diff --git a/.idea/inspectionProfiles/Project_Default.xml b/.idea/inspectionProfiles/Project_Default.xml
index 03d9549..832ccb8 100644
--- a/.idea/inspectionProfiles/Project_Default.xml
+++ b/.idea/inspectionProfiles/Project_Default.xml
@@ -2,5 +2,6 @@
   <profile version="1.0">
     <option name="myName" value="Project Default" />
     <inspection_tool class="Eslint" enabled="true" level="WARNING" enabled_by_default="true" />
+    <inspection_tool class="ExceptionCaughtLocallyJS" enabled="true" level="WEAK WARNING" enabled_by_default="true" />
   </profile>
 </component>
\ No newline at end of file
diff --git a/backend/src/routes/oauth2/authorize.ts b/backend/src/routes/oauth2/authorize.ts
index d92cd78..a53089a 100644
--- a/backend/src/routes/oauth2/authorize.ts
+++ b/backend/src/routes/oauth2/authorize.ts
@@ -3,7 +3,8 @@ import { nanoid } from 'nanoid';
 import { scopes } from '../../constants';
 import database from '../../database/database';
 import { ParamError, ScopeError } from '../../errors';
-import type { MyFastifyInstance } from '../../types';
+import type { MyFastifyInstance, StudentsMode } from '../../types';
+
 import {
   getSessionData, isObject, parseScopeParam, validateOptionalParam, validateParam,
 } from '../../utils';
@@ -39,22 +40,30 @@ export default function registerAuthorize(server: MyFastifyInstance): void {
     try {
       validateParam('response_type', request.query.response_type);
       if (request.query.response_type === 'code') {
-        const requestedScopes = _.uniq(parseScopeParam('scope', request.query.scope));
-        requestedScopes.forEach((scope) => {
-          if (!scopes.includes(scope)) {
-            throw new ScopeError(`Unknown scope ${scope}`);
-          }
-        });
+        validateParam('students_mode', request.query.students_mode);
         validateOptionalParam('state', request.query.state);
         validateOptionalParam('code_challenge', request.query.code_challenge);
         validateOptionalParam('code_challenge_method', request.query.code_challenge_method);
 
         const codeChallengeMethod = request.query.code_challenge_method ?? 'plain';
         if (codeChallengeMethod !== 'plain' && codeChallengeMethod !== 'S256') {
-          await reply.redirect(`${request.query.redirect_uri}?error=invalid_request&error_description=${encodeURIComponent('code_challenge_method should be either plain or S256')}`);
-          return;
+          throw new ParamError('code_challenge_method should be either "plain" or "S256"');
         }
 
+        if (
+          !['none', 'one', 'many'].includes(request.query.students_mode)
+        ) {
+          throw new ParamError('students_mode should be either "none", "one" or "many"');
+        }
+        const studentsMode = request.query.students_mode as StudentsMode;
+
+        const requestedScopes = _.uniq(parseScopeParam('scope', request.query.scope));
+        requestedScopes.forEach((scope) => {
+          if (!scopes.includes(scope)) {
+            throw new ScopeError(`Unknown scope ${scope}`);
+          }
+        });
+
         const promptId = nanoid(12);
 
         const sessionData = getSessionData(request.session);
@@ -67,6 +76,7 @@ export default function registerAuthorize(server: MyFastifyInstance): void {
             method: codeChallengeMethod,
             value: request.query.code_challenge,
           },
+          studentsMode,
         });
 
         await reply.redirect(`/authenticate-prompt?prompt_id=${promptId}`);
diff --git a/backend/src/routes/website-api/models/prompt-info.ts b/backend/src/routes/website-api/models/prompt-info.ts
index 0fc787e..36898cb 100644
--- a/backend/src/routes/website-api/models/prompt-info.ts
+++ b/backend/src/routes/website-api/models/prompt-info.ts
@@ -1,4 +1,5 @@
 import { Field, ObjectType } from 'type-graphql';
+import { StudentsMode } from '../../../types';
 import PromptInfoApplication from './prompt-info-application';
 
 @ObjectType()
@@ -12,6 +13,9 @@ export default class PromptInfo {
   @Field(() => String)
   public clientId!: string;
 
+  @Field(() => StudentsMode)
+  public studentsMode!: StudentsMode;
+
   @Field(() => PromptInfoApplication)
   public application!: PromptInfoApplication;
 }
diff --git a/backend/src/routes/website-api/resolvers/prompt-info-resolver.ts b/backend/src/routes/website-api/resolvers/prompt-info-resolver.ts
index 96df930..962fb39 100644
--- a/backend/src/routes/website-api/resolvers/prompt-info-resolver.ts
+++ b/backend/src/routes/website-api/resolvers/prompt-info-resolver.ts
@@ -22,6 +22,7 @@ export default class PromptInfoResolver implements ResolverInterface<PromptInfo>
       id: promptId,
       clientId: prompt.clientId,
       scopes: prompt.scopes,
+      studentsMode: prompt.studentsMode,
     };
   }
 
diff --git a/backend/src/types.ts b/backend/src/types.ts
index c505fd4..753b14f 100644
--- a/backend/src/types.ts
+++ b/backend/src/types.ts
@@ -1,8 +1,19 @@
 import type {
   FastifyInstance, FastifyRequest, RawReplyDefaultExpression, RawRequestDefaultExpression, RawServerDefault,
 } from 'fastify';
+import { registerEnumType } from 'type-graphql';
 import type SessionData from './session-data';
 
+export enum StudentsMode {
+  None = 'none',
+  One = 'one',
+  Many = 'many',
+}
+
+registerEnumType(StudentsMode, {
+  name: 'StudentsMode',
+});
+
 export interface Prompt {
   clientId: string;
   redirectUri: string;
@@ -12,6 +23,7 @@ export interface Prompt {
     value: string;
     method: 'plain' | 'S256';
   };
+  studentsMode: StudentsMode;
   loginInfo?: {
     host: string;
     username: string;