diff --git a/bro.config.js b/bro.config.js
index 0025a67..2690651 100644
--- a/bro.config.js
+++ b/bro.config.js
@@ -22,7 +22,7 @@ module.exports = {
   },
   features: {
     'challenge-admin': {
-      // add your features here in the format [featureName]: { value: string }
+      'use-chain-submissions-api': { value: 'true' },
     },
   },
   config: {
diff --git a/src/__data__/api/api.ts b/src/__data__/api/api.ts
index f41ea8e..b03e42b 100644
--- a/src/__data__/api/api.ts
+++ b/src/__data__/api/api.ts
@@ -15,6 +15,8 @@ import type {
   UpdateChainRequest,
   SubmitRequest,
   TestSubmissionResult,
+  ChainSubmissionsResponse,
+  SubmissionStatus,
 } from '../../types/challenge'
 
 export const api = createApi({
@@ -143,6 +145,17 @@ export const api = createApi({
       transformResponse: (response: { body: ChallengeSubmission[] }) => response.body,
       providesTags: ['Submission'],
     }),
+    getChainSubmissions: builder.query<
+      ChainSubmissionsResponse,
+      { chainId: string; userId?: string; status?: SubmissionStatus }
+    >({
+      query: ({ chainId, userId, status }) => ({
+        url: `/challenge/chain/${chainId}/submissions`,
+        params: userId || status ? { userId, status } : undefined,
+      }),
+      transformResponse: (response: { body: ChainSubmissionsResponse }) => response.body,
+      providesTags: ['Submission'],
+    }),
 
     // Test submission (LLM check without creating a real submission)
     testSubmission: builder.mutation<TestSubmissionResult, SubmitRequest>({
@@ -178,6 +191,7 @@ export const {
   useGetSystemStatsV2Query,
   useGetUserStatsQuery,
   useGetUserSubmissionsQuery,
+  useGetChainSubmissionsQuery,
   useTestSubmissionMutation,
 } = api
 
diff --git a/src/pages/submissions/SubmissionsPage.tsx b/src/pages/submissions/SubmissionsPage.tsx
index 82b5b96..c45d561 100644
--- a/src/pages/submissions/SubmissionsPage.tsx
+++ b/src/pages/submissions/SubmissionsPage.tsx
@@ -17,7 +17,13 @@ import {
   Select,
   createListCollection,
 } from '@chakra-ui/react'
-import { useGetChainsQuery, useGetSystemStatsV2Query, useGetUserSubmissionsQuery } from '../../__data__/api/api'
+import { getFeatureValue } from '@brojs/cli'
+import {
+  useGetChainsQuery,
+  useGetChainSubmissionsQuery,
+  useGetSystemStatsV2Query,
+  useGetUserSubmissionsQuery,
+} from '../../__data__/api/api'
 import { LoadingSpinner } from '../../components/LoadingSpinner'
 import { ErrorAlert } from '../../components/ErrorAlert'
 import { EmptyState } from '../../components/EmptyState'
@@ -28,7 +34,6 @@ import type {
   SubmissionStatus,
   ChallengeTask,
   ChallengeUser,
-  ActiveParticipant,
 } from '../../types/challenge'
 
 export const SubmissionsPage: React.FC = () => {
@@ -36,30 +41,48 @@ export const SubmissionsPage: React.FC = () => {
   const navigate = useNavigate()
   const { chainId } = useParams<{ chainId?: string }>()
 
+  // Проверяем feature flag
+  const featureValue = getFeatureValue('challenge-admin', 'use-chain-submissions-api')
+  const useNewApi = featureValue?.value === 'true'
+
   // Состояние для выбранного пользователя и фильтров
   const [selectedUserId, setSelectedUserId] = useState<string | null>(null)
   const [searchQuery, setSearchQuery] = useState('')
   const [statusFilter, setStatusFilter] = useState<SubmissionStatus | 'all'>('all')
 
   // Получаем список цепочек
-  const { 
-    data: chains, 
-    isLoading: isChainsLoading, 
+  const {
+    data: chains,
+    isLoading: isChainsLoading,
     error: chainsError,
     refetch: refetchChains,
   } = useGetChainsQuery()
 
-  // Получаем общую статистику (без фильтра по chainId - получаем всех участников)
+  // Новый API: получаем данные по цепочке через новый эндпоинт
+  const {
+    data: chainData,
+    isLoading: isChainDataLoading,
+    error: chainDataError,
+    refetch: refetchChainData,
+  } = useGetChainSubmissionsQuery(
+    {
+      chainId: chainId!,
+      userId: selectedUserId || undefined,
+      status: statusFilter !== 'all' ? statusFilter : undefined,
+    },
+    { skip: !chainId || !useNewApi }
+  )
+
+  // Старый API: получаем общую статистику и submissions отдельно
   const {
     data: stats,
     isLoading: isStatsLoading,
     error: statsError,
     refetch: refetchStats,
   } = useGetSystemStatsV2Query(undefined, {
-    skip: !chainId, // Загружаем только когда выбрана цепочка
+    skip: !chainId || useNewApi,
   })
 
-  // Получаем submissions для выбранного пользователя
   const {
     data: submissions,
     isLoading: isSubmissionsLoading,
@@ -67,43 +90,50 @@ export const SubmissionsPage: React.FC = () => {
     refetch: refetchSubmissions,
   } = useGetUserSubmissionsQuery(
     { userId: selectedUserId!, taskId: undefined },
-    { skip: !selectedUserId }
+    { skip: !selectedUserId || useNewApi }
   )
 
-  const isLoading = isChainsLoading || (chainId && isStatsLoading) || (selectedUserId && isSubmissionsLoading)
-  const error = chainsError || statsError || submissionsError
+  const isLoading =
+    isChainsLoading ||
+    (chainId && useNewApi && isChainDataLoading) ||
+    (chainId && !useNewApi && isStatsLoading) ||
+    (selectedUserId && !useNewApi && isSubmissionsLoading)
+
+  const error = chainsError || (useNewApi ? chainDataError : statsError || submissionsError)
 
   const handleRetry = () => {
     refetchChains()
-    refetchStats()
-    if (selectedUserId) {
-      refetchSubmissions()
+    if (chainId) {
+      if (useNewApi) {
+        refetchChainData()
+      } else {
+        refetchStats()
+        if (selectedUserId) {
+          refetchSubmissions()
+        }
+      }
     }
   }
 
-  // Получаем данные выбранной цепочки из списка chains
+  // Получаем данные выбранной цепочки из списка chains (для старого API)
   const selectedChain = useMemo(() => {
     if (!chainId || !chains) return null
     return chains.find((c) => c.id === chainId) || null
   }, [chainId, chains])
 
-  // Получаем taskIds из текущей цепочки
+  // Получаем taskIds из текущей цепочки (для старого API)
   const chainTaskIds = useMemo(() => {
     if (!selectedChain) return new Set<string>()
     return new Set(selectedChain.tasks.map((t) => t.id))
   }, [selectedChain])
 
-  // Фильтруем участников - только те, кто имеет прогресс в этой цепочке
-  const chainParticipants = useMemo(() => {
-    if (!stats?.activeParticipants || !chainId) return []
-    
+  // Старый API: фильтруем участников - только те, кто имеет прогресс в этой цепочке
+  const chainParticipantsOld = useMemo(() => {
+    if (!stats?.activeParticipants || !chainId || useNewApi) return []
+
     return stats.activeParticipants
       .map((participant) => {
-        // Ищем прогресс участника по выбранной цепочке
         const chainProgress = participant.chainProgress?.find((cp) => cp.chainId === chainId)
-        
-        // Если нет прогресса по этой цепочке, пробуем рассчитать на основе submissions
-        // Для простоты показываем всех участников с базовым прогрессом 0%
         return {
           ...participant,
           progressPercent: chainProgress?.progressPercent ?? 0,
@@ -112,43 +142,90 @@ export const SubmissionsPage: React.FC = () => {
         }
       })
       .sort((a, b) => a.progressPercent - b.progressPercent)
-  }, [stats?.activeParticipants, chainId, selectedChain])
+  }, [stats?.activeParticipants, chainId, selectedChain, useNewApi])
 
-  // Фильтруем submissions только по заданиям из текущей цепочки
-  const filteredSubmissions = useMemo(() => {
-    if (!submissions || chainTaskIds.size === 0) return []
+  // Старый API: фильтруем submissions только по заданиям из текущей цепочки
+  const filteredSubmissionsOld = useMemo(() => {
+    if (!submissions || chainTaskIds.size === 0 || useNewApi) return []
 
     const normalizedSearchQuery = (searchQuery ?? '').toLowerCase()
 
     return submissions.filter((submission) => {
-      // Фильтр по цепочке (по taskId)
       const rawTask = submission.task as ChallengeTask | string | undefined
-      const taskId = rawTask && typeof rawTask === 'object' && 'id' in rawTask 
-        ? rawTask.id 
-        : typeof rawTask === 'string' ? rawTask : ''
-      
+      const taskId =
+        rawTask && typeof rawTask === 'object' && 'id' in rawTask
+          ? rawTask.id
+          : typeof rawTask === 'string'
+            ? rawTask
+            : ''
+
       if (!chainTaskIds.has(taskId)) return false
 
-      // Фильтр по поиску
       const rawUser = submission.user as ChallengeUser | string | undefined
       const nickname =
         rawUser && typeof rawUser === 'object' && 'nickname' in rawUser
           ? (rawUser.nickname ?? '')
           : ''
+
       const title =
         rawTask && typeof rawTask === 'object' && 'title' in rawTask
           ? (rawTask.title ?? '')
           : ''
+
       const matchesSearch =
         nickname.toLowerCase().includes(normalizedSearchQuery) ||
         title.toLowerCase().includes(normalizedSearchQuery)
 
-      // Фильтр по статусу
       const matchesStatus = statusFilter === 'all' || submission.status === statusFilter
 
       return matchesSearch && matchesStatus
     })
-  }, [submissions, chainTaskIds, searchQuery, statusFilter])
+  }, [submissions, chainTaskIds, searchQuery, statusFilter, useNewApi])
+
+  // Новый API: фильтруем submissions по поисковому запросу (статус уже отфильтрован на сервере)
+  const filteredSubmissionsNew = useMemo(() => {
+    if (!chainData?.submissions || !useNewApi) return []
+
+    const normalizedSearchQuery = (searchQuery ?? '').toLowerCase()
+    if (!normalizedSearchQuery) return chainData.submissions
+
+    return chainData.submissions.filter((submission) => {
+      const rawUser = submission.user as ChallengeUser | string | undefined
+      const rawTask = submission.task as ChallengeTask | string | undefined
+
+      const nickname =
+        rawUser && typeof rawUser === 'object' && 'nickname' in rawUser
+          ? (rawUser.nickname ?? '')
+          : typeof rawUser === 'string'
+            ? rawUser
+            : ''
+
+      const title =
+        rawTask && typeof rawTask === 'object' && 'title' in rawTask
+          ? (rawTask.title ?? '')
+          : typeof rawTask === 'string'
+            ? rawTask
+            : ''
+
+      return (
+        nickname.toLowerCase().includes(normalizedSearchQuery) ||
+        title.toLowerCase().includes(normalizedSearchQuery)
+      )
+    })
+  }, [chainData?.submissions, searchQuery, useNewApi])
+
+  // Выбираем данные в зависимости от фичи
+  const filteredSubmissions = useNewApi ? filteredSubmissionsNew : filteredSubmissionsOld
+
+  // Сортируем участников по прогрессу
+  const sortedParticipants = useMemo(() => {
+    if (useNewApi) {
+      if (!chainData?.participants) return []
+      return [...chainData.participants].sort((a, b) => a.progressPercent - b.progressPercent)
+    } else {
+      return chainParticipantsOld
+    }
+  }, [chainData?.participants, chainParticipantsOld, useNewApi])
 
   const formatDate = (dateStr: string) => {
     return new Date(dateStr).toLocaleString('ru-RU', {
@@ -250,7 +327,7 @@ export const SubmissionsPage: React.FC = () => {
   }
 
   // Если цепочка выбрана но данных нет
-  if (!selectedChain) {
+  if (useNewApi && !chainData) {
     return (
       <Box>
         <Link to={URLs.submissions} style={{ textDecoration: 'none', color: '#319795' }}>
@@ -263,7 +340,21 @@ export const SubmissionsPage: React.FC = () => {
     )
   }
 
-  const participants: ActiveParticipant[] = stats?.activeParticipants || []
+  if (!useNewApi && !selectedChain) {
+    return (
+      <Box>
+        <Link to={URLs.submissions} style={{ textDecoration: 'none', color: '#319795' }}>
+          <Text fontSize="sm" _hover={{ textDecoration: 'underline' }} mb={4}>
+            ← {t('challenge.admin.submissions.back.to.chains')}
+          </Text>
+        </Link>
+        <ErrorAlert message={t('challenge.admin.common.not.found')} onRetry={handleRetry} />
+      </Box>
+    )
+  }
+
+  const chainName = useNewApi ? chainData?.chain.name : selectedChain?.name
+  const chainTasksCount = useNewApi ? chainData?.chain.tasks.length : selectedChain?.tasks.length
 
   return (
     <Box>
@@ -276,14 +367,14 @@ export const SubmissionsPage: React.FC = () => {
             </Text>
           </Link>
         </HStack>
-        <Heading mb={2}>{selectedChain.name}</Heading>
+        <Heading mb={2}>{chainName}</Heading>
         <Text color="gray.600" fontSize="sm">
-          {t('challenge.admin.submissions.chain.description', { count: selectedChain.tasks.length })}
+          {t('challenge.admin.submissions.chain.description', { count: chainTasksCount ?? 0 })}
         </Text>
       </Box>
 
       {/* Выбор участника и фильтры */}
-      {participants.length > 0 && (
+      {sortedParticipants.length > 0 && (
         <VStack mb={4} gap={3} align="stretch">
           <HStack gap={4} align="center" wrap="wrap">
             {selectedUserId && (
@@ -342,7 +433,7 @@ export const SubmissionsPage: React.FC = () => {
             {t('challenge.admin.submissions.participants.description')}
           </Text>
 
-          {chainParticipants.length === 0 ? (
+          {sortedParticipants.length === 0 ? (
             <EmptyState
               title={t('challenge.admin.submissions.participants.empty.title')}
               description={t('challenge.admin.submissions.participants.empty.description')}
@@ -357,7 +448,7 @@ export const SubmissionsPage: React.FC = () => {
               }}
               gap={3}
             >
-              {chainParticipants.map((participant) => {
+              {sortedParticipants.map((participant) => {
                 const colorPalette =
                   participant.progressPercent >= 70
                     ? 'green'
diff --git a/src/types/challenge.ts b/src/types/challenge.ts
index 12d8f9b..427f503 100644
--- a/src/types/challenge.ts
+++ b/src/types/challenge.ts
@@ -244,3 +244,28 @@ export interface TestSubmissionResult {
   feedback?: string
 }
 
+// ========== Chain Submissions API ==========
+
+export interface ChainSubmissionsParticipant {
+  userId: string
+  nickname: string
+  completedTasks: number
+  totalTasks: number
+  progressPercent: number
+}
+
+export interface ChainSubmissionsResponse {
+  chain: {
+    id: string
+    name: string
+    tasks: Array<{ id: string; title: string }>
+  }
+  participants: ChainSubmissionsParticipant[]
+  submissions: ChallengeSubmission[]
+  pagination: {
+    total: number
+    limit: number
+    offset: number
+  }
+}
+
diff --git a/stubs/api/index.js b/stubs/api/index.js
index a1cd87c..feaf148 100644
--- a/stubs/api/index.js
+++ b/stubs/api/index.js
@@ -461,4 +461,116 @@ router.get('/challenge/user/:userId/submissions', (req, res) => {
   respond(res, filtered);
 });
 
+// GET /api/challenge/chain/:chainId/submissions
+router.get('/challenge/chain/:chainId/submissions', (req, res) => {
+  const chains = getChains();
+  const submissions = getSubmissions();
+  const users = getUsers();
+  
+  const chainId = req.params.chainId;
+  const userId = req.query.userId;
+  const status = req.query.status;
+  const limit = parseInt(req.query.limit) || 100;
+  const offset = parseInt(req.query.offset) || 0;
+  
+  // Найти цепочку
+  const chain = chains.find(c => c.id === chainId);
+  if (!chain) {
+    return respondError(res, 'Chain not found', 404);
+  }
+  
+  // Получить taskIds из цепочки
+  const taskIds = new Set(chain.tasks.map(t => t.id));
+  
+  // Фильтровать submissions по taskIds цепочки
+  let filteredSubmissions = submissions.filter(s => {
+    const taskId = typeof s.task === 'object' ? s.task.id : s.task;
+    return taskIds.has(taskId);
+  });
+  
+  // Применить фильтр по userId если указан
+  if (userId) {
+    filteredSubmissions = filteredSubmissions.filter(s => {
+      const subUserId = typeof s.user === 'object' ? s.user.id : s.user;
+      return subUserId === userId;
+    });
+  }
+  
+  // Применить фильтр по status если указан
+  if (status) {
+    filteredSubmissions = filteredSubmissions.filter(s => s.status === status);
+  }
+  
+  // Получить уникальных участников
+  const participantMap = new Map();
+  
+  filteredSubmissions.forEach(sub => {
+    const subUserId = typeof sub.user === 'object' ? sub.user.id : sub.user;
+    const subUserNickname = typeof sub.user === 'object' ? sub.user.nickname : '';
+    
+    // Найти nickname если не заполнен
+    let nickname = subUserNickname;
+    if (!nickname) {
+      const user = users.find(u => u.id === subUserId);
+      nickname = user ? user.nickname : subUserId;
+    }
+    
+    if (!participantMap.has(subUserId)) {
+      participantMap.set(subUserId, {
+        userId: subUserId,
+        nickname: nickname,
+        completedTasks: new Set(),
+        totalTasks: chain.tasks.length,
+      });
+    }
+    
+    // Если статус accepted, добавляем taskId в completedTasks
+    if (sub.status === 'accepted') {
+      const taskId = typeof sub.task === 'object' ? sub.task.id : sub.task;
+      participantMap.get(subUserId).completedTasks.add(taskId);
+    }
+  });
+  
+  // Преобразовать в массив и рассчитать прогресс
+  const participants = Array.from(participantMap.values()).map(p => ({
+    userId: p.userId,
+    nickname: p.nickname,
+    completedTasks: p.completedTasks.size,
+    totalTasks: p.totalTasks,
+    progressPercent: p.totalTasks > 0 
+      ? Math.round((p.completedTasks.size / p.totalTasks) * 100) 
+      : 0,
+  }));
+  
+  // Сортировать submissions по дате (новые сначала)
+  filteredSubmissions.sort((a, b) => 
+    new Date(b.submittedAt) - new Date(a.submittedAt)
+  );
+  
+  // Применить пагинацию
+  const total = filteredSubmissions.length;
+  const paginatedSubmissions = filteredSubmissions.slice(offset, offset + limit);
+  
+  // Формируем ответ
+  const response = {
+    chain: {
+      id: chain.id,
+      name: chain.name,
+      tasks: chain.tasks.map(t => ({
+        id: t.id,
+        title: t.title,
+      })),
+    },
+    participants: participants,
+    submissions: paginatedSubmissions,
+    pagination: {
+      total: total,
+      limit: limit,
+      offset: offset,
+    },
+  };
+  
+  respond(res, response);
+});
+
 module.exports = router;