diff --git a/src/max-mini-app.js b/src/max-mini-app.js
new file mode 100644
index 0000000..02a4c69
--- /dev/null
+++ b/src/max-mini-app.js
@@ -0,0 +1,115 @@
+import crypto from 'node:crypto';
+
+const MAX_MINI_APP_AUTH_MAX_AGE_SECONDS = Number(process.env.MAX_MINI_APP_AUTH_MAX_AGE_SECONDS ?? 60 * 60);
+
+function requireMaxBotToken() {
+  const token = String(process.env.MAX_BOT_TOKEN || '').trim();
+  if (!token) {
+    throw new Error('MAX_BOT_TOKEN is not configured.');
+  }
+  return token;
+}
+
+function timingSafeEqualHex(left, right) {
+  const leftBuffer = Buffer.from(String(left || ''), 'hex');
+  const rightBuffer = Buffer.from(String(right || ''), 'hex');
+
+  if (!leftBuffer.length || leftBuffer.length !== rightBuffer.length) {
+    return false;
+  }
+
+  return crypto.timingSafeEqual(leftBuffer, rightBuffer);
+}
+
+function parseJsonParam(rawValue, fieldName) {
+  if (!rawValue) {
+    return null;
+  }
+
+  let parsed;
+  try {
+    parsed = JSON.parse(rawValue);
+  } catch {
+    throw new Error(`MAX ${fieldName} is invalid.`);
+  }
+
+  if (!parsed || typeof parsed !== 'object') {
+    throw new Error(`MAX ${fieldName} is invalid.`);
+  }
+
+  return parsed;
+}
+
+function parseMaxUser(rawUser) {
+  const parsed = parseJsonParam(rawUser, 'user');
+  if (!parsed?.id) {
+    throw new Error('MAX user is missing in initData.');
+  }
+
+  return {
+    id: String(parsed.id),
+    first_name: String(parsed.first_name || '').trim(),
+    last_name: String(parsed.last_name || '').trim() || null,
+    username: String(parsed.username || '').trim() || null,
+    language_code: String(parsed.language_code || '').trim() || null,
+    photo_url: String(parsed.photo_url || '').trim() || null,
+  };
+}
+
+function parseMaxChat(rawChat) {
+  const parsed = parseJsonParam(rawChat, 'chat');
+  if (!parsed?.id) {
+    return null;
+  }
+
+  return {
+    id: String(parsed.id),
+    type: String(parsed.type || '').trim() || null,
+  };
+}
+
+export function validateMaxMiniAppInitData(initDataRaw) {
+  const initData = String(initDataRaw || '').trim();
+  if (!initData) {
+    throw new Error('MAX initData is required.');
+  }
+
+  const params = new URLSearchParams(initData);
+  const receivedHashes = params.getAll('hash').map((value) => String(value || '').trim().toLowerCase()).filter(Boolean);
+  if (receivedHashes.length !== 1) {
+    throw new Error('MAX initData hash is missing.');
+  }
+
+  const authDate = Number(params.get('auth_date'));
+  if (!Number.isFinite(authDate) || authDate <= 0) {
+    throw new Error('MAX initData auth_date is invalid.');
+  }
+
+  const authDateSeconds = authDate > 1e12 ? Math.floor(authDate / 1000) : Math.floor(authDate);
+
+  const now = Math.floor(Date.now() / 1000);
+  if (now - authDateSeconds > MAX_MINI_APP_AUTH_MAX_AGE_SECONDS) {
+    throw new Error('MAX initData is expired.');
+  }
+
+  const dataCheckString = [...params.entries()]
+    .filter(([key]) => key !== 'hash')
+    .sort(([leftKey], [rightKey]) => leftKey.localeCompare(rightKey))
+    .map(([key, value]) => `${key}=${value}`)
+    .join('\n');
+
+  const secretKey = crypto.createHmac('sha256', 'WebAppData').update(requireMaxBotToken()).digest();
+  const expectedHash = crypto.createHmac('sha256', secretKey).update(dataCheckString).digest('hex');
+
+  if (!timingSafeEqualHex(expectedHash, receivedHashes[0])) {
+    throw new Error('MAX initData signature is invalid.');
+  }
+
+  return {
+    authDate: new Date(authDateSeconds * 1000),
+    queryId: String(params.get('query_id') || '').trim() || null,
+    startParam: String(params.get('start_param') || '').trim() || null,
+    user: parseMaxUser(params.get('user')),
+    chat: parseMaxChat(params.get('chat')),
+  };
+}
diff --git a/src/messenger-connections.js b/src/messenger-connections.js
index bfb1520..b24203b 100644
--- a/src/messenger-connections.js
+++ b/src/messenger-connections.js
@@ -3,7 +3,7 @@ function normalizeOptionalText(value) {
   return normalized || null;
 }
 
-export function normalizeTelegramProfile(profile) {
+function normalizeMessengerProfile(profile) {
   if (!profile || typeof profile !== 'object') {
     return {
       displayName: null,
@@ -21,6 +21,17 @@ export function normalizeTelegramProfile(profile) {
   };
 }
 
+export function normalizeTelegramProfile(profile) {
+  return normalizeMessengerProfile(profile);
+}
+
+export function normalizeMaxProfile(profile) {
+  return normalizeMessengerProfile({
+    displayName: profile?.displayName,
+    username: profile?.username,
+  });
+}
+
 export function profileFromTelegramMiniAppUser(user) {
   if (!user || typeof user !== 'object') {
     return normalizeTelegramProfile(null);
@@ -36,6 +47,21 @@ export function profileFromTelegramMiniAppUser(user) {
   });
 }
 
+export function profileFromMaxMiniAppUser(user) {
+  if (!user || typeof user !== 'object') {
+    return normalizeMaxProfile(null);
+  }
+
+  const firstName = String(user.first_name || '').trim();
+  const lastName = String(user.last_name || '').trim();
+  const displayName = `${firstName} ${lastName}`.trim();
+
+  return normalizeMaxProfile({
+    displayName,
+    username: user.username,
+  });
+}
+
 export async function upsertActiveMessengerConnection(prisma, { userId, type, channelId, profile = null }) {
   const normalizedChannelId = String(channelId || '').trim();
   if (!userId || !type || !normalizedChannelId) {
@@ -44,7 +70,9 @@ export async function upsertActiveMessengerConnection(prisma, { userId, type, ch
 
   const normalizedProfile = type === 'TELEGRAM'
     ? normalizeTelegramProfile(profile)
-    : normalizeTelegramProfile(null);
+    : type === 'MAX'
+      ? normalizeMaxProfile(profile)
+      : normalizeMessengerProfile(null);
 
   return prisma.$transaction(async (tx) => {
     await tx.messengerConnection.updateMany({
diff --git a/src/server.js b/src/server.js
index 78b87db..45a347e 100644
--- a/src/server.js
+++ b/src/server.js
@@ -21,7 +21,14 @@ import {
 } from './auth.js';
 import { canManagerAccessUser, isManagerRole } from './access.js';
 import { buildContext } from './context.js';
-import { profileFromTelegramMiniAppUser, normalizeTelegramProfile, upsertActiveMessengerConnection } from './messenger-connections.js';
+import {
+  normalizeMaxProfile,
+  normalizeTelegramProfile,
+  profileFromMaxMiniAppUser,
+  profileFromTelegramMiniAppUser,
+  upsertActiveMessengerConnection,
+} from './messenger-connections.js';
+import { validateMaxMiniAppInitData } from './max-mini-app.js';
 import { sendMessengerMessage } from './messenger.js';
 import { prisma } from './prisma-client.js';
 import { resolvers } from './resolvers.js';
@@ -96,6 +103,14 @@ function normalizeRedirectPath(value) {
 }
 
 function presentTelegramMiniAppUser(user) {
+  return presentMiniAppUser(user, 'Пользователь Telegram');
+}
+
+function presentMaxMiniAppUser(user) {
+  return presentMiniAppUser(user, 'Пользователь MAX');
+}
+
+function presentMiniAppUser(user, fallbackDisplayName) {
   const firstName = String(user?.first_name || '').trim();
   const lastName = String(user?.last_name || '').trim();
 
@@ -106,7 +121,7 @@ function presentTelegramMiniAppUser(user) {
     username: String(user?.username || '').trim() || null,
     languageCode: String(user?.language_code || '').trim() || null,
     photoUrl: String(user?.photo_url || '').trim() || null,
-    displayName: `${firstName} ${lastName}`.trim() || firstName || 'Пользователь Telegram',
+    displayName: `${firstName} ${lastName}`.trim() || firstName || fallbackDisplayName,
   };
 }
 
@@ -252,6 +267,93 @@ app.post('/auth/telegram-mini-app/connect', async (req, res) => {
   });
 });
 
+app.post('/auth/max-mini-app/session', async (req, res) => {
+  let max;
+  try {
+    max = validateMaxMiniAppInitData(req.body?.initData);
+  } catch (error) {
+    res.status(401).json({ error: error.message });
+    return;
+  }
+
+  const channelId = String(max.user.id);
+  const connection = await prisma.messengerConnection.findFirst({
+    where: {
+      type: 'MAX',
+      channelId,
+      isActive: true,
+    },
+    include: {
+      user: true,
+    },
+    orderBy: { createdAt: 'desc' },
+  });
+
+  if (!connection?.user) {
+    res.json({
+      ok: true,
+      authenticated: false,
+      maxUser: presentMaxMiniAppUser(max.user),
+    });
+    return;
+  }
+
+  await upsertActiveMessengerConnection(prisma, {
+    userId: connection.user.id,
+    type: 'MAX',
+    channelId,
+    profile: profileFromMaxMiniAppUser(max.user),
+  });
+
+  const session = issueAccessToken(connection.user.id);
+  res.json({
+    ok: true,
+    authenticated: true,
+    accessToken: session.accessToken,
+    expiresAt: session.expiresAt.toISOString(),
+    user: presentAuthUser(connection.user),
+    maxUser: presentMaxMiniAppUser(max.user),
+  });
+});
+
+app.post('/auth/max-mini-app/connect', async (req, res) => {
+  const user = await resolveAuthenticatedUserFromRequest(req);
+  if (!user) {
+    res.status(401).json({ error: 'Authentication required.' });
+    return;
+  }
+
+  let max;
+  try {
+    max = validateMaxMiniAppInitData(req.body?.initData);
+  } catch (error) {
+    res.status(401).json({ error: error.message });
+    return;
+  }
+
+  const connection = await upsertActiveMessengerConnection(prisma, {
+    userId: user.id,
+    type: 'MAX',
+    channelId: max.user.id,
+    profile: profileFromMaxMiniAppUser(max.user),
+  });
+
+  res.json({
+    ok: true,
+    connection: {
+      id: connection.id,
+      userId: connection.userId,
+      type: connection.type,
+      channelId: connection.channelId,
+      displayName: connection.displayName,
+      username: connection.username,
+      avatarAvailable: Boolean(connection.avatarFileId),
+      isActive: connection.isActive,
+    },
+    maxUser: presentMaxMiniAppUser(max.user),
+  });
+});
+
 app.post('/bot/messenger-login', async (req, res) => {
   const webhookToken = process.env.BOT_LOGIN_WEBHOOK_TOKEN;
   const providedToken = req.body?.token;
@@ -301,7 +403,9 @@ app.post('/bot/messenger-login', async (req, res) => {
     messengerConnection: {
       type: channel,
       channelId,
-      ...normalizeTelegramProfile(req.body?.profile),
+      ...(channel === 'TELEGRAM'
+        ? normalizeTelegramProfile(req.body?.profile)
+        : normalizeMaxProfile(req.body?.profile)),
     },
   });
   const frontendUrl = (
@@ -310,7 +414,7 @@ app.post('/bot/messenger-login', async (req, res) => {
     'http://localhost:3000'
   ).replace(/\/$/, '');
   const nextPath = startSession.redirectPath || (
-    channel === 'TELEGRAM'
+    channel === 'TELEGRAM' || channel === 'MAX'
       ? `/profile/notifications/success?connected=${channel.toLowerCase()}`
       : ''
   );