation.operation);
-    const requestLocation = RequestLocation.Body;
-    const kind: InputOperationParameterKind = InputOperationParameterKind.Method;
-    return {
-      Name: getTypeName(context, body),
-      NameInRequest: body.name,
-      Description: getDoc(program, body),
-      Type: inputType,
-      Location: requestLocation,
-      IsRequired: body.kind === "Model" ? true : !body.optional,
-      IsApiVersion: false,
-      IsResourceParameter: false,
-      IsContentType: false,
-      IsEndpoint: false,
-      SkipUrlEncoding: false,
-      Explode: false,
-      Kind: kind,
-    } as InputParameter;
+  if (type.kind === "model") {
+    return BodyMediaType.Json;
+  } else if (type.kind === "string") {
+    return BodyMediaType.Text;
+  } else if (type.kind === "bytes") {
+    return BodyMediaType.Binary;
   }
+  return BodyMediaType.None;
+}
 
-  function loadOperationResponse(
-    context: SdkContext<NetEmitterOptions>,
-    response: HttpOperationResponse
-  ): OperationResponse | undefined {
-    if (!response.statusCode || response.statusCode === "*") {
-      return undefined;
-    }
-    const status: number[] = [];
-    status.push(Number(response.statusCode));
-    //TODO: what to do if more than 1 response?
-    const body = response.responses[0]?.body;
+function getRequestMediaTypes(op: SdkHttpOperation): string[] | undefined {
+  const contentTypes = op.parameters.filter(
+    (p) => p.kind === "header" && p.serializedName.toLocaleLowerCase() === "content-type"
+  );
+  if (contentTypes.length === 0) return undefined;
+  return contentTypes.map((p) => getMediaTypes(p.type)).flat();
+}
 
-    let type: InputType | undefined = undefined;
-    if (body?.type) {
-      const typespecType = getEffectiveSchemaType(context, body.type);
-      const inputType: InputType = getInputType(
-        context,
-        typespecType,
-        models,
-        enums,
-        operation.operation
-      );
-      type = inputType;
+function getMediaTypes(type: SdkType): string[] {
+  if (type.kind === "constant") {
+    if (type.valueType.kind !== "string") {
+      throw `Media type in "content-type" should be string. But get ${type.valueType.kind}.`;
     }
-
-    const headers = response.responses[0]?.headers;
-    const responseHeaders: HttpResponseHeader[] = [];
-    if (headers) {
-      for (const key of Object.keys(headers)) {
-        responseHeaders.push({
-          Name: key,
-          NameInResponse: headers[key].name,
-          Description: getDoc(program, headers[key]) ?? "",
-          Type: getInputType(context, headers[key].type, models, enums, operation.operation),
-        } as HttpResponseHeader);
+    return [type.value as string];
+  } else if (type.kind === "union") {
+    const mediaTypes: string[] = [];
+    for (const unionItem of type.values) {
+      if (unionItem.kind === "constant" && unionItem.valueType.kind === "string") {
+        mediaTypes.push(unionItem.value as string);
+      } else {
+        throw `Media type in "content-type" should be string. But get ${unionItem.kind}.`;
       }
     }
+    return mediaTypes;
+  } else if (type.kind === "enum") {
+    if (type.valueType.kind !== "string") {
+      throw `Media type in "content-type" should be string. But get ${type.valueType.kind}.`;
+    }
+    return type.values.map((v) => v.value as string);
+  }
+  return [];
+}
 
-    return {
-      StatusCodes: status,
-      BodyType: type,
-      BodyMediaType: BodyMediaType.Json,
-      Headers: responseHeaders,
-      IsErrorResponse: isErrorModel(program, response.type),
-      ContentTypes: body?.contentTypes,
-    } as OperationResponse;
+function loadOperationPaging(
+  method: SdkServiceMethod<SdkHttpOperation>
+): OperationPaging | undefined {
+  if (method.kind !== "paging") {
+    return undefined;
   }
 
-  function loadLongRunningOperation(
-    context: SdkContext<NetEmitterOptions>,
-    op: HttpOperation
-  ): OperationLongRunning | undefined {
-    const metadata = getLroMetadata(program, op.operation);
-    if (metadata === undefined) {
-      return undefined;
-    }
+  return {
+    ItemName: method.__raw_paged_metadata.itemsProperty?.name,
+    NextLinkName: method.__raw_paged_metadata.nextLinkProperty?.name,
+  };
+}
 
-    let bodyType = undefined;
-    if (
-      op.verb !== "delete" &&
-      metadata.finalResult !== undefined &&
-      metadata.finalResult !== "void"
-    ) {
-      bodyType = getInputType(
-        context,
-        metadata.finalEnvelopeResult as Model,
-        models,
-        enums,
-        op.operation
-      );
-    }
+// TODO: https://github.com/Azure/typespec-azure/issues/981
+function getParameterLocation(
+  p: SdkPathParameter | SdkQueryParameter | SdkHeaderParameter | SdkBodyParameter | undefined
+): RequestLocation {
+  switch (p?.kind) {
+    case "path":
+      return RequestLocation.Path;
+    case "header":
+      return RequestLocation.Header;
+    case "query":
+      return RequestLocation.Query;
+    case "body":
+      return RequestLocation.Body;
+    default:
+      return RequestLocation.None;
+  }
+}
 
-    return {
-      FinalStateVia: convertLroFinalStateVia(metadata.finalStateVia),
-      FinalResponse: {
-        // in swagger, we allow delete to return some meaningful body content
-        // for now, let assume we don't allow return type
-        StatusCodes: op.verb === "delete" ? [204] : [200],
-        BodyType: bodyType,
-        BodyMediaType: BodyMediaType.Json,
-      } as OperationResponse,
-      ResultPath: metadata.finalResultPath,
-    } as OperationLongRunning;
+function getParameterKind(
+  p: SdkPathParameter | SdkQueryParameter | SdkHeaderParameter | SdkBodyParameter,
+  type: InputType,
+  isContentType: boolean,
+  hasGlobalApiVersion: boolean
+): InputOperationParameterKind {
+  if (p.kind === "body") {
+    if (type.Kind === "model" && (type.Usage & UsageFlags.Spread) !== 0) {
+      return InputOperationParameterKind.Spread;
+    }
+    return InputOperationParameterKind.Method;
   }
+  return isContentType || type.Kind === "constant"
+    ? InputOperationParameterKind.Constant
+    : p.isApiVersionParam
+      ? hasGlobalApiVersion
+        ? InputOperationParameterKind.Client
+        : InputOperationParameterKind.Method
+      : InputOperationParameterKind.Method;
 }
 
 function getOperationGroupName(
   context: SdkContext,
-  operation: Operation,
-  serviceNamespaceType: Namespace
+  operation: SdkHttpOperation,
+  namespace: string
 ): string {
-  const explicitOperationId = getOperationId(context, operation);
+  const explicitOperationId = getOperationId(context, operation.__raw.operation);
   if (explicitOperationId) {
     const ids: string[] = explicitOperationId.split("_");
     if (ids.length > 1) {
@@ -368,14 +395,23 @@ function getOperationGroupName(
     }
   }
 
-  if (operation.interface) {
-    return operation.interface.name;
+  if (operation.__raw.operation.interface) {
+    return operation.__raw.operation.interface.name;
   }
-  let namespace = operation.namespace;
-  if (!namespace) {
-    namespace = context.program.checker.getGlobalNamespaceType() ?? serviceNamespaceType;
+  if (operation.__raw.operation.namespace) {
+    return operation.__raw.operation.namespace.name;
   }
+  return namespace;
+}
 
-  if (namespace) return namespace.name;
-  else return "";
+// TODO: remove after https://github.com/Azure/typespec-azure/issues/1227 is fixed
+function normalizeHeadername(name: string): string {
+  switch (name.toLocaleLowerCase()) {
+    case "accept":
+      return "Accept";
+    case "content-type":
+      return "Content-Type";
+    default:
+      return name;
+  }
 }
diff --git a/packages/http-client-csharp/emitter/src/lib/service-authentication.ts b/packages/http-client-csharp/emitter/src/lib/service-authentication.ts
index 51e85900df..2def6f3e9c 100644
--- a/packages/http-client-csharp/emitter/src/lib/service-authentication.ts
+++ b/packages/http-client-csharp/emitter/src/lib/service-authentication.ts
@@ -1,61 +1,100 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
-import { Authentication } from "@typespec/http";
-import { InputApiKeyAuth } from "../type/input-api-key-auth.js";
+import {
+  SdkCredentialParameter,
+  SdkCredentialType,
+  SdkHttpOperation,
+  SdkPackage,
+} from "@azure-tools/typespec-client-generator-core";
+import { Oauth2Auth, OAuth2Flow } from "@typespec/http";
 import { InputAuth } from "../type/input-auth.js";
-import { InputOAuth2Auth } from "../type/input-oauth2-auth.js";
 import { Logger } from "./logger.js";
 
-export function processServiceAuthentication(authentication: Authentication): InputAuth {
-  const auth = {} as InputAuth;
-  let scopes: Set<string> | undefined;
+export function processServiceAuthentication(
+  sdkPackage: SdkPackage<SdkHttpOperation>
+): InputAuth | undefined {
+  let authClientParameter: SdkCredentialParameter | undefined = undefined;
+  for (const client of sdkPackage.clients) {
+    for (const parameter of client.initialization.properties) {
+      if (parameter.kind === "credential") {
+        authClientParameter = parameter;
+        break;
+      }
+    }
+  }
 
-  for (const option of authentication.options) {
-    for (const scheme of option.schemes) {
-      switch (scheme.type) {
-        case "apiKey":
-          auth.ApiKey = { Name: scheme.name } as InputApiKeyAuth;
-          break;
-        case "oauth2":
-          for (const flow of scheme.flows) {
-            if (flow.scopes) {
-              scopes ??= new Set<string>();
-              for (const scope of flow.scopes) {
-                scopes.add(scope.value);
-              }
-            }
-          }
-          break;
-        case "http":
-          const schemeOrApiKeyPrefix = scheme.scheme;
-          if (schemeOrApiKeyPrefix === "basic") {
+  if (!authClientParameter) {
+    return undefined;
+  }
+  if (authClientParameter.type.kind === "credential") {
+    return processAuthType(authClientParameter.type);
+  }
+  const inputAuth: InputAuth = {};
+  for (const authType of authClientParameter.type.values) {
+    // TODO: TCGC might change to []SdkCredentialType
+    const auth = processAuthType(authType as SdkCredentialType);
+    if (auth?.ApiKey) {
+      inputAuth.ApiKey = auth.ApiKey;
+    }
+    if (auth?.OAuth2) {
+      inputAuth.OAuth2 = auth.OAuth2;
+    }
+  }
+  return inputAuth;
+}
+
+function processAuthType(credentialType: SdkCredentialType): InputAuth | undefined {
+  const scheme = credentialType.scheme;
+  switch (scheme.type) {
+    case "apiKey":
+      return { ApiKey: { Name: scheme.name } } as InputAuth;
+    case "oauth2":
+      return processOAuth2(scheme);
+    case "http":
+      {
+        const schemeOrApiKeyPrefix = scheme.scheme;
+        switch (schemeOrApiKeyPrefix) {
+          case "basic":
             Logger.getInstance().warn(
-              `{schemeOrApiKeyPrefix} auth method is currently not supported.`
+              `${schemeOrApiKeyPrefix} auth method is currently not supported.`
             );
-          } else if (schemeOrApiKeyPrefix === "bearer") {
-            auth.ApiKey = {
-              Name: "Authorization",
-              Prefix: "Bearer",
-            } as InputApiKeyAuth;
-          } else {
-            auth.ApiKey = {
-              Name: "Authorization",
-              Prefix: schemeOrApiKeyPrefix,
-            } as InputApiKeyAuth;
-          }
-          break;
-        default:
-          throw new Error("Not supported authentication.");
+            return undefined;
+          case "bearer":
+            return {
+              ApiKey: {
+                Name: "Authorization",
+                Prefix: "Bearer",
+              },
+            } as InputAuth;
+          default:
+            return {
+              ApiKey: {
+                Name: "Authorization",
+                Prefix: schemeOrApiKeyPrefix,
+              },
+            } as InputAuth;
+        }
       }
-    }
+      break;
+    default:
+      throw new Error(`un-supported authentication scheme ${scheme.type}`);
   }
+}
 
-  if (scopes) {
-    auth.OAuth2 = {
-      Scopes: Array.from(scopes.values()),
-    } as InputOAuth2Auth;
+function processOAuth2(scheme: Oauth2Auth<OAuth2Flow[]>): InputAuth | undefined {
+  let scopes: Set<string> | undefined = undefined;
+  for (const flow of scheme.flows) {
+    if (flow.scopes) {
+      scopes ??= new Set<string>();
+      for (const scope of flow.scopes) {
+        scopes.add(scope.value);
+      }
+    }
   }
-
-  return auth;
+  return scopes
+    ? ({
+        OAuth2: { Scopes: Array.from(scopes.values()) },
+      } as InputAuth)
+    : undefined;
 }
diff --git a/packages/http-client-csharp/emitter/src/lib/utils.ts b/packages/http-client-csharp/emitter/src/lib/utils.ts
index 05cf2d680c..aec553beaf 100644
--- a/packages/http-client-csharp/emitter/src/lib/utils.ts
+++ b/packages/http-client-csharp/emitter/src/lib/utils.ts
@@ -68,5 +68,5 @@ export function createContentTypeOrAcceptParameter(
             Value: mediaTypes[0],
           } as InputConstant)
         : undefined,
-  } as InputParameter;
+  };
 }
diff --git a/packages/http-client-csharp/emitter/test/Unit/encode.test.ts b/packages/http-client-csharp/emitter/test/Unit/encode.test.ts
index 3eeb9d02a7..b2bc4dbdc5 100644
--- a/packages/http-client-csharp/emitter/test/Unit/encode.test.ts
+++ b/packages/http-client-csharp/emitter/test/Unit/encode.test.ts
@@ -2,7 +2,7 @@ import { TestHost } from "@typespec/compiler/testing";
 import { getAllHttpServices } from "@typespec/http";
 import assert, { deepStrictEqual } from "assert";
 import { beforeEach, describe, it } from "vitest";
-import { loadOperation } from "../../src/lib/operation.js";
+import { createModel } from "../../src/lib/client-model-builder.js";
 import { InputDurationType, InputEnumType, InputModelType } from "../../src/type/input-type.js";
 import {
   createEmitterContext,
@@ -32,18 +32,7 @@ describe("Test encode duration", () => {
     );
     const context = createEmitterContext(program);
     const sdkContext = createNetSdkContext(context);
-    const [services] = getAllHttpServices(program);
-    const modelMap = new Map<string, InputModelType>();
-    const enumMap = new Map<string, InputEnumType>();
-    const operation = loadOperation(
-      sdkContext,
-      services[0].operations[0],
-      "",
-      [],
-      services[0].namespace,
-      modelMap,
-      enumMap
-    );
+    const root = createModel(sdkContext);
     deepStrictEqual(
       {
         Kind: "duration",
@@ -53,7 +42,7 @@ describe("Test encode duration", () => {
           Encode: undefined,
         },
       } as InputDurationType,
-      operation.Parameters[0].Type
+      root.Clients[0].Operations[0].Parameters[1].Type
     );
   });
 
@@ -70,18 +59,7 @@ describe("Test encode duration", () => {
     );
     const context = createEmitterContext(program);
     const sdkContext = createNetSdkContext(context);
-    const [services] = getAllHttpServices(program);
-    const modelMap = new Map<string, InputModelType>();
-    const enumMap = new Map<string, InputEnumType>();
-    const operation = loadOperation(
-      sdkContext,
-      services[0].operations[0],
-      "",
-      [],
-      services[0].namespace,
-      modelMap,
-      enumMap
-    );
+    const root = createModel(sdkContext);
     deepStrictEqual(
       {
         Kind: "duration",
@@ -91,7 +69,7 @@ describe("Test encode duration", () => {
           Encode: undefined,
         },
       } as InputDurationType,
-      operation.Parameters[0].Type
+      root.Clients[0].Operations[0].Parameters[1].Type
     );
   });
 
@@ -108,18 +86,7 @@ describe("Test encode duration", () => {
     );
     const context = createEmitterContext(program);
     const sdkContext = createNetSdkContext(context);
-    const [services] = getAllHttpServices(program);
-    const modelMap = new Map<string, InputModelType>();
-    const enumMap = new Map<string, InputEnumType>();
-    const operation = loadOperation(
-      sdkContext,
-      services[0].operations[0],
-      "",
-      [],
-      services[0].namespace,
-      modelMap,
-      enumMap
-    );
+    const root = createModel(sdkContext);
     deepStrictEqual(
       {
         Kind: "duration",
@@ -129,7 +96,7 @@ describe("Test encode duration", () => {
           Encode: undefined,
         },
       } as InputDurationType,
-      operation.Parameters[0].Type
+      root.Clients[0].Operations[0].Parameters[1].Type
     );
   });
 
diff --git a/packages/http-client-csharp/emitter/test/Unit/property-type.test.ts b/packages/http-client-csharp/emitter/test/Unit/property-type.test.ts
index f904b1cb3b..fdd99e58af 100644
--- a/packages/http-client-csharp/emitter/test/Unit/property-type.test.ts
+++ b/packages/http-client-csharp/emitter/test/Unit/property-type.test.ts
@@ -28,7 +28,7 @@ describe("Test GetInputType for array", () => {
     const context = createEmitterContext(program);
     const sdkContext = createNetSdkContext(context);
     const root = createModel(sdkContext);
-    const type = root.Clients[0].Operations[0].Parameters[0].Type;
+    const type = root.Clients[0].Operations[0].Parameters[3].Type;
     strictEqual(type.Kind, "array");
     strictEqual(type.CrossLanguageDefinitionId, "TypeSpec.Array");
     strictEqual(type.ValueType.Kind, "string");
@@ -82,7 +82,7 @@ describe("Test GetInputType for enum", () => {
     const context = createEmitterContext(program);
     const sdkContext = createNetSdkContext(context);
     const root = createModel(sdkContext);
-    const type = root.Clients[0].Operations[0].Parameters[0].Type;
+    const type = root.Clients[0].Operations[0].Parameters[3].Type;
     strictEqual(type.Kind, "enum");
     strictEqual(type.Name, "SimpleEnum");
     strictEqual(type.IsExtensible, false);
@@ -124,7 +124,7 @@ describe("Test GetInputType for enum", () => {
     const context = createEmitterContext(program);
     const sdkContext = createNetSdkContext(context);
     const root = createModel(sdkContext);
-    const type = root.Clients[0].Operations[0].Parameters[0].Type;
+    const type = root.Clients[0].Operations[0].Parameters[3].Type;
     strictEqual(type.Kind, "enum");
     strictEqual(type.Name, "FixedIntEnum");
     strictEqual(type.CrossLanguageDefinitionId, "Azure.Csharp.Testing.FixedIntEnum");
@@ -158,7 +158,7 @@ describe("Test GetInputType for enum", () => {
     const context = createEmitterContext(program);
     const sdkContext = createNetSdkContext(context);
     const root = createModel(sdkContext);
-    const type = root.Clients[0].Operations[0].Parameters[0].Type;
+    const type = root.Clients[0].Operations[0].Parameters[3].Type;
     strictEqual(type.Kind, "enum");
     strictEqual(type.Name, "FixedEnum");
     strictEqual(type.CrossLanguageDefinitionId, "Azure.Csharp.Testing.FixedEnum");
diff --git a/packages/http-client-csharp/emitter/test/Unit/scalar.test.ts b/packages/http-client-csharp/emitter/test/Unit/scalar.test.ts
index ccbdfbd667..2c14f5f8a2 100644
--- a/packages/http-client-csharp/emitter/test/Unit/scalar.test.ts
+++ b/packages/http-client-csharp/emitter/test/Unit/scalar.test.ts
@@ -28,13 +28,13 @@ describe("Test GetInputType for scalar", () => {
     const context = createEmitterContext(program);
     const sdkContext = createNetSdkContext(context);
     const root = createModel(sdkContext);
-    deepStrictEqual(root.Clients[0].Operations[0].Parameters[0].Type.Kind, "azureLocation");
+    deepStrictEqual(root.Clients[0].Operations[0].Parameters[1].Type.Kind, "azureLocation");
     deepStrictEqual(
       {
         Kind: "azureLocation",
         Encode: "string",
       },
-      root.Clients[0].Operations[0].Parameters[0].Type
+      root.Clients[0].Operations[0].Parameters[1].Type
     );
   });
 });
diff --git a/packages/http-client-csharp/emitter/test/Unit/string-format.test.ts b/packages/http-client-csharp/emitter/test/Unit/string-format.test.ts
index a31cd0d4ff..2f8f8347b6 100644
--- a/packages/http-client-csharp/emitter/test/Unit/string-format.test.ts
+++ b/packages/http-client-csharp/emitter/test/Unit/string-format.test.ts
@@ -2,7 +2,7 @@ import { TestHost } from "@typespec/compiler/testing";
 import { getAllHttpServices } from "@typespec/http";
 import assert, { deepStrictEqual } from "assert";
 import { beforeEach, describe, it } from "vitest";
-import { loadOperation } from "../../src/lib/operation.js";
+import { createModel } from "../../src/lib/client-model-builder.js";
 import { InputEnumType, InputModelType, InputPrimitiveType } from "../../src/type/input-type.js";
 import {
   createEmitterContext,
@@ -28,24 +28,13 @@ describe("Test string format", () => {
     );
     const context = createEmitterContext(program);
     const sdkContext = createNetSdkContext(context);
-    const [services] = getAllHttpServices(program);
-    const modelMap = new Map<string, InputModelType>();
-    const enumMap = new Map<string, InputEnumType>();
-    const operation = loadOperation(
-      sdkContext,
-      services[0].operations[0],
-      "",
-      [],
-      services[0].namespace,
-      modelMap,
-      enumMap
-    );
+    const root = createModel(sdkContext);
     deepStrictEqual(
       {
         Kind: "url",
         Encode: undefined,
       } as InputPrimitiveType,
-      operation.Parameters[0].Type
+      root.Clients[0].Operations[0].Parameters[1].Type
     );
   });
 
diff --git a/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/InputLiteralType.cs b/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/InputLiteralType.cs
index 7db00875d8..5f2b455b9a 100644
--- a/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/InputLiteralType.cs
+++ b/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/InputLiteralType.cs
@@ -13,5 +13,7 @@ public InputLiteralType(InputType valueType, object value) : base("Literal")
 
         public InputType ValueType { get; }
         public object Value { get; }
+
+        public static implicit operator InputConstant(InputLiteralType literal) => new(literal.Value, literal.ValueType);
     }
 }
diff --git a/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/Serialization/TypeSpecInputParameterConverter.cs b/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/Serialization/TypeSpecInputParameterConverter.cs
index bdbf16fd30..f7121c0a99 100644
--- a/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/Serialization/TypeSpecInputParameterConverter.cs
+++ b/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/Serialization/TypeSpecInputParameterConverter.cs
@@ -91,7 +91,8 @@ public static InputParameter CreateInputParameter(ref Utf8JsonReader reader, str
                 description: description,
                 type: parameterType,
                 location: requestLocation,
-                defaultValue: defaultValue,
+                // TODO: not use default value for constant value https://github.com/microsoft/typespec/issues/4028
+                defaultValue: parameterType is InputLiteralType { Value: not null } literalType ? literalType : defaultValue,
                 kind: parameterKind,
                 isRequired: isRequired,
                 isApiVersion: isApiVersion,
diff --git a/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/Serialization/TypeSpecInputTypeConverter.cs b/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/Serialization/TypeSpecInputTypeConverter.cs
index fbadc5f4ea..04f7fdbf30 100644
--- a/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/Serialization/TypeSpecInputTypeConverter.cs
+++ b/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/Serialization/TypeSpecInputTypeConverter.cs
@@ -62,7 +62,7 @@ private InputType CreateObject(ref Utf8JsonReader reader, JsonSerializerOptions
 
         private InputType CreateDerivedType(ref Utf8JsonReader reader, string? id, string? kind, string? name, JsonSerializerOptions options) => kind switch
         {
-            null => throw new JsonException("InputType must have a 'Kind' property"),
+            null => throw new JsonException($"InputType (id: '{id}', name: '{name}') must have a 'Kind' property"),
             LiteralKind => TypeSpecInputLiteralTypeConverter.CreateInputLiteralType(ref reader, id, name, options, _referenceHandler.CurrentResolver),
             UnionKind => TypeSpecInputUnionTypeConverter.CreateInputUnionType(ref reader, id, name, options, _referenceHandler.CurrentResolver),
             ModelKind => TypeSpecInputModelTypeConverter.CreateModelType(ref reader, id, name, options, _referenceHandler.CurrentResolver),
diff --git a/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/api-key/tspCodeModel.json b/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/api-key/tspCodeModel.json
index a884cf4336..07cd5099b8 100644
--- a/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/api-key/tspCodeModel.json
+++ b/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/api-key/tspCodeModel.json
@@ -41,9 +41,8 @@
      "Parameters": [
       {
        "$id": "7",
-       "Name": "host",
-       "NameInRequest": "host",
-       "Description": "TestServer endpoint",
+       "Name": "endpoint",
+       "NameInRequest": "endpoint",
        "Type": {
         "$id": "8",
         "Kind": "string"
@@ -65,36 +64,11 @@
         },
         "Value": "http://localhost:3000"
        }
-      },
-      {
-       "$id": "11",
-       "Name": "accept",
-       "NameInRequest": "Accept",
-       "Type": {
-        "$id": "12",
-        "Kind": "string"
-       },
-       "Location": "Header",
-       "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
-       "IsRequired": true,
-       "IsEndpoint": false,
-       "SkipUrlEncoding": false,
-       "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "13",
-        "Type": {
-         "$ref": "12"
-        },
-        "Value": "application/json"
-       }
       }
      ],
      "Responses": [
       {
-       "$id": "14",
+       "$id": "11",
        "StatusCodes": [
         204
        ],
@@ -105,14 +79,14 @@
      ],
      "HttpMethod": "GET",
      "RequestBodyMediaType": "None",
-     "Uri": "{host}",
+     "Uri": "{endpoint}",
      "Path": "/authentication/api-key/valid",
      "BufferResponse": true,
      "GenerateProtocolMethod": true,
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "15",
+     "$id": "12",
      "Name": "invalid",
      "ResourceName": "ApiKey",
      "Description": "Check whether client is authenticated.",
@@ -122,60 +96,41 @@
        "$ref": "7"
       },
       {
-       "$id": "16",
+       "$id": "13",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "17",
-        "Kind": "string"
+        "$id": "14",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "15",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "18",
-        "Type": {
-         "$ref": "17"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       }
      ],
      "Responses": [
       {
-       "$id": "19",
+       "$id": "16",
        "StatusCodes": [
         204
        ],
        "BodyMediaType": "Json",
        "Headers": [],
        "IsErrorResponse": false
-      },
-      {
-       "$id": "20",
-       "StatusCodes": [
-        403
-       ],
-       "BodyType": {
-        "$ref": "2"
-       },
-       "BodyMediaType": "Json",
-       "Headers": [],
-       "IsErrorResponse": true,
-       "ContentTypes": [
-        "application/json"
-       ]
       }
      ],
      "HttpMethod": "GET",
      "RequestBodyMediaType": "None",
-     "Uri": "{host}",
+     "Uri": "{endpoint}",
      "Path": "/authentication/api-key/invalid",
      "BufferResponse": true,
      "GenerateProtocolMethod": true,
@@ -183,7 +138,7 @@
     }
    ],
    "Protocol": {
-    "$id": "21"
+    "$id": "17"
    },
    "Parameters": [
     {
@@ -193,9 +148,9 @@
   }
  ],
  "Auth": {
-  "$id": "22",
+  "$id": "18",
   "ApiKey": {
-   "$id": "23",
+   "$id": "19",
    "Name": "x-ms-api-key"
   }
  }
diff --git a/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/http/custom/tspCodeModel.json b/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/http/custom/tspCodeModel.json
index e82b79c317..336a0c648a 100644
--- a/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/http/custom/tspCodeModel.json
+++ b/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/http/custom/tspCodeModel.json
@@ -41,9 +41,8 @@
      "Parameters": [
       {
        "$id": "7",
-       "Name": "host",
-       "NameInRequest": "host",
-       "Description": "TestServer endpoint",
+       "Name": "endpoint",
+       "NameInRequest": "endpoint",
        "Type": {
         "$id": "8",
         "Kind": "string"
@@ -65,36 +64,11 @@
         },
         "Value": "http://localhost:3000"
        }
-      },
-      {
-       "$id": "11",
-       "Name": "accept",
-       "NameInRequest": "Accept",
-       "Type": {
-        "$id": "12",
-        "Kind": "string"
-       },
-       "Location": "Header",
-       "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
-       "IsRequired": true,
-       "IsEndpoint": false,
-       "SkipUrlEncoding": false,
-       "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "13",
-        "Type": {
-         "$ref": "12"
-        },
-        "Value": "application/json"
-       }
       }
      ],
      "Responses": [
       {
-       "$id": "14",
+       "$id": "11",
        "StatusCodes": [
         204
        ],
@@ -105,14 +79,14 @@
      ],
      "HttpMethod": "GET",
      "RequestBodyMediaType": "None",
-     "Uri": "{host}",
+     "Uri": "{endpoint}",
      "Path": "/authentication/http/custom/valid",
      "BufferResponse": true,
      "GenerateProtocolMethod": true,
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "15",
+     "$id": "12",
      "Name": "invalid",
      "ResourceName": "Custom",
      "Description": "Check whether client is authenticated.",
@@ -122,60 +96,41 @@
        "$ref": "7"
       },
       {
-       "$id": "16",
+       "$id": "13",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "17",
-        "Kind": "string"
+        "$id": "14",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "15",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "18",
-        "Type": {
-         "$ref": "17"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       }
      ],
      "Responses": [
       {
-       "$id": "19",
+       "$id": "16",
        "StatusCodes": [
         204
        ],
        "BodyMediaType": "Json",
        "Headers": [],
        "IsErrorResponse": false
-      },
-      {
-       "$id": "20",
-       "StatusCodes": [
-        403
-       ],
-       "BodyType": {
-        "$ref": "2"
-       },
-       "BodyMediaType": "Json",
-       "Headers": [],
-       "IsErrorResponse": true,
-       "ContentTypes": [
-        "application/json"
-       ]
       }
      ],
      "HttpMethod": "GET",
      "RequestBodyMediaType": "None",
-     "Uri": "{host}",
+     "Uri": "{endpoint}",
      "Path": "/authentication/http/custom/invalid",
      "BufferResponse": true,
      "GenerateProtocolMethod": true,
@@ -183,7 +138,7 @@
     }
    ],
    "Protocol": {
-    "$id": "21"
+    "$id": "17"
    },
    "Parameters": [
     {
@@ -193,9 +148,9 @@
   }
  ],
  "Auth": {
-  "$id": "22",
+  "$id": "18",
   "ApiKey": {
-   "$id": "23",
+   "$id": "19",
    "Name": "Authorization",
    "Prefix": "SharedAccessKey"
   }
diff --git a/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/oauth2/tspCodeModel.json b/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/oauth2/tspCodeModel.json
index d2fed49fd0..40bd57d8d5 100644
--- a/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/oauth2/tspCodeModel.json
+++ b/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/oauth2/tspCodeModel.json
@@ -41,9 +41,8 @@
      "Parameters": [
       {
        "$id": "7",
-       "Name": "host",
-       "NameInRequest": "host",
-       "Description": "TestServer endpoint",
+       "Name": "endpoint",
+       "NameInRequest": "endpoint",
        "Type": {
         "$id": "8",
         "Kind": "string"
@@ -65,36 +64,11 @@
         },
         "Value": "http://localhost:3000"
        }
-      },
-      {
-       "$id": "11",
-       "Name": "accept",
-       "NameInRequest": "Accept",
-       "Type": {
-        "$id": "12",
-        "Kind": "string"
-       },
-       "Location": "Header",
-       "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
-       "IsRequired": true,
-       "IsEndpoint": false,
-       "SkipUrlEncoding": false,
-       "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "13",
-        "Type": {
-         "$ref": "12"
-        },
-        "Value": "application/json"
-       }
       }
      ],
      "Responses": [
       {
-       "$id": "14",
+       "$id": "11",
        "StatusCodes": [
         204
        ],
@@ -105,14 +79,14 @@
      ],
      "HttpMethod": "GET",
      "RequestBodyMediaType": "None",
-     "Uri": "{host}",
+     "Uri": "{endpoint}",
      "Path": "/authentication/oauth2/valid",
      "BufferResponse": true,
      "GenerateProtocolMethod": true,
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "15",
+     "$id": "12",
      "Name": "invalid",
      "ResourceName": "OAuth2",
      "Description": "Check whether client is authenticated. Will return an invalid bearer error.",
@@ -122,60 +96,41 @@
        "$ref": "7"
       },
       {
-       "$id": "16",
+       "$id": "13",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "17",
-        "Kind": "string"
+        "$id": "14",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "15",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "18",
-        "Type": {
-         "$ref": "17"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       }
      ],
      "Responses": [
       {
-       "$id": "19",
+       "$id": "16",
        "StatusCodes": [
         204
        ],
        "BodyMediaType": "Json",
        "Headers": [],
        "IsErrorResponse": false
-      },
-      {
-       "$id": "20",
-       "StatusCodes": [
-        403
-       ],
-       "BodyType": {
-        "$ref": "2"
-       },
-       "BodyMediaType": "Json",
-       "Headers": [],
-       "IsErrorResponse": true,
-       "ContentTypes": [
-        "application/json"
-       ]
       }
      ],
      "HttpMethod": "GET",
      "RequestBodyMediaType": "None",
-     "Uri": "{host}",
+     "Uri": "{endpoint}",
      "Path": "/authentication/oauth2/invalid",
      "BufferResponse": true,
      "GenerateProtocolMethod": true,
@@ -183,7 +138,7 @@
     }
    ],
    "Protocol": {
-    "$id": "21"
+    "$id": "17"
    },
    "Parameters": [
     {
@@ -193,9 +148,9 @@
   }
  ],
  "Auth": {
-  "$id": "22",
+  "$id": "18",
   "OAuth2": {
-   "$id": "23",
+   "$id": "19",
    "Scopes": [
     "https://security.microsoft.com/.default"
    ]
diff --git a/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/union/tspCodeModel.json b/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/union/tspCodeModel.json
index 2126391d3b..dc046df299 100644
--- a/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/union/tspCodeModel.json
+++ b/packages/http-client-csharp/generator/TestProjects/CadlRanch/http/authentication/union/tspCodeModel.json
@@ -19,9 +19,8 @@
      "Parameters": [
       {
        "$id": "4",
-       "Name": "host",
-       "NameInRequest": "host",
-       "Description": "TestServer endpoint",
+       "Name": "endpoint",
+       "NameInRequest": "endpoint",
        "Type": {
         "$id": "5",
         "Kind": "string"
@@ -43,36 +42,11 @@
         },
         "Value": "http://localhost:3000"
        }
-      },
-      {
-       "$id": "8",
-       "Name": "accept",
-       "NameInRequest": "Accept",
-       "Type": {
-        "$id": "9",
-        "Kind": "string"
-       },
-       "Location": "Header",
-       "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
-       "IsRequired": true,
-       "IsEndpoint": false,
-       "SkipUrlEncoding": false,
-       "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "10",
-        "Type": {
-         "$ref": "9"
-        },
-        "Value": "application/json"
-       }
       }
      ],
      "Responses": [
       {
-       "$id": "11",
+       "$id": "8",
        "StatusCodes": [
         204
        ],
@@ -83,14 +57,14 @@
      ],
      "HttpMethod": "GET",
      "RequestBodyMediaType": "None",
-     "Uri": "{host}",
+     "Uri": "{endpoint}",
      "Path": "/authentication/union/validkey",
      "BufferResponse": true,
      "GenerateProtocolMethod": true,
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "12",
+     "$id": "9",
      "Name": "validToken",
      "ResourceName": "Union",
      "Description": "Check whether client is authenticated",
@@ -98,36 +72,11 @@
      "Parameters": [
       {
        "$ref": "4"
-      },
-      {
-       "$id": "13",
-       "Name": "accept",
-       "NameInRequest": "Accept",
-       "Type": {
-        "$id": "14",
-        "Kind": "string"
-       },
-       "Location": "Header",
-       "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
-       "IsRequired": true,
-       "IsEndpoint": false,
-       "SkipUrlEncoding": false,
-       "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "15",
-        "Type": {
-         "$ref": "14"
-        },
-        "Value": "application/json"
-       }
       }
      ],
      "Responses": [
       {
-       "$id": "16",
+       "$id": "10",
        "StatusCodes": [
         204
        ],
@@ -138,7 +87,7 @@
      ],
      "HttpMethod": "GET",
      "RequestBodyMediaType": "None",
-     "Uri": "{host}",
+     "Uri": "{endpoint}",
      "Path": "/authentication/union/validtoken",
      "BufferResponse": true,
      "GenerateProtocolMethod": true,
@@ -146,7 +95,7 @@
     }
    ],
    "Protocol": {
-    "$id": "17"
+    "$id": "11"
    },
    "Parameters": [
     {
@@ -156,13 +105,13 @@
   }
  ],
  "Auth": {
-  "$id": "18",
+  "$id": "12",
   "ApiKey": {
-   "$id": "19",
+   "$id": "13",
    "Name": "x-ms-api-key"
   },
   "OAuth2": {
-   "$id": "20",
+   "$id": "14",
    "Scopes": [
     "https://security.microsoft.com/.default"
    ]
diff --git a/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/src/Generated/UnbrandedTypeSpecClient.RestClient.cs b/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/src/Generated/UnbrandedTypeSpecClient.RestClient.cs
index b2ac019e6d..585535af4d 100644
--- a/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/src/Generated/UnbrandedTypeSpecClient.RestClient.cs
+++ b/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/src/Generated/UnbrandedTypeSpecClient.RestClient.cs
@@ -75,8 +75,8 @@ internal PipelineMessage CreateNoContentTypeRequest(string p1, string p2, Binary
             uri.AppendPath(p2, true);
             request.Uri = uri.ToUri();
             request.Headers.Set("p1", p1);
-            request.Headers.Set("Accept", "application/json");
             request.Headers.Set("Content-Type", "application/json");
+            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
@@ -106,8 +106,8 @@ internal PipelineMessage CreateCreateLiteralRequest(BinaryContent content, Reque
             uri.Reset(_endpoint);
             uri.AppendPath("/literal", false);
             request.Uri = uri.ToUri();
-            request.Headers.Set("Accept", "application/json");
             request.Headers.Set("Content-Type", "application/json");
+            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
@@ -171,8 +171,8 @@ internal PipelineMessage CreatePatchActionRequest(BinaryContent content, Request
             uri.Reset(_endpoint);
             uri.AppendPath("/patch", false);
             request.Uri = uri.ToUri();
-            request.Headers.Set("Accept", "application/json");
             request.Headers.Set("Content-Type", "application/json");
+            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
@@ -187,8 +187,8 @@ internal PipelineMessage CreateAnonymousBodyRequest(RequestOptions options)
             uri.Reset(_endpoint);
             uri.AppendPath("/anonymousBody", false);
             request.Uri = uri.ToUri();
-            request.Headers.Set("Accept", "application/json");
             request.Headers.Set("Content-Type", "application/json");
+            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
@@ -203,8 +203,8 @@ internal PipelineMessage CreateFriendlyModelRequest(RequestOptions options)
             uri.Reset(_endpoint);
             uri.AppendPath("/friendlyName", false);
             request.Uri = uri.ToUri();
-            request.Headers.Set("Accept", "application/json");
             request.Headers.Set("Content-Type", "application/json");
+            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
@@ -220,7 +220,6 @@ internal PipelineMessage CreateAddTimeHeaderRequest(DateTimeOffset repeatability
             uri.AppendPath("/", false);
             request.Uri = uri.ToUri();
             request.Headers.Set("Repeatability-First-Sent", repeatabilityFirstSent.ToString("R"));
-            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
@@ -235,8 +234,8 @@ internal PipelineMessage CreateProjectedNameModelRequest(RequestOptions options)
             uri.Reset(_endpoint);
             uri.AppendPath("/projectedName", false);
             request.Uri = uri.ToUri();
-            request.Headers.Set("Accept", "application/json");
             request.Headers.Set("Content-Type", "application/json");
+            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
@@ -256,7 +255,7 @@ internal PipelineMessage CreateReturnsAnonymousModelRequest(RequestOptions optio
             return message;
         }
 
-        internal PipelineMessage CreateGetUnknownValueRequest(RequestOptions options)
+        internal PipelineMessage CreateGetUnknownValueRequest(string accept, RequestOptions options)
         {
             PipelineMessage message = Pipeline.CreateMessage();
             message.ResponseClassifier = PipelineMessageClassifier200;
@@ -266,7 +265,7 @@ internal PipelineMessage CreateGetUnknownValueRequest(RequestOptions options)
             uri.Reset(_endpoint);
             uri.AppendPath("/unknown-value", false);
             request.Uri = uri.ToUri();
-            request.Headers.Set("Accept", "application/json");
+            request.Headers.Set("Accept", accept);
             message.Apply(options);
             return message;
         }
@@ -281,8 +280,8 @@ internal PipelineMessage CreateInternalProtocolRequest(BinaryContent content, Re
             uri.Reset(_endpoint);
             uri.AppendPath("/internalProtocol", false);
             request.Uri = uri.ToUri();
-            request.Headers.Set("Accept", "application/json");
             request.Headers.Set("Content-Type", "application/json");
+            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
@@ -297,7 +296,6 @@ internal PipelineMessage CreateStillConvenientRequest(RequestOptions options)
             uri.Reset(_endpoint);
             uri.AppendPath("/stillConvenient", false);
             request.Uri = uri.ToUri();
-            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
@@ -313,7 +311,6 @@ internal PipelineMessage CreateHeadAsBooleanRequest(string id, RequestOptions op
             uri.AppendPath("/headAsBoolean/", false);
             uri.AppendPath(id, true);
             request.Uri = uri.ToUri();
-            request.Headers.Set("Accept", "application/json");
             message.Apply(options);
             return message;
         }
diff --git a/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/src/Generated/UnbrandedTypeSpecClient.cs b/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/src/Generated/UnbrandedTypeSpecClient.cs
index e6c54bf666..217631cb21 100644
--- a/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/src/Generated/UnbrandedTypeSpecClient.cs
+++ b/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/src/Generated/UnbrandedTypeSpecClient.cs
@@ -885,12 +885,16 @@ public virtual async Task<ClientResult<ReturnsAnonymousModelResponse>> ReturnsAn
         /// </item>
         /// </list>
         /// </summary>
+        /// <param name="accept"></param>
         /// <param name="options"> The request options, which can override default behaviors of the client pipeline on a per-call basis. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="accept"/> is null. </exception>
         /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
         /// <returns> The response returned from the service. </returns>
-        public virtual ClientResult GetUnknownValue(RequestOptions options)
+        public virtual ClientResult GetUnknownValue(string accept, RequestOptions options)
         {
-            using PipelineMessage message = CreateGetUnknownValueRequest(options);
+            Argument.AssertNotNull(accept, nameof(accept));
+
+            using PipelineMessage message = CreateGetUnknownValueRequest(accept, options);
             return ClientResult.FromResponse(Pipeline.ProcessMessage(message, options));
         }
 
@@ -902,28 +906,40 @@ public virtual ClientResult GetUnknownValue(RequestOptions options)
         /// </item>
         /// </list>
         /// </summary>
+        /// <param name="accept"></param>
         /// <param name="options"> The request options, which can override default behaviors of the client pipeline on a per-call basis. </param>
+        /// <exception cref="ArgumentNullException"> <paramref name="accept"/> is null. </exception>
         /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
         /// <returns> The response returned from the service. </returns>
-        public virtual async Task<ClientResult> GetUnknownValueAsync(RequestOptions options)
+        public virtual async Task<ClientResult> GetUnknownValueAsync(string accept, RequestOptions options)
         {
-            using PipelineMessage message = CreateGetUnknownValueRequest(options);
+            Argument.AssertNotNull(accept, nameof(accept));
+
+            using PipelineMessage message = CreateGetUnknownValueRequest(accept, options);
             return ClientResult.FromResponse(await Pipeline.ProcessMessageAsync(message, options).ConfigureAwait(false));
         }
 
         /// <summary> get extensible enum. </summary>
+        /// <param name="accept"></param>
+        /// <exception cref="ArgumentNullException"> <paramref name="accept"/> is null. </exception>
         /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
-        public virtual ClientResult<string> GetUnknownValue()
+        public virtual ClientResult<string> GetUnknownValue(string accept)
         {
-            ClientResult result = GetUnknownValue(null);
+            Argument.AssertNotNull(accept, nameof(accept));
+
+            ClientResult result = GetUnknownValue(accept, null);
             return ClientResult.FromValue(result.GetRawResponse().Content.ToString(), result.GetRawResponse());
         }
 
         /// <summary> get extensible enum. </summary>
+        /// <param name="accept"></param>
+        /// <exception cref="ArgumentNullException"> <paramref name="accept"/> is null. </exception>
         /// <exception cref="ClientResultException"> Service returned a non-success status code. </exception>
-        public virtual async Task<ClientResult<string>> GetUnknownValueAsync()
+        public virtual async Task<ClientResult<string>> GetUnknownValueAsync(string accept)
         {
-            ClientResult result = await GetUnknownValueAsync(null).ConfigureAwait(false);
+            Argument.AssertNotNull(accept, nameof(accept));
+
+            ClientResult result = await GetUnknownValueAsync(accept, null).ConfigureAwait(false);
             return ClientResult.FromValue(result.GetRawResponse().Content.ToString(), result.GetRawResponse());
         }
 
diff --git a/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/tspCodeModel.json b/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/tspCodeModel.json
index 71c5947d1b..5cf777b9e3 100644
--- a/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/tspCodeModel.json
+++ b/packages/http-client-csharp/generator/TestProjects/Local/Unbranded-TypeSpec/tspCodeModel.json
@@ -1502,7 +1502,7 @@
        "NameInRequest": "unbrandedTypeSpecUrl",
        "Type": {
         "$id": "225",
-        "Kind": "url"
+        "Kind": "uri"
        },
        "Location": "Uri",
        "IsApiVersion": false,
@@ -1523,13 +1523,11 @@
         "Kind": "string"
        },
        "Location": "Header",
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Method"
       },
       {
@@ -1541,13 +1539,11 @@
         "Kind": "string"
        },
        "Location": "Query",
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Method"
       },
       {
@@ -1559,13 +1555,11 @@
         "Kind": "string"
        },
        "Location": "Query",
-       "IsRequired": false,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": false,
        "Kind": "Method"
       },
       {
@@ -1574,24 +1568,20 @@
        "NameInRequest": "Accept",
        "Type": {
         "$id": "233",
-        "Kind": "string"
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "234",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "234",
-        "Type": {
-         "$ref": "233"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       }
      ],
      "Responses": [
@@ -1638,13 +1628,11 @@
         "Kind": "string"
        },
        "Location": "Header",
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Method"
       },
       {
@@ -1661,86 +1649,69 @@
         "Value": "text/plain"
        },
        "Location": "Header",
-       "DefaultValue": {
-        "$id": "242",
-        "Type": {
-         "$ref": "240"
-        },
-        "Value": "text/plain"
-       },
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Constant"
       },
       {
-       "$id": "243",
+       "$id": "242",
        "Name": "p2",
        "NameInRequest": "p2",
        "Type": {
-        "$id": "244",
+        "$id": "243",
         "Kind": "string"
        },
        "Location": "Path",
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Method"
       },
       {
-       "$id": "245",
-       "Name": "action",
-       "NameInRequest": "action",
+       "$id": "244",
+       "Name": "accept",
+       "NameInRequest": "Accept",
        "Type": {
-        "$ref": "115"
+        "$id": "245",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "246",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
-       "Location": "Body",
-       "IsRequired": true,
+       "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Method"
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "246",
-       "Name": "accept",
-       "NameInRequest": "Accept",
+       "$id": "247",
+       "Name": "action",
+       "NameInRequest": "action",
        "Type": {
-        "$id": "247",
-        "Kind": "string"
+        "$ref": "115"
        },
-       "Location": "Header",
+       "Location": "Body",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "248",
-        "Type": {
-         "$ref": "247"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Method"
       }
      ],
      "Responses": [
       {
-       "$id": "249",
+       "$id": "248",
        "StatusCodes": [
         200
        ],
@@ -1767,7 +1738,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "250",
+     "$id": "249",
      "Name": "noContentType",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "Return hi again",
@@ -1777,112 +1748,99 @@
        "$ref": "224"
       },
       {
-       "$id": "251",
+       "$id": "250",
        "Name": "p1",
        "NameInRequest": "p1",
        "Type": {
-        "$id": "252",
+        "$id": "251",
         "Kind": "string"
        },
        "Location": "Header",
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Method"
       },
       {
-       "$id": "253",
+       "$id": "252",
        "Name": "p2",
        "NameInRequest": "p2",
        "Type": {
-        "$id": "254",
+        "$id": "253",
         "Kind": "string"
        },
        "Location": "Path",
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Method"
       },
       {
-       "$id": "255",
-       "Name": "action",
-       "NameInRequest": "action",
+       "$id": "254",
+       "Name": "contentType",
+       "NameInRequest": "Content-Type",
+       "Description": "Body parameter's content type. Known values are application/json",
        "Type": {
-        "$ref": "115"
+        "$id": "255",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "256",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
-       "Location": "Body",
-       "IsRequired": true,
+       "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
+       "IsContentType": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Method"
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "256",
+       "$id": "257",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "257",
-        "Kind": "string"
+        "$id": "258",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "259",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "258",
-        "Type": {
-         "$ref": "257"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "259",
-       "Name": "contentType",
-       "NameInRequest": "Content-Type",
+       "$id": "260",
+       "Name": "action",
+       "NameInRequest": "action",
        "Type": {
-        "$id": "260",
-        "Kind": "string"
+        "$ref": "115"
        },
-       "Location": "Header",
+       "Location": "Body",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": true,
-       "IsRequired": true,
+       "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "261",
-        "Type": {
-         "$ref": "260"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Method"
       }
      ],
      "Responses": [
       {
-       "$id": "262",
+       "$id": "261",
        "StatusCodes": [
         200
        ],
@@ -1909,7 +1867,7 @@
      "GenerateConvenienceMethod": false
     },
     {
-     "$id": "263",
+     "$id": "262",
      "Name": "helloDemo2",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "Return hi in demo2",
@@ -1919,34 +1877,30 @@
        "$ref": "224"
       },
       {
-       "$id": "264",
+       "$id": "263",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "265",
-        "Kind": "string"
+        "$id": "264",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "265",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "266",
-        "Type": {
-         "$ref": "265"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       }
      ],
      "Responses": [
       {
-       "$id": "267",
+       "$id": "266",
        "StatusCodes": [
         200
        ],
@@ -1970,7 +1924,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "268",
+     "$id": "267",
      "Name": "createLiteral",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "Create with literal value",
@@ -1980,76 +1934,67 @@
        "$ref": "224"
       },
       {
-       "$id": "269",
-       "Name": "body",
-       "NameInRequest": "body",
+       "$id": "268",
+       "Name": "contentType",
+       "NameInRequest": "Content-Type",
+       "Description": "Body parameter's content type. Known values are application/json",
        "Type": {
-        "$ref": "78"
+        "$id": "269",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "270",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
-       "Location": "Body",
-       "IsRequired": true,
+       "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
+       "IsContentType": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Method"
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "270",
+       "$id": "271",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "271",
-        "Kind": "string"
+        "$id": "272",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "273",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "272",
-        "Type": {
-         "$ref": "271"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "273",
-       "Name": "contentType",
-       "NameInRequest": "Content-Type",
+       "$id": "274",
+       "Name": "body",
+       "NameInRequest": "body",
        "Type": {
-        "$id": "274",
-        "Kind": "string"
+        "$ref": "78"
        },
-       "Location": "Header",
+       "Location": "Body",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": true,
-       "IsRequired": true,
+       "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "275",
-        "Type": {
-         "$ref": "274"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Method"
       }
      ],
      "Responses": [
       {
-       "$id": "276",
+       "$id": "275",
        "StatusCodes": [
         200
        ],
@@ -2076,7 +2021,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "277",
+     "$id": "276",
      "Name": "helloLiteral",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "Send literal parameters",
@@ -2086,124 +2031,93 @@
        "$ref": "224"
       },
       {
-       "$id": "278",
+       "$id": "277",
        "Name": "p1",
        "NameInRequest": "p1",
        "Type": {
-        "$id": "279",
+        "$id": "278",
         "Kind": "constant",
         "ValueType": {
-         "$id": "280",
+         "$id": "279",
          "Kind": "string"
         },
         "Value": "test"
        },
        "Location": "Header",
-       "DefaultValue": {
-        "$id": "281",
-        "Type": {
-         "$ref": "279"
-        },
-        "Value": "test"
-       },
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Constant"
       },
       {
-       "$id": "282",
+       "$id": "280",
        "Name": "p2",
        "NameInRequest": "p2",
        "Type": {
-        "$id": "283",
+        "$id": "281",
         "Kind": "constant",
         "ValueType": {
-         "$id": "284",
+         "$id": "282",
          "Kind": "int32"
         },
         "Value": 123
        },
        "Location": "Path",
-       "DefaultValue": {
-        "$id": "285",
-        "Type": {
-         "$ref": "283"
-        },
-        "Value": 123
-       },
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Constant"
       },
       {
-       "$id": "286",
+       "$id": "283",
        "Name": "p3",
        "NameInRequest": "p3",
        "Type": {
-        "$id": "287",
+        "$id": "284",
         "Kind": "constant",
         "ValueType": {
-         "$id": "288",
+         "$id": "285",
          "Kind": "boolean"
         },
         "Value": true
        },
        "Location": "Query",
-       "DefaultValue": {
-        "$id": "289",
-        "Type": {
-         "$ref": "287"
-        },
-        "Value": true
-       },
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Constant"
       },
       {
-       "$id": "290",
+       "$id": "286",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "291",
-        "Kind": "string"
+        "$id": "287",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "288",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "292",
-        "Type": {
-         "$ref": "291"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       }
      ],
      "Responses": [
       {
-       "$id": "293",
+       "$id": "289",
        "StatusCodes": [
         200
        ],
@@ -2227,7 +2141,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "294",
+     "$id": "290",
      "Name": "topAction",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "top level method",
@@ -2237,57 +2151,51 @@
        "$ref": "224"
       },
       {
-       "$id": "295",
+       "$id": "291",
        "Name": "action",
        "NameInRequest": "action",
        "Type": {
-        "$id": "296",
+        "$id": "292",
         "Kind": "utcDateTime",
         "Encode": "rfc3339",
         "WireType": {
-         "$id": "297",
+         "$id": "293",
          "Kind": "string"
         }
        },
        "Location": "Path",
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": true,
        "Kind": "Method"
       },
       {
-       "$id": "298",
+       "$id": "294",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "299",
-        "Kind": "string"
+        "$id": "295",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "296",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "300",
-        "Type": {
-         "$ref": "299"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       }
      ],
      "Responses": [
       {
-       "$id": "301",
+       "$id": "297",
        "StatusCodes": [
         200
        ],
@@ -2311,7 +2219,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "302",
+     "$id": "298",
      "Name": "topAction2",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "top level method2",
@@ -2321,34 +2229,30 @@
        "$ref": "224"
       },
       {
-       "$id": "303",
+       "$id": "299",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "304",
-        "Kind": "string"
+        "$id": "300",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "301",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "305",
-        "Type": {
-         "$ref": "304"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       }
      ],
      "Responses": [
       {
-       "$id": "306",
+       "$id": "302",
        "StatusCodes": [
         200
        ],
@@ -2372,7 +2276,7 @@
      "GenerateConvenienceMethod": false
     },
     {
-     "$id": "307",
+     "$id": "303",
      "Name": "patchAction",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "top level patch",
@@ -2382,76 +2286,67 @@
        "$ref": "224"
       },
       {
-       "$id": "308",
-       "Name": "body",
-       "NameInRequest": "body",
+       "$id": "304",
+       "Name": "contentType",
+       "NameInRequest": "Content-Type",
+       "Description": "Body parameter's content type. Known values are application/json",
        "Type": {
-        "$ref": "78"
+        "$id": "305",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "306",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
-       "Location": "Body",
-       "IsRequired": true,
+       "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
+       "IsContentType": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Method"
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "309",
+       "$id": "307",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "310",
-        "Kind": "string"
+        "$id": "308",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "309",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "311",
-        "Type": {
-         "$ref": "310"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "312",
-       "Name": "contentType",
-       "NameInRequest": "Content-Type",
+       "$id": "310",
+       "Name": "body",
+       "NameInRequest": "body",
        "Type": {
-        "$id": "313",
-        "Kind": "string"
+        "$ref": "78"
        },
-       "Location": "Header",
+       "Location": "Body",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": true,
-       "IsRequired": true,
+       "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "314",
-        "Type": {
-         "$ref": "313"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Method"
       }
      ],
      "Responses": [
       {
-       "$id": "315",
+       "$id": "311",
        "StatusCodes": [
         200
        ],
@@ -2478,7 +2373,7 @@
      "GenerateConvenienceMethod": false
     },
     {
-     "$id": "316",
+     "$id": "312",
      "Name": "anonymousBody",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "body parameter without body decorator",
@@ -2488,76 +2383,67 @@
        "$ref": "224"
       },
       {
-       "$id": "317",
-       "Name": "AnonymousBodyRequest",
-       "NameInRequest": "",
+       "$id": "313",
+       "Name": "contentType",
+       "NameInRequest": "Content-Type",
+       "Description": "Body parameter's content type. Known values are application/json",
        "Type": {
-        "$ref": "172"
+        "$id": "314",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "315",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
-       "Location": "Body",
-       "IsRequired": true,
+       "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
+       "IsContentType": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Spread"
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "318",
+       "$id": "316",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "319",
-        "Kind": "string"
+        "$id": "317",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "318",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "320",
-        "Type": {
-         "$ref": "319"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "321",
-       "Name": "contentType",
-       "NameInRequest": "Content-Type",
+       "$id": "319",
+       "Name": "anonymousBodyRequest",
+       "NameInRequest": "anonymousBodyRequest",
        "Type": {
-        "$id": "322",
-        "Kind": "string"
+        "$ref": "172"
        },
-       "Location": "Header",
+       "Location": "Body",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": true,
-       "IsRequired": true,
+       "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "323",
-        "Type": {
-         "$ref": "322"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Spread"
       }
      ],
      "Responses": [
       {
-       "$id": "324",
+       "$id": "320",
        "StatusCodes": [
         200
        ],
@@ -2584,7 +2470,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "325",
+     "$id": "321",
      "Name": "friendlyModel",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "Model can have its friendly name",
@@ -2594,76 +2480,67 @@
        "$ref": "224"
       },
       {
-       "$id": "326",
-       "Name": "FriendlyModelRequest",
-       "NameInRequest": "",
+       "$id": "322",
+       "Name": "contentType",
+       "NameInRequest": "Content-Type",
+       "Description": "Body parameter's content type. Known values are application/json",
        "Type": {
-        "$ref": "209"
+        "$id": "323",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "324",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
-       "Location": "Body",
-       "IsRequired": true,
+       "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
+       "IsContentType": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Spread"
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "327",
+       "$id": "325",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "328",
-        "Kind": "string"
+        "$id": "326",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "327",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "329",
-        "Type": {
-         "$ref": "328"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "330",
-       "Name": "contentType",
-       "NameInRequest": "Content-Type",
+       "$id": "328",
+       "Name": "friendlyModelRequest",
+       "NameInRequest": "friendlyModelRequest",
        "Type": {
-        "$id": "331",
-        "Kind": "string"
+        "$ref": "209"
        },
-       "Location": "Header",
+       "Location": "Body",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": true,
-       "IsRequired": true,
+       "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "332",
-        "Type": {
-         "$ref": "331"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Spread"
       }
      ],
      "Responses": [
       {
-       "$id": "333",
+       "$id": "329",
        "StatusCodes": [
         200
        ],
@@ -2690,7 +2567,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "334",
+     "$id": "330",
      "Name": "addTimeHeader",
      "ResourceName": "UnbrandedTypeSpec",
      "Accessibility": "public",
@@ -2699,57 +2576,30 @@
        "$ref": "224"
       },
       {
-       "$id": "335",
+       "$id": "331",
        "Name": "repeatabilityFirstSent",
        "NameInRequest": "Repeatability-First-Sent",
        "Type": {
-        "$id": "336",
+        "$id": "332",
         "Kind": "utcDateTime",
         "Encode": "rfc7231",
         "WireType": {
-         "$id": "337",
+         "$id": "333",
          "Kind": "string"
         }
        },
        "Location": "Header",
-       "IsRequired": false,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
+       "IsRequired": false,
        "Kind": "Method"
-      },
-      {
-       "$id": "338",
-       "Name": "accept",
-       "NameInRequest": "Accept",
-       "Type": {
-        "$id": "339",
-        "Kind": "string"
-       },
-       "Location": "Header",
-       "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
-       "IsRequired": true,
-       "IsEndpoint": false,
-       "SkipUrlEncoding": false,
-       "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "340",
-        "Type": {
-         "$ref": "339"
-        },
-        "Value": "application/json"
-       }
       }
      ],
      "Responses": [
       {
-       "$id": "341",
+       "$id": "334",
        "StatusCodes": [
         204
        ],
@@ -2767,7 +2617,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "342",
+     "$id": "335",
      "Name": "projectedNameModel",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "Model can have its projected name",
@@ -2777,76 +2627,67 @@
        "$ref": "224"
       },
       {
-       "$id": "343",
-       "Name": "ProjectedNameModelRequest",
-       "NameInRequest": "",
+       "$id": "336",
+       "Name": "contentType",
+       "NameInRequest": "Content-Type",
+       "Description": "Body parameter's content type. Known values are application/json",
        "Type": {
-        "$ref": "215"
+        "$id": "337",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "338",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
-       "Location": "Body",
-       "IsRequired": true,
+       "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
+       "IsContentType": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Spread"
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "344",
+       "$id": "339",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "345",
-        "Kind": "string"
+        "$id": "340",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "341",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "346",
-        "Type": {
-         "$ref": "345"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "347",
-       "Name": "contentType",
-       "NameInRequest": "Content-Type",
+       "$id": "342",
+       "Name": "projectedNameModelRequest",
+       "NameInRequest": "projectedNameModelRequest",
        "Type": {
-        "$id": "348",
-        "Kind": "string"
+        "$ref": "215"
        },
-       "Location": "Header",
+       "Location": "Body",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": true,
-       "IsRequired": true,
+       "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "349",
-        "Type": {
-         "$ref": "348"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Spread"
       }
      ],
      "Responses": [
       {
-       "$id": "350",
+       "$id": "343",
        "StatusCodes": [
         200
        ],
@@ -2873,7 +2714,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "351",
+     "$id": "344",
      "Name": "returnsAnonymousModel",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "return anonymous model",
@@ -2883,34 +2724,30 @@
        "$ref": "224"
       },
       {
-       "$id": "352",
+       "$id": "345",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "353",
-        "Kind": "string"
+        "$id": "346",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "347",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "354",
-        "Type": {
-         "$ref": "353"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       }
      ],
      "Responses": [
       {
-       "$id": "355",
+       "$id": "348",
        "StatusCodes": [
         200
        ],
@@ -2934,7 +2771,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "356",
+     "$id": "349",
      "Name": "getUnknownValue",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "get extensible enum",
@@ -2944,45 +2781,48 @@
        "$ref": "224"
       },
       {
-       "$id": "357",
+       "$id": "350",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "358",
+        "$id": "351",
         "Kind": "string"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "359",
-        "Type": {
-         "$ref": "358"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Method"
       }
      ],
      "Responses": [
       {
-       "$id": "360",
+       "$id": "352",
        "StatusCodes": [
         200
        ],
        "BodyType": {
-        "$id": "361",
-        "Kind": "string"
+        "$id": "353",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "354",
+         "Kind": "string"
+        },
+        "Value": "Sunday"
        },
        "BodyMediaType": "Json",
        "Headers": [],
        "IsErrorResponse": false,
        "ContentTypes": [
+        "application/json",
+        "application/json",
+        "application/json",
+        "application/json",
+        "application/json",
+        "application/json",
+        "application/json",
         "application/json"
        ]
       }
@@ -2996,7 +2836,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "362",
+     "$id": "355",
      "Name": "internalProtocol",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "When set protocol false and convenient true, then the protocol method should be internal",
@@ -3006,76 +2846,67 @@
        "$ref": "224"
       },
       {
-       "$id": "363",
-       "Name": "body",
-       "NameInRequest": "body",
+       "$id": "356",
+       "Name": "contentType",
+       "NameInRequest": "Content-Type",
+       "Description": "Body parameter's content type. Known values are application/json",
        "Type": {
-        "$ref": "78"
+        "$id": "357",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "358",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
-       "Location": "Body",
-       "IsRequired": true,
+       "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
+       "IsContentType": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Method"
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "364",
+       "$id": "359",
        "Name": "accept",
        "NameInRequest": "Accept",
        "Type": {
-        "$id": "365",
-        "Kind": "string"
+        "$id": "360",
+        "Kind": "constant",
+        "ValueType": {
+         "$id": "361",
+         "Kind": "string"
+        },
+        "Value": "application/json"
        },
        "Location": "Header",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
-       "IsRequired": true,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "366",
-        "Type": {
-         "$ref": "365"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Constant"
       },
       {
-       "$id": "367",
-       "Name": "contentType",
-       "NameInRequest": "Content-Type",
+       "$id": "362",
+       "Name": "body",
+       "NameInRequest": "body",
        "Type": {
-        "$id": "368",
-        "Kind": "string"
+        "$ref": "78"
        },
-       "Location": "Header",
+       "Location": "Body",
        "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": true,
-       "IsRequired": true,
+       "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "369",
-        "Type": {
-         "$ref": "368"
-        },
-        "Value": "application/json"
-       }
+       "IsRequired": true,
+       "Kind": "Method"
       }
      ],
      "Responses": [
       {
-       "$id": "370",
+       "$id": "363",
        "StatusCodes": [
         200
        ],
@@ -3102,7 +2933,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "371",
+     "$id": "364",
      "Name": "stillConvenient",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "When set protocol false and convenient true, the convenient method should be generated even it has the same signature as protocol one",
@@ -3110,36 +2941,11 @@
      "Parameters": [
       {
        "$ref": "224"
-      },
-      {
-       "$id": "372",
-       "Name": "accept",
-       "NameInRequest": "Accept",
-       "Type": {
-        "$id": "373",
-        "Kind": "string"
-       },
-       "Location": "Header",
-       "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
-       "IsRequired": true,
-       "IsEndpoint": false,
-       "SkipUrlEncoding": false,
-       "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "374",
-        "Type": {
-         "$ref": "373"
-        },
-        "Value": "application/json"
-       }
       }
      ],
      "Responses": [
       {
-       "$id": "375",
+       "$id": "365",
        "StatusCodes": [
         204
        ],
@@ -3157,7 +2963,7 @@
      "GenerateConvenienceMethod": true
     },
     {
-     "$id": "376",
+     "$id": "366",
      "Name": "headAsBoolean",
      "ResourceName": "UnbrandedTypeSpec",
      "Description": "head as boolean.",
@@ -3167,52 +2973,25 @@
        "$ref": "224"
       },
       {
-       "$id": "377",
+       "$id": "367",
        "Name": "id",
        "NameInRequest": "id",
        "Type": {
-        "$id": "378",
+        "$id": "368",
         "Kind": "string"
        },
        "Location": "Path",
-       "IsRequired": true,
        "IsApiVersion": false,
-       "IsResourceParameter": false,
        "IsContentType": false,
        "IsEndpoint": false,
-       "SkipUrlEncoding": false,
        "Explode": false,
-       "Kind": "Method"
-      },
-      {
-       "$id": "379",
-       "Name": "accept",
-       "NameInRequest": "Accept",
-       "Type": {
-        "$id": "380",
-        "Kind": "string"
-       },
-       "Location": "Header",
-       "IsApiVersion": false,
-       "IsResourceParameter": false,
-       "IsContentType": false,
        "IsRequired": true,
-       "IsEndpoint": false,
-       "SkipUrlEncoding": false,
-       "Explode": false,
-       "Kind": "Constant",
-       "DefaultValue": {
-        "$id": "381",
-        "Type": {
-         "$ref": "380"
-        },
-        "Value": "application/json"
-       }
+       "Kind": "Method"
       }
      ],
      "Responses": [
       {
-       "$id": "382",
+       "$id": "369",
        "StatusCodes": [
         204
        ],
@@ -3231,7 +3010,7 @@
     }
    ],
    "Protocol": {
-    "$id": "383"
+    "$id": "370"
    },
    "Parameters": [
     {
@@ -3241,9 +3020,9 @@
   }
  ],
  "Auth": {
-  "$id": "384",
+  "$id": "371",
   "ApiKey": {
-   "$id": "385",
+   "$id": "372",
    "Name": "my-api-key"
   }
  }