diff --git a/backend/src/routes/website-api/resolvers/login-resolver.ts b/backend/src/routes/website-api/resolvers/login-resolver.ts
index 361cc7a..13caac5 100644
--- a/backend/src/routes/website-api/resolvers/login-resolver.ts
+++ b/backend/src/routes/website-api/resolvers/login-resolver.ts
@@ -5,6 +5,7 @@ import _ from 'lodash';
 import {
   Arg, Ctx, Mutation, Resolver,
 } from 'type-graphql';
+import type { SerializedSDK } from '../../../types';
 import {
   encryptSymmetrical, encryptWithPublicKey, generatePrivatePublicPair, isObject, verifyCaptchaResponse,
 } from '../../../utils';
@@ -44,15 +45,22 @@ export default class LoginResolver {
       prompt.promptSecret,
     );
     const encryptedPassword = encryptWithPublicKey(password, publicKey);
-    console.log(diaryList.map((e) => e.serialized.info));
-    const students = _.toPairs(_.groupBy(diaryList.map((e) => e.serialized.info), 'studentId'))
+    const diaryStudents = _.groupBy(diaryList.map((e) => e.serialized.info), 'studentId');
+    const students = _.toPairs(diaryStudents)
       .map(([, diaryInfoList]: [string, DiaryInfo[]]) => diaryInfoList[0])
       .map<LoginResultStudent>((diaryInfo) => ({
       name: `${diaryInfo.studentFirstName} ${diaryInfo.studentSurname}`,
       studentId: diaryInfo.studentId,
     }));
+    const serializedSDK: SerializedSDK = {
+      client: client.serialize(),
+      diaries: diaryList.map(({ serialized }) => serialized),
+    };
+    const encryptedSDK = encryptWithPublicKey(JSON.stringify(serializedSDK), publicKey);
     prompt.loginInfo = {
       encryptedPassword,
+      encryptedSDK,
+      publicKey,
       host,
       username,
       availableStudentIds: students.map(({ studentId }) => studentId),
diff --git a/backend/src/types.ts b/backend/src/types.ts
index 1840cd1..8101df6 100644
--- a/backend/src/types.ts
+++ b/backend/src/types.ts
@@ -1,3 +1,5 @@
+import type { SerializedClient } from '@wulkanowy/sdk/dist/diary/interfaces/serialized-client';
+import type { SerializedDiary } from '@wulkanowy/sdk/dist/diary/interfaces/serialized-diary';
 import type {
   FastifyInstance,
   FastifyReply,
@@ -34,6 +36,8 @@ export interface Prompt {
     host: string;
     username: string;
     encryptedPassword: string;
+    encryptedSDK: string;
+    publicKey: string;
     availableStudentIds: number[];
   };
 }
@@ -46,6 +50,11 @@ export interface Session {
   data?: SessionData;
 }
 
+export interface SerializedSDK {
+  client: SerializedClient;
+  diaries: SerializedDiary[];
+}
+
 export type MyFastifyInstance = FastifyInstance<RawServerDefault, RawRequestDefaultExpression<RawServerDefault>, RawReplyDefaultExpression<RawServerDefault>>;
 
 export interface ApolloContext {
diff --git a/backend/src/utils/index.ts b/backend/src/utils/index.ts
index f902049..541915f 100644
--- a/backend/src/utils/index.ts
+++ b/backend/src/utils/index.ts
@@ -1,8 +1,10 @@
+import wulkanowy from '@wulkanowy/sdk';
+import type { GetCredentialsFunction } from '@wulkanowy/sdk/dist/client/types';
 import got from 'got';
 import _ from 'lodash';
 import { ParamError } from '../errors';
 import SessionData from '../session-data';
-import type { Session } from '../types';
+import type { SerializedSDK, Session } from '../types';
 
 export * from './crypto';
 
@@ -76,3 +78,23 @@ export async function verifyCaptchaResponse(response: string): Promise<boolean>
   console.log(body);
   return body.success;
 }
+
+export function sdkToJSON(client: wulkanowy.Client, diaries: wulkanowy.Diary[]): string {
+  const serialized: SerializedSDK = {
+    client: client.serialize(),
+    diaries: diaries.map((diary) => diary.serialize()),
+  };
+  return JSON.stringify(serialized);
+}
+
+export function sdkFromJSON(json: string, getCredentials: GetCredentialsFunction): {
+  client: wulkanowy.Client,
+  diaries: wulkanowy.Diary[]
+} {
+  const serialized = JSON.parse(json) as SerializedSDK;
+  const client = wulkanowy.Client.deserialize(serialized.client, getCredentials);
+  return {
+    client,
+    diaries: serialized.diaries.map((serializedDiary) => new wulkanowy.Diary(client, serializedDiary)),
+  };
+}