diff --git a/keyserver/src/responders/website-responders.js b/keyserver/src/responders/website-responders.js
--- a/keyserver/src/responders/website-responders.js
+++ b/keyserver/src/responders/website-responders.js
@@ -511,6 +511,7 @@
           cookie: undefined,
           sessionID,
           updatesCurrentAsOf,
+          urlPrefix,
         },
       },
     };
diff --git a/lib/reducers/keyserver-reducer.js b/lib/reducers/keyserver-reducer.js
--- a/lib/reducers/keyserver-reducer.js
+++ b/lib/reducers/keyserver-reducer.js
@@ -14,6 +14,7 @@
 } from '../types/socket-types.js';
 import { processUpdatesActionType } from '../types/update-types.js';
 import { setNewSessionActionType } from '../utils/action-utils.js';
+import { setURLPrefix } from '../utils/url-utils.js';
 import { ashoatKeyserverID } from '../utils/validation-utils.js';
 
 export default function reduceKeyserverStore(
@@ -75,6 +76,17 @@
         },
       },
     };
+  } else if (action.type === setURLPrefix) {
+    return {
+      ...state,
+      keyserverInfos: {
+        ...state.keyserverInfos,
+        [ashoatKeyserverID]: {
+          ...state.keyserverInfos[ashoatKeyserverID],
+          urlPrefix: action.payload,
+        },
+      },
+    };
   }
 
   return state;
diff --git a/lib/types/keyserver-types.js b/lib/types/keyserver-types.js
--- a/lib/types/keyserver-types.js
+++ b/lib/types/keyserver-types.js
@@ -11,6 +11,7 @@
   +cookie?: ?string,
   +sessionID?: ?string,
   +updatesCurrentAsOf: number, // millisecond timestamp
+  +urlPrefix: string,
 };
 
 export type KeyserverStore = {
@@ -22,6 +23,7 @@
     cookie: t.maybe(t.String),
     sessionID: t.maybe(t.String),
     updatesCurrentAsOf: t.Number,
+    urlPrefix: t.String,
   });
 
 export const keyserverStoreValidator: TInterface<KeyserverStore> =
diff --git a/native/redux/redux-setup.js b/native/redux/redux-setup.js
--- a/native/redux/redux-setup.js
+++ b/native/redux/redux-setup.js
@@ -123,7 +123,10 @@
   lastCommunicatedPlatformDetails: {},
   keyserverStore: {
     keyserverInfos: {
-      [ashoatKeyserverID]: { updatesCurrentAsOf: 0 },
+      [ashoatKeyserverID]: {
+        updatesCurrentAsOf: 0,
+        urlPrefix: defaultURLPrefix,
+      },
     },
   },
 }: AppState);