diff --git a/src/Common/Constants.ts b/src/Common/Constants.ts
index cde5e9462..ce0042890 100644
--- a/src/Common/Constants.ts
+++ b/src/Common/Constants.ts
@@ -183,6 +183,12 @@ export class CassandraProxyAPIs {
   public static readonly connectionStringSchemaApi: string = "api/connectionstring/cassandra/schema";
 }
 
+export class AadEndpoints {
+  public static readonly Prod: string = "https://login.microsoftonline.com/";
+  public static readonly Fairfax: string = "https://login.microsoftonline.us/";
+  public static readonly Mooncake: string = "https://login.partner.microsoftonline.cn/";
+}
+
 export class Queries {
   public static CustomPageOption: string = "custom";
   public static UnlimitedPageOption: string = "unlimited";
diff --git a/src/ConfigContext.ts b/src/ConfigContext.ts
index 6d15a8a0f..5bf6c962b 100644
--- a/src/ConfigContext.ts
+++ b/src/ConfigContext.ts
@@ -5,6 +5,7 @@ import {
   MongoProxyEndpoints,
   PortalBackendEndpoints,
 } from "Common/Constants";
+import { userContext } from "UserContext";
 import {
   allowedAadEndpoints,
   allowedArcadiaEndpoints,
@@ -36,6 +37,7 @@ export interface ConfigContext {
   gitSha?: string;
   proxyPath?: string;
   AAD_ENDPOINT: string;
+  ENVIRONMENT: string;
   ARM_AUTH_AREA: string;
   ARM_ENDPOINT: string;
   EMULATOR_ENDPOINT?: string;
@@ -91,7 +93,7 @@ let configContext: Readonly<ConfigContext> = {
   ], // Webpack injects this at build time
   gitSha: process.env.GIT_SHA,
   hostedExplorerURL: "https://cosmos.azure.com/",
-  AAD_ENDPOINT: "https://login.microsoftonline.com/",
+  AAD_ENDPOINT: "",
   ARM_AUTH_AREA: "https://management.azure.com/",
   ARM_ENDPOINT: "https://management.azure.com/",
   ARM_API_VERSION: "2016-06-01",
diff --git a/src/Utils/EndpointUtils.ts b/src/Utils/EndpointUtils.ts
index b685dc71a..fb505a431 100644
--- a/src/Utils/EndpointUtils.ts
+++ b/src/Utils/EndpointUtils.ts
@@ -52,7 +52,10 @@ export const defaultAllowedArmEndpoints: ReadonlyArray<string> = [
   "https://management.chinacloudapi.cn",
 ];
 
-export const allowedAadEndpoints: ReadonlyArray<string> = ["https://login.microsoftonline.com/"];
+export const allowedAadEndpoints: ReadonlyArray<string> = ["https://login.microsoftonline.com/", 
+  "https://login.microsoftonline.us/",
+  "https://login.partner.microsoftonline.cn/"
+];
 
 export const defaultAllowedBackendEndpoints: ReadonlyArray<string> = [
   "https://main.documentdb.ext.azure.com",
diff --git a/src/hooks/useKnockoutExplorer.ts b/src/hooks/useKnockoutExplorer.ts
index ed7b762bc..0a8902777 100644
--- a/src/hooks/useKnockoutExplorer.ts
+++ b/src/hooks/useKnockoutExplorer.ts
@@ -639,6 +639,31 @@ function updateContextsFromPortalMessage(inputs: DataExplorerInputsFrame) {
     PORTAL_BACKEND_ENDPOINT: inputs.portalBackendEndpoint,
   });
 
+  const portalEnv = inputs.serverId as PortalEnv;
+
+  switch (portalEnv) {
+    case "prod1":
+    case "prod":
+      updateConfigContext({
+        AAD_ENDPOINT: Constants.AadEndpoints.Prod
+      });
+      break;
+    case "fairfax":
+      updateConfigContext({
+        AAD_ENDPOINT: Constants.AadEndpoints.Fairfax
+      });
+      break;  
+    case "mooncake":
+      updateConfigContext({
+        AAD_ENDPOINT: Constants.AadEndpoints.Mooncake
+      });
+      break;
+
+    default:
+      console.warn(`Unknown portal environment: ${portalEnv}`);
+      break;
+  }
+  
   updateUserContext({
     authorizationToken,
     databaseAccount,