diff --git a/access/serializers.py b/access/serializers.py
index a9d5c6f..2aea54b 100644
--- a/access/serializers.py
+++ b/access/serializers.py
@@ -1,10 +1,9 @@
 from django.contrib.auth import get_user_model
 from rest_framework import serializers
-from rest_framework.generics import get_object_or_404
 
 from access.models.other import Account
 from achievements.serialers import DiplomaSerializer, AchievementsSerializer
-from progress.serializers import ProgressSerializer
+from progress.serializers import SecureProgressSerializer
 
 
 class AccountSerializer(serializers.ModelSerializer):
@@ -22,13 +21,13 @@ class AccountSerializer(serializers.ModelSerializer):
 class UserSelfSerializer(serializers.ModelSerializer):
     account = serializers.SerializerMethodField()
     groups = serializers.SerializerMethodField()
-    progress = serializers.SerializerMethodField()
+    progresses = serializers.SerializerMethodField()
     diplomas = serializers.SerializerMethodField()
     achievements = serializers.SerializerMethodField()
 
     class Meta:
         model = get_user_model()
-        fields = ('out_key', 'email', 'first_name', 'last_name', 'progress', 'achievements',
+        fields = ('out_key', 'email', 'first_name', 'last_name', 'progresses', 'achievements',
                   'account', 'groups', 'is_staff', 'is_superuser', 'diplomas', 'is_active')
 
     @staticmethod
@@ -48,8 +47,8 @@ class UserSelfSerializer(serializers.ModelSerializer):
         return [group.name for group in self.groups.all()]
 
     @staticmethod
-    def get_progress(self):
-        return [ProgressSerializer(i).data for i in self.progress_set.all()]
+    def get_progresses(self):
+        return [SecureProgressSerializer(i).data for i in self.progress_set.all()]
 
 
 class UserProfileSerializer(serializers.ModelSerializer):
diff --git a/access/urls.py b/access/urls.py
index 579905d..f2961b6 100644
--- a/access/urls.py
+++ b/access/urls.py
@@ -18,10 +18,6 @@ urlpatterns = [
     url(r'logout/$', views.LogoutView.as_view()),
     url(r'reset/$', views.ResetPasswordView.as_view()),
     url(r'progress_detail/upload/(?P<token>[0-9A-Fa-f-]+)/$', progress.views.UploadCourseProgressUserView.as_view()),
-    url(
-        r'management/password/$',
-        views.ManagementPassword.as_view(),
-        name='management-password'
-        )
+    url(r'management/password/$', views.ManagementPassword.as_view(), name='management-password')
 
 ]
diff --git a/courses/models.py b/courses/models.py
index 7785b4c..3bc61ac 100755
--- a/courses/models.py
+++ b/courses/models.py
@@ -154,19 +154,26 @@ class Course(models.Model):
             lesson_list += list(topic.lesson_set.all())
         return lesson_list
 
-    def get_next(self, lesson: Lesson) -> Lesson:
+    def get_next(self, lesson: Lesson, f=None) -> Lesson:
         lessons = self.get_lesson_list()
         try:
-            return lessons[lessons.index(lesson)]
+            n = lessons[lessons.index(lesson)+1]
+            if f is None or f(n):
+                return n
+            else:
+                return self.get_next(n, f)
         except IndexError:
             pass
 
-    def get_previous(self, lesson: Lesson):
+    def get_previous(self, lesson: Lesson, f=None):
         lessons = self.get_lesson_list()
-        try:
-            return lessons[lessons.index(lesson) - 2]
-        except IndexError:
-            pass
+        idx = lessons.index(lesson) - 1
+        if idx > -1:
+            prev = lessons[idx]
+            if f is None or f(prev):
+                return prev
+            else:
+                return self.get_previous(prev, f)
 
     def get_first_lesson(self) -> Lesson:
         lessons = self.get_lesson_list()
diff --git a/courses/serializers.py b/courses/serializers.py
index 70e4ba6..359386b 100644
--- a/courses/serializers.py
+++ b/courses/serializers.py
@@ -23,11 +23,16 @@ class MiniLessonSerializer(serializers.ModelSerializer):
 
 
 class LessonSerializer(MiniLessonSerializer):
+    course_slug = serializers.SerializerMethodField()
 
     class Meta:
         model = Lesson
         exclude = ('id', 'topic', 'key')
 
+    @staticmethod
+    def get_course_slug(self):
+        return self.topic.course.slug
+
 
 class TeacherLessonSerializer(MiniLessonSerializer):
     topic_sort = serializers.SerializerMethodField()
diff --git a/courses/tasks.py b/courses/tasks.py
new file mode 100644
index 0000000..9384958
--- /dev/null
+++ b/courses/tasks.py
@@ -0,0 +1,13 @@
+from progress.models import ProgressLesson, Progress
+from django.contrib.auth import get_user_model
+
+
+def add_lesson(user_out_key: str, course_token: str, lesson_token: str, teacher_key: str, is_hm: bool):
+
+    p = Progress.objects.get(course_token=course_token, user__out_key=user_out_key)
+
+    ProgressLesson.objects.get_or_create(
+        progress=p,
+        lesson_token=lesson_token,
+        checker=get_user_model().objects.get(out_key=(teacher_key if is_hm else user_out_key)),
+    )
\ No newline at end of file
diff --git a/courses/urls.py b/courses/urls.py
index d30f49b..819f814 100644
--- a/courses/urls.py
+++ b/courses/urls.py
@@ -3,8 +3,8 @@ from django.conf.urls import url
 from courses import views as views
 
 urlpatterns = [
-    url(r'vertex/(?P<token>.+)/$', views.LessonDetail.as_view()),
     url(r'lesson/teacher/(?P<token>.+)/$', views.LessonInfoView.as_view()),
+    url(r'lesson/(?P<token>.+)/$', views.LessonDetail.as_view()),
     url(r'tree/(?P<slug>.+)/$', views.TreeView.as_view()),
     url(r'detail/(?P<slug>.+)/$', views.CourseDetailView.as_view()),
     url(r'^$', views.CourseListView.as_view()),
diff --git a/courses/views.py b/courses/views.py
index ea9536f..1a6138b 100644
--- a/courses/views.py
+++ b/courses/views.py
@@ -1,3 +1,5 @@
+from jwt import DecodeError
+
 from courses.models import Course, Lesson
 from rest_framework.renderers import JSONRenderer
 from rest_framework.response import Response
@@ -5,7 +7,10 @@ from rest_framework.views import APIView
 from django.contrib.auth import get_user_model
 
 from courses.serializers import CourseDetailSerializer, CourseTreeSerializer, LessonSerializer, TeacherLessonSerializer
-from progress.models import ProgressLesson
+import jwt
+
+from courses.tasks import add_lesson
+from lms import settings
 
 
 class TreeView(APIView):
@@ -93,33 +98,53 @@ class LessonDetail(APIView):
     renderer_classes = (JSONRenderer,)
 
     @staticmethod
-    def get(request, token):
+    def post(request, token):
+        jwt_token = request.JSON.get('jwt_token', None)
 
         try:
             lesson = Lesson.objects.get(token=token)
         except Lesson.DoesNotExist:
-            return Response("Lesson doesn't exist", status=404)
-
-        if not lesson.free and not ProgressLesson.objects.filter(lesson_token=lesson.token).exists():
-            previous_lesson = lesson.topic.course.get_previous(lesson)
-
-            if not previous_lesson is None or not ProgressLesson.objects.filter(
-                    lesson_token=previous_lesson.token, status=ProgressLesson.STATUSES.done).exists():
-                return Response("Lesson doesn't access", status=403)
-
-                # TODO: Доделать систему прав на курс
-
-        res = LessonSerializer(lesson).data
-        # progress = vertex.course.progress_set.filter(user=request.user)
-        # try:
-        #     if progress.exists():
-        #         next_vertex = vertex.get_next(progress[0].get_template())
-        #         if next_vertex:
-        #             res['next'] = MiniVertexSerializer(next_vertex).data
-        #         res['is_in_progress'] = vertex in progress[0].get_objects_in_progress()
-        #     else:
-        #         res['next'] = MiniVertexSerializer(vertex.get_next(vertex.course.route)).data
-        # except Thread.DoesNotExist or Vertex.DoesNotExist:
-        #     res['next'] = MiniVertexSerializer(vertex.get_next(vertex.course.route)).data
-
-        return Response(res, status=200)
+            return Response("Урока не существует", status=404)
+
+        l = LessonSerializer(lesson).data
+
+        try:
+            payload = None if jwt_token is None\
+                else jwt.decode(jwt_token, settings.COURSE_PROGRESS_SECRET_KEY, algorithms=['HS256'])
+        except DecodeError:
+            payload = None
+
+        course = lesson.topic.course
+
+        if payload is None:
+            if not lesson.free:
+                return Response("Bad token", status=400)
+
+            else:
+                return Response(l, status=200)
+
+        prev_lesson = course.get_previous(lesson, (lambda x: not x.is_hm) if payload['only_watch'] else None)
+        next_lesson = course.get_next(lesson, (lambda x: not x.is_hm) if payload['only_watch'] else None)
+
+        if not prev_lesson is None:
+            l['prev_token'] = prev_lesson.token
+
+        if not next_lesson is None:
+            l['next_token'] = next_lesson.token
+
+        new_lesson = False
+        for payload_lesson in payload['lessons']:
+            if payload_lesson['lesson_token'] == str(lesson.token):
+                return Response(l, status=200)
+
+            if not prev_lesson is None and str(prev_lesson.token) == payload_lesson['lesson_token']:
+                new_lesson = True if prev_lesson is None else \
+                    (payload_lesson['status'] == "done" or payload_lesson['status'] == "wait")
+
+        if not new_lesson:
+            return Response("Permission denied", status=403)
+
+        #TODO Задача для селери
+        add_lesson(request.user.out_key, course.token, lesson.token, course.get_teacher(), lesson.is_hm)
+
+        return Response(l, status=200)
diff --git a/finance/views.py b/finance/views.py
index ac08320..c97513f 100644
--- a/finance/views.py
+++ b/finance/views.py
@@ -295,4 +295,13 @@ class YandexFailView(APIView):
 
         logger_yandex.error(data)
 
-        return redirect(to=settings.DOMAIN)
\ No newline at end of file
+        return redirect(to=settings.DOMAIN)
+
+
+class DemoYandexCheckView(YandexCheckView):
+    """для тестирования платежей"""
+    pass
+
+
+class DemoYandexAvisoView(YandexAvisoView):
+    pass
\ No newline at end of file
diff --git a/lms/settings.py b/lms/settings.py
index ff764b8..b4ae38d 100644
--- a/lms/settings.py
+++ b/lms/settings.py
@@ -68,6 +68,8 @@ DATABASES = {
     'default': env.db(),
 }
 
+COURSE_PROGRESS_SECRET_KEY = "!gf?s3@4Hr5#J#&%Kfr@56s"
+
 SESSION_ENGINE = 'redis_sessions.session'
 CELERY_EMAIL_CHUNK_SIZE = 1
 
diff --git a/lms/urls.py b/lms/urls.py
index 9ed625b..9acba7b 100644
--- a/lms/urls.py
+++ b/lms/urls.py
@@ -1,7 +1,7 @@
 from django.conf.urls import url, include
 from django.contrib import admin
 from django.views.static import serve
-from finance.views import YandexCheckView, YandexAvisoView
+from finance.views import YandexCheckView, YandexAvisoView, DemoYandexCheckView, DemoYandexAvisoView
 
 from django.conf import settings
 
@@ -12,5 +12,7 @@ urlpatterns = [
     url(r'^static/(?P<path>.*)/$', serve, {'document_root': settings.STATIC_ROOT}),
     url(r'^wallet/pay/check/$', YandexCheckView.as_view(), name='yandex_money_check'),
     url(r'^wallet/pay/result/$', YandexAvisoView.as_view(), name='yandex_money_notice'),
-    url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
+    url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework')),
+    url(r'^yandex-money/check/$', DemoYandexCheckView.as_view()),
+    url(r'^yandex-money/aviso/$', DemoYandexAvisoView.as_view())
 ]
diff --git a/progress/serializers.py b/progress/serializers.py
index ea27df1..c2570e9 100644
--- a/progress/serializers.py
+++ b/progress/serializers.py
@@ -1,6 +1,8 @@
 from rest_framework import serializers
 
 from progress.models import Progress, ProgressLesson
+import jwt
+from django.conf import settings
 
 
 class ProgressSerializer(serializers.ModelSerializer):
@@ -15,6 +17,23 @@ class ProgressSerializer(serializers.ModelSerializer):
         return [ProgressLessonSerializer(i).data for i in self.progresslesson_set.all()]
 
 
+class SecureProgressSerializer(serializers.ModelSerializer):
+    jwt_token = serializers.SerializerMethodField()
+
+    class Meta:
+        model = Progress
+        fields = ('jwt_token', )
+
+    @staticmethod
+    def get_jwt_token(self):
+        payload = {
+            'lessons': [ProgressLessonSerializer(i).data for i in self.progresslesson_set.all()],
+            'course_token': str(self.course_token),
+            'only_watch': self.only_watch,
+        }
+        return jwt.encode(payload, settings.COURSE_PROGRESS_SECRET_KEY, algorithm='HS256')
+
+
 class ProgressAnalyticSerializer(serializers.ModelSerializer):
     name = serializers.SerializerMethodField()
     email = serializers.SerializerMethodField()
@@ -47,8 +66,8 @@ class ProgressLessonSerializer(serializers.ModelSerializer):
 
     @staticmethod
     def get_student(self):
-        return {'name': self.progress.user.get_full_name(), "out_key": self.progress.user.out_key}
+        return {'name': self.progress.user.get_full_name(), "out_key": str(self.progress.user.out_key)}
 
     @staticmethod
     def get_course_token(self):
-        return self.progress.course_token
\ No newline at end of file
+        return str(self.progress.course_token)
diff --git a/progress/views.py b/progress/views.py
index 2b43719..842a3ec 100644
--- a/progress/views.py
+++ b/progress/views.py
@@ -14,7 +14,8 @@ from django.db.models import Q
 
 from courses.models import Course
 from progress.models import ProgressLesson, Progress
-from progress.serializers import ProgressAnalyticSerializer, ProgressLessonSerializer, ProgressSerializer
+from progress.serializers import ProgressAnalyticSerializer, ProgressLessonSerializer, ProgressSerializer, \
+    SecureProgressSerializer
 from courses.api import CourseProgressApi, CourseParamsApi
 from progress.tasks import add_next_lesson
 
@@ -175,47 +176,45 @@ class StudentUpdateProgress(APIView):
     @staticmethod
     def post(request):
         lesson_token = request.JSON.get('lesson_token', None)
-        course_token = request.JSON.get('course_token', None)
         comment = request.JSON.get('comment', None)
 
-        if lesson_token is None or course_token is None:
-            return Response('Не передан слаг курса или токен урока', status=400)
-        try:
-            student = request.user
+        if lesson_token is None:
+            return Response('Не передан токен урока', status=400)
 
-            p = Progress.objects.get(user=student, course_token=course_token)
+        student = request.user
 
-            try:
-                pv = ProgressLesson.objects.get(
-                    progress=p,
-                    lesson_token=lesson_token,
-                )
+        try:
+            pv = ProgressLesson.objects.get(
+                progress__user=student,
+                lesson_token=lesson_token,
+            )
 
-                if not pv.status == ProgressLesson.STATUSES.wait:
-                    if pv.checker == p.teacher and not comment is None:
-                        pv.status = ProgressLesson.STATUSES.wait
-                        pv.comment_tokens.append(comment)
+            if pv.status == ProgressLesson.STATUSES.done:
+                Response(SecureProgressSerializer(pv.progress).data, status=200)
 
-                    elif pv.checker == p.user:
-                        pv.status = ProgressLesson.STATUSES.done
-                        pv.finish_date = datetime.datetime.now()
+            if not pv.status == ProgressLesson.STATUSES.wait:
+                if pv.checker == pv.progress.user:
+                    pv.status = ProgressLesson.STATUSES.done
+                    pv.finish_date = datetime.datetime.now()
 
-                    else:
-                        raise ValueError("Этого никогда не должно происходить, но я уверен, что произойдёт")
+                elif not comment is None and\
+                        not pv.progress.progresslesson_set.filter(status=ProgressLesson.STATUSES.wait).exists():
+                    pv.status = ProgressLesson.STATUSES.wait
+                    pv.comment_tokens.append(comment)
 
-                    pv.save()
+                elif comment is None:
+                    return Response("Не преложен комментарий", status=400)
 
                 else:
-                    return Response("Ошибка прав доступа", status=403)
+                    return Response("В настоящее время, мы уже  проверяем одно из ваших домашних заданий. <br> Как "
+                                    "только оно будет успешно сдано - вы сможете продолжить.", status=403)
 
-            except ProgressLesson.DoesNotExist:
-                return Response('Урок не проходится этим пользователем', status=403)
+            elif not comment is None:
+                pv.comment_tokens.append(comment)
 
-            if pv.status == ProgressLesson.STATUSES.done:
-                # TODO: Ассинхроннаязадача для celery
-                add_next_lesson(p)
+            pv.save()
 
-            return Response(ProgressSerializer(p).data, status=200)
+            return Response(SecureProgressSerializer(pv.progress).data, status=200)
 
         except Progress.DoesNotExist:
             return Response('Не найден прогресс по заданным параметрам', status=404)
@@ -292,6 +291,7 @@ class SetProgress(APIView):
             course_slug = request.JSON.get('course_slug', None)
             topic_sort = int(request.JSON.get('topic', 1))
             lesson_sort = int(request.JSON.get('lesson', 1))
+            only_watch = request.JSON.get('only_watch', False)
             force = request.JSON.get('force', False)
 
             if course_slug is None:
@@ -319,6 +319,9 @@ class SetProgress(APIView):
                 teacher = get_user_model().objects.get(out_key=course.get_teacher())
                 progress = Progress.objects.create(course_token=course.token, user=student, teacher=teacher)
 
+            progress.only_watch = only_watch
+            progress.save()
+
             token_list = []
             lesson_list = []
             for topic_idx, topic in enumerate(course.topic_set.all()):
diff --git a/storage/views.py b/storage/views.py
index 55770d6..1b7c14c 100644
--- a/storage/views.py
+++ b/storage/views.py
@@ -1,3 +1,6 @@
+import base64
+import json
+
 from rest_framework.renderers import JSONRenderer
 from rest_framework.response import Response
 from rest_framework.views import APIView
@@ -44,12 +47,19 @@ class CommentView(APIView):
 
     @staticmethod
     def get(request):
-        token = request.GET.get('token', None)
+        base64_tokens = request.GET.get('base64_tokens', None)
 
-        if not token:
+        if not base64_tokens:
             return Response("Attribute token not set", status=400)
 
-        try:
-            return Response(CommentSerializer(Comment.objects.get(token=token)).data, status=200)
-        except Comment.DoesNotExist:
-            return Response("Comment not found", status=404)
+        tokens = json.loads(base64.b64decode(base64_tokens).decode('utf-8'))
+        comments = []
+
+        for token in tokens:
+            try:
+                comment = Comment.objects.get(token=token)
+                comments.append(comment)
+            except Comment.DoesNotExist:
+                pass
+
+        return Response([CommentSerializer(comment).data for comment in comments], status=200)