diff --git a/src/base/Page.ts b/src/base/Page.ts
index 2230e4715..e2062e270 100644
--- a/src/base/Page.ts
+++ b/src/base/Page.ts
@@ -249,6 +249,8 @@ export default class Page<
     if (keys.length === 1) {
       return payload[keys[0]];
     }
+    for (const key of keys)
+      if (Array.isArray(payload[key])) return payload[key];
 
     throw new Error("Page Records cannot be deserialized");
   }
diff --git a/src/credential_provider/NoAuthCredentialProvider.ts b/src/credential_provider/NoAuthCredentialProvider.ts
index 337bd66a8..bd2415e5a 100644
--- a/src/credential_provider/NoAuthCredentialProvider.ts
+++ b/src/credential_provider/NoAuthCredentialProvider.ts
@@ -2,12 +2,16 @@ import CredentialProvider from "./CredentialProvider";
 import AuthStrategy from "../auth_strategy/AuthStrategy";
 import NoAuthStrategy from "../auth_strategy/NoAuthStrategy";
 
-export default class NoAuthCredentialProvider extends CredentialProvider {
-  constructor() {
-    super("client-credentials");
-  }
+namespace NoAuthCredentialProvider {
+  export class NoAuthCredentialProvider extends CredentialProvider {
+    constructor() {
+      super("client-credentials");
+    }
 
-  public toAuthStrategy(): AuthStrategy {
-    return new NoAuthStrategy();
+    public toAuthStrategy(): AuthStrategy {
+      return new NoAuthStrategy();
+    }
   }
 }
+
+export = NoAuthCredentialProvider;
diff --git a/src/http/bearer_token/ApiTokenManager.ts b/src/http/bearer_token/ApiTokenManager.ts
index afb7715b7..e16aadabe 100644
--- a/src/http/bearer_token/ApiTokenManager.ts
+++ b/src/http/bearer_token/ApiTokenManager.ts
@@ -16,7 +16,8 @@ export default class ApiTokenManager implements TokenManager {
   }
 
   async fetchToken(): Promise<string> {
-    const noAuthCredentialProvider = new NoAuthCredentialProvider();
+    const noAuthCredentialProvider =
+      new NoAuthCredentialProvider.NoAuthCredentialProvider();
     const client = new Client();
     client.setCredentialProvider(noAuthCredentialProvider);
 
diff --git a/src/index.ts b/src/index.ts
index c1d3a82dc..401c508d5 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -10,6 +10,7 @@ import IVoiceResponse from "./twiml/VoiceResponse";
 import IMessagingResponse from "./twiml/MessagingResponse";
 import IFaxResponse from "./twiml/FaxResponse";
 import IClientCredentialProvider from "./credential_provider/ClientCredentialProvider";
+import INoAuthCredentialProvider from "./credential_provider/NoAuthCredentialProvider";
 
 // Shorthand to automatically create a RestClient
 function TwilioSDK(
@@ -51,6 +52,11 @@ namespace TwilioSDK {
   export const ClientCredentialProviderBuilder =
     IClientCredentialProvider.ClientCredentialProviderBuilder;
 
+  export type NoAuthCredentialProvider =
+    INoAuthCredentialProvider.NoAuthCredentialProvider;
+  export const NoAuthCredentialProvider =
+    INoAuthCredentialProvider.NoAuthCredentialProvider;
+
   // Setup webhook helper functionality
   export type validateBody = typeof webhooks.validateBody;
   export const validateBody = webhooks.validateBody;
diff --git a/src/rest/previewIam/v1/authorize.ts b/src/rest/previewIam/v1/authorize.ts
index 0564f7808..df8915e79 100644
--- a/src/rest/previewIam/v1/authorize.ts
+++ b/src/rest/previewIam/v1/authorize.ts
@@ -103,6 +103,7 @@ export function AuthorizeListInstance(version: V1): AuthorizeListInstance {
     if (params["state"] !== undefined) data["state"] = params["state"];
 
     const headers: any = {};
+    headers["Accept"] = "application/json";
 
     let operationVersion = version,
       operationPromise = operationVersion.fetch({
diff --git a/src/rest/previewIam/v1/token.ts b/src/rest/previewIam/v1/token.ts
index d9ffc86ef..4e40089a4 100644
--- a/src/rest/previewIam/v1/token.ts
+++ b/src/rest/previewIam/v1/token.ts
@@ -107,6 +107,7 @@ export function TokenListInstance(version: V1): TokenListInstance {
 
     const headers: any = {};
     headers["Content-Type"] = "application/x-www-form-urlencoded";
+    headers["Accept"] = "application/json";
 
     let operationVersion = version,
       operationPromise = operationVersion.create({
diff --git a/src/rest/previewIam/versionless/organization/account.ts b/src/rest/previewIam/versionless/organization/account.ts
index da50fadaf..50db38f49 100644
--- a/src/rest/previewIam/versionless/organization/account.ts
+++ b/src/rest/previewIam/versionless/organization/account.ts
@@ -104,11 +104,15 @@ export class AccountContextImpl implements AccountContext {
   fetch(
     callback?: (error: Error | null, item?: AccountInstance) => any
   ): Promise<AccountInstance> {
+    const headers: any = {};
+    headers["Accept"] = "application/json";
+
     const instance = this;
     let operationVersion = instance._version,
       operationPromise = operationVersion.fetch({
         uri: instance._uri,
         method: "get",
+        headers,
       });
 
     operationPromise = operationPromise.then(
@@ -372,6 +376,7 @@ export function AccountListInstance(
     if (params.pageToken !== undefined) data["PageToken"] = params.pageToken;
 
     const headers: any = {};
+    headers["Accept"] = "application/json";
 
     let operationVersion = version,
       operationPromise = operationVersion.page({
diff --git a/src/rest/previewIam/versionless/organization/roleAssignment.ts b/src/rest/previewIam/versionless/organization/roleAssignment.ts
index 8ee251be3..8008dd8e3 100644
--- a/src/rest/previewIam/versionless/organization/roleAssignment.ts
+++ b/src/rest/previewIam/versionless/organization/roleAssignment.ts
@@ -141,11 +141,15 @@ export class RoleAssignmentContextImpl implements RoleAssignmentContext {
   remove(
     callback?: (error: Error | null, item?: boolean) => any
   ): Promise<boolean> {
+    const headers: any = {};
+    headers["Accept"] = "application/scim+json";
+
     const instance = this;
     let operationVersion = instance._version,
       operationPromise = operationVersion.remove({
         uri: instance._uri,
         method: "delete",
+        headers,
       });
 
     operationPromise = instance._version.setPromiseCallback(
@@ -309,7 +313,7 @@ export interface RoleAssignmentListInstance {
    */
   create(
     params: PublicApiCreateRoleAssignmentRequest,
-    headers: any,
+    headers?: any,
     callback?: (error: Error | null, item?: RoleAssignmentInstance) => any
   ): Promise<RoleAssignmentInstance>;
 
@@ -415,7 +419,7 @@ export function RoleAssignmentListInstance(
 
   instance.create = function create(
     params: PublicApiCreateRoleAssignmentRequest,
-    headers: any,
+    headers?: any,
     callback?: (error: Error | null, items: RoleAssignmentInstance) => any
   ): Promise<RoleAssignmentInstance> {
     if (params === null || params === undefined) {
@@ -426,7 +430,9 @@ export function RoleAssignmentListInstance(
 
     data = params;
 
-    headers["Content-Type"] = "application/json";
+    if (headers === null || headers === undefined) {
+      headers = {};
+    }
 
     let operationVersion = version,
       operationPromise = operationVersion.create({
@@ -475,6 +481,7 @@ export function RoleAssignmentListInstance(
     if (params.pageToken !== undefined) data["PageToken"] = params.pageToken;
 
     const headers: any = {};
+    headers["Accept"] = "application/json";
 
     let operationVersion = version,
       operationPromise = operationVersion.page({
diff --git a/src/rest/previewIam/versionless/organization/user.ts b/src/rest/previewIam/versionless/organization/user.ts
index 63805f326..0ca6ba3b7 100644
--- a/src/rest/previewIam/versionless/organization/user.ts
+++ b/src/rest/previewIam/versionless/organization/user.ts
@@ -222,7 +222,7 @@ export interface UserContext {
    */
   update(
     params: ScimUser,
-    headers: any,
+    headers?: any,
     callback?: (error: Error | null, item?: UserInstance) => any
   ): Promise<UserInstance>;
 
@@ -262,11 +262,15 @@ export class UserContextImpl implements UserContext {
   remove(
     callback?: (error: Error | null, item?: boolean) => any
   ): Promise<boolean> {
+    const headers: any = {};
+    headers["Accept"] = "application/scim+json";
+
     const instance = this;
     let operationVersion = instance._version,
       operationPromise = operationVersion.remove({
         uri: instance._uri,
         method: "delete",
+        headers,
       });
 
     operationPromise = instance._version.setPromiseCallback(
@@ -279,11 +283,15 @@ export class UserContextImpl implements UserContext {
   fetch(
     callback?: (error: Error | null, item?: UserInstance) => any
   ): Promise<UserInstance> {
+    const headers: any = {};
+    headers["Accept"] = "application/scim+json";
+
     const instance = this;
     let operationVersion = instance._version,
       operationPromise = operationVersion.fetch({
         uri: instance._uri,
         method: "get",
+        headers,
       });
 
     operationPromise = operationPromise.then(
@@ -305,7 +313,7 @@ export class UserContextImpl implements UserContext {
 
   update(
     params: ScimUser,
-    headers: any,
+    headers?: any,
     callback?: (error: Error | null, item?: UserInstance) => any
   ): Promise<UserInstance> {
     if (params === null || params === undefined) {
@@ -316,7 +324,9 @@ export class UserContextImpl implements UserContext {
 
     data = params;
 
-    headers["Content-Type"] = "application/json";
+    if (headers === null || headers === undefined) {
+      headers = {};
+    }
 
     const instance = this;
     let operationVersion = instance._version,
@@ -518,7 +528,7 @@ export class UserInstance {
    */
   update(
     params: ScimUser,
-    headers: any,
+    headers?: any,
     callback?: (error: Error | null, item?: UserInstance) => any
   ): Promise<UserInstance>;
 
@@ -583,7 +593,7 @@ export interface UserListInstance {
    */
   create(
     params: ScimUser,
-    headers: any,
+    headers?: any,
     callback?: (error: Error | null, item?: UserInstance) => any
   ): Promise<UserInstance>;
 
@@ -683,7 +693,7 @@ export function UserListInstance(
 
   instance.create = function create(
     params: ScimUser,
-    headers: any,
+    headers?: any,
     callback?: (error: Error | null, items: UserInstance) => any
   ): Promise<UserInstance> {
     if (params === null || params === undefined) {
@@ -694,7 +704,9 @@ export function UserListInstance(
 
     data = params;
 
-    headers["Content-Type"] = "application/json";
+    if (headers === null || headers === undefined) {
+      headers = {};
+    }
 
     let operationVersion = version,
       operationPromise = operationVersion.create({
@@ -741,6 +753,7 @@ export function UserListInstance(
     if (params.pageToken !== undefined) data["PageToken"] = params.pageToken;
 
     const headers: any = {};
+    headers["Accept"] = "application/scim+json";
 
     let operationVersion = version,
       operationPromise = operationVersion.page({