diff --git a/keyserver/src/creators/account-creator.js b/keyserver/src/creators/account-creator.js
--- a/keyserver/src/creators/account-creator.js
+++ b/keyserver/src/creators/account-creator.js
@@ -1,6 +1,7 @@
 // @flow
 
 import invariant from 'invariant';
+import { getRustAPI } from 'rust-node-addon';
 import bcrypt from 'twin-bcrypt';
 
 import ashoat from 'lib/facts/ashoat';
@@ -37,6 +38,7 @@
   fetchKnownUserInfos,
 } from '../fetchers/user-fetchers';
 import { verifyCalendarQueryThreadIDs } from '../responders/entry-responders';
+import { handleAsyncPromise } from '../responders/handlers';
 import { createNewUserCookie, setNewSession } from '../session/cookies';
 import { createScriptViewer } from '../session/scripts';
 import type { Viewer } from '../session/viewer';
@@ -180,11 +182,13 @@
     threadsResult,
     userInfos,
     currentUserInfo,
+    rustAPI,
   ] = await Promise.all([
     createMessages(viewer, messageDatas),
     fetchThreadInfos(viewer),
     fetchKnownUserInfos(viewer),
     fetchLoggedInUserInfo(viewer),
+    getRustAPI(),
   ]);
   const rawMessageInfos = [
     ...ashoatThreadResult.newMessageInfos,
@@ -192,6 +196,18 @@
     ...messageInfos,
   ];
 
+  const deviceID = request.deviceID ?? 'placeholder';
+  const userPublicKey = request.userPublicKey ?? 'placeholder';
+  handleAsyncPromise(
+    rustAPI.registerUser(
+      id,
+      deviceID,
+      request.username,
+      request.password,
+      userPublicKey,
+    ),
+  );
+
   return {
     id,
     rawMessageInfos,
diff --git a/lib/types/account-types.js b/lib/types/account-types.js
--- a/lib/types/account-types.js
+++ b/lib/types/account-types.js
@@ -51,6 +51,8 @@
   +calendarQuery?: ?CalendarQuery,
   +deviceTokenUpdateRequest?: ?DeviceTokenUpdateRequest,
   +platformDetails: PlatformDetails,
+  +deviceID?: ?string,
+  +userPublicKey?: ?string,
 };
 
 export type RegisterResponse = {