diff --git a/src/messenger-connections.js b/src/messenger-connections.js
new file mode 100644
index 0000000..bfb1520
--- /dev/null
+++ b/src/messenger-connections.js
@@ -0,0 +1,97 @@
+function normalizeOptionalText(value) {
+  const normalized = String(value || '').trim();
+  return normalized || null;
+}
+
+export function normalizeTelegramProfile(profile) {
+  if (!profile || typeof profile !== 'object') {
+    return {
+      displayName: null,
+      username: null,
+      avatarFileId: null,
+      avatarFileUniqueId: null,
+    };
+  }
+
+  return {
+    displayName: normalizeOptionalText(profile.displayName),
+    username: normalizeOptionalText(profile.username)?.replace(/^@+/, '') || null,
+    avatarFileId: normalizeOptionalText(profile.avatarFileId),
+    avatarFileUniqueId: normalizeOptionalText(profile.avatarFileUniqueId),
+  };
+}
+
+export function profileFromTelegramMiniAppUser(user) {
+  if (!user || typeof user !== 'object') {
+    return normalizeTelegramProfile(null);
+  }
+
+  const firstName = String(user.first_name || '').trim();
+  const lastName = String(user.last_name || '').trim();
+  const displayName = `${firstName} ${lastName}`.trim();
+
+  return normalizeTelegramProfile({
+    displayName,
+    username: user.username,
+  });
+}
+
+export async function upsertActiveMessengerConnection(prisma, { userId, type, channelId, profile = null }) {
+  const normalizedChannelId = String(channelId || '').trim();
+  if (!userId || !type || !normalizedChannelId) {
+    throw new Error('userId, type and channelId are required to connect messenger.');
+  }
+
+  const normalizedProfile = type === 'TELEGRAM'
+    ? normalizeTelegramProfile(profile)
+    : normalizeTelegramProfile(null);
+
+  return prisma.$transaction(async (tx) => {
+    await tx.messengerConnection.updateMany({
+      where: {
+        userId,
+        type,
+        isActive: true,
+        NOT: { channelId: normalizedChannelId },
+      },
+      data: { isActive: false },
+    });
+
+    await tx.messengerConnection.updateMany({
+      where: {
+        type,
+        channelId: normalizedChannelId,
+        isActive: true,
+        NOT: { userId },
+      },
+      data: { isActive: false },
+    });
+
+    return tx.messengerConnection.upsert({
+      where: {
+        userId_type_channelId: {
+          userId,
+          type,
+          channelId: normalizedChannelId,
+        },
+      },
+      update: {
+        isActive: true,
+        displayName: normalizedProfile.displayName,
+        username: normalizedProfile.username,
+        avatarFileId: normalizedProfile.avatarFileId,
+        avatarFileUniqueId: normalizedProfile.avatarFileUniqueId,
+      },
+      create: {
+        userId,
+        type,
+        channelId: normalizedChannelId,
+        isActive: true,
+        displayName: normalizedProfile.displayName,
+        username: normalizedProfile.username,
+        avatarFileId: normalizedProfile.avatarFileId,
+        avatarFileUniqueId: normalizedProfile.avatarFileUniqueId,
+      },
+    });
+  });
+}
diff --git a/src/messenger.js b/src/messenger.js
index 167792b..e3c0c12 100644
--- a/src/messenger.js
+++ b/src/messenger.js
@@ -6,6 +6,35 @@ function maskChannel(channelId) {
   return `${text.slice(0, 3)}***${text.slice(-3)}`;
 }
 
+function buildTelegramButton(buttonUrl, buttonText) {
+  const url = String(buttonUrl || '').trim();
+  if (!url) {
+    return null;
+  }
+
+  const text = String(buttonText || '').trim() || 'Открыть кабинет';
+  const miniAppBaseUrl = String(
+    process.env.TELEGRAM_MINI_APP_URL ||
+    process.env.WEB_FRONTEND_URL ||
+    process.env.NUXT_PUBLIC_SITE_URL ||
+    '',
+  ).trim().replace(/\/$/, '');
+
+  if (miniAppBaseUrl && url.startsWith(miniAppBaseUrl)) {
+    return {
+      text,
+      web_app: {
+        url,
+      },
+    };
+  }
+
+  return {
+    text,
+    url,
+  };
+}
+
 async function sendTelegramMessage(channelId, message, options = {}) {
   const token = process.env.TELEGRAM_BOT_TOKEN;
   if (!token) {
@@ -16,6 +45,7 @@ async function sendTelegramMessage(channelId, message, options = {}) {
   }
 
   try {
+    const button = buildTelegramButton(options.buttonUrl, options.buttonText);
     const response = await fetch(`https://api.telegram.org/bot${token}/sendMessage`, {
       method: 'POST',
       headers: { 'content-type': 'application/json' },
@@ -23,14 +53,11 @@ async function sendTelegramMessage(channelId, message, options = {}) {
         chat_id: channelId,
         text: message,
         disable_web_page_preview: true,
-        ...(options.buttonUrl
+        ...(button
           ? {
               reply_markup: {
                 inline_keyboard: [[
-                  {
-                    text: options.buttonText || 'Открыть кабинет',
-                    url: options.buttonUrl,
-                  },
+                  button,
                 ]],
               },
             }
@@ -121,7 +148,7 @@ export async function sendMessengerMessage({ type, channelId, message, buttonUrl
   };
 }
 
-export async function dispatchToUserConnections(prisma, userId, message) {
+export async function dispatchToUserConnections(prisma, userId, message, options = {}) {
   const connections = await prisma.messengerConnection.findMany({
     where: {
       userId,
@@ -139,6 +166,8 @@ export async function dispatchToUserConnections(prisma, userId, message) {
       type: connection.type,
       channelId: connection.channelId,
       message,
+      buttonUrl: options.buttonUrl,
+      buttonText: options.buttonText,
     });
 
     results.push({
diff --git a/src/resolvers.js b/src/resolvers.js
index f4653a7..222e2a5 100644
--- a/src/resolvers.js
+++ b/src/resolvers.js
@@ -15,6 +15,7 @@ import {
   isManagerRole,
 } from './access.js';
 import { sendLoginCodeEmail } from './mailer.js';
+import { upsertActiveMessengerConnection } from './messenger-connections.js';
 import { dispatchToUserConnections, sendMessengerMessage } from './messenger.js';
 import { dateTimeScalar, jsonScalar } from './scalars.js';
 import { fetchTelegramConnectionProfile } from './telegram.js';
@@ -281,6 +282,33 @@ function formatOrderStatusMessage(order, status, note) {
   return `Заказ ${order.code} изменил статус: ${status}.${suffix}`;
 }
 
+function buildFrontendAppUrl(path) {
+  const baseUrl = String(
+    process.env.TELEGRAM_MINI_APP_URL ||
+    process.env.WEB_FRONTEND_URL ||
+    process.env.NUXT_PUBLIC_SITE_URL ||
+    '',
+  ).trim().replace(/\/$/, '');
+
+  const normalizedPath = String(path || '').trim();
+  if (!baseUrl || !normalizedPath.startsWith('/')) {
+    return null;
+  }
+
+  return `${baseUrl}${normalizedPath}`;
+}
+
+function buildUserOrderPath(orderId, role) {
+  const normalizedOrderId = String(orderId || '').trim();
+  if (!normalizedOrderId) {
+    return '';
+  }
+
+  return isManagerRole(role)
+    ? `/client-orders/${normalizedOrderId}`
+    : `/orders/${normalizedOrderId}`;
+}
+
 async function notifyOrderStakeholders(context, order, status, note) {
   const recipients = [order.customerId, order.managerId].filter(Boolean);
   if (!recipients.length) {
@@ -289,8 +317,22 @@ async function notifyOrderStakeholders(context, order, status, note) {
 
   const message = formatOrderStatusMessage(order, status, note);
   const uniqueRecipients = [...new Set(recipients)];
+  const users = await context.prisma.user.findMany({
+    where: {
+      id: { in: uniqueRecipients },
+    },
+    select: {
+      id: true,
+      role: true,
+    },
+  });
+  const userRoleMap = new Map(users.map((user) => [user.id, user.role]));
+
   await Promise.allSettled(
-    uniqueRecipients.map((userId) => dispatchToUserConnections(context.prisma, userId, message)),
+    uniqueRecipients.map((userId) => dispatchToUserConnections(context.prisma, userId, message, {
+      buttonUrl: buildFrontendAppUrl(buildUserOrderPath(order.id, userRoleMap.get(userId))),
+      buttonText: 'Открыть заказ',
+    })),
   );
 }
 
@@ -820,41 +862,11 @@ export const resolvers = {
       }
 
       if (login.messengerConnection) {
-        await context.prisma.messengerConnection.updateMany({
-          where: {
-            userId: user.id,
-            type: login.messengerConnection.type,
-            isActive: true,
-            NOT: { channelId: login.messengerConnection.channelId },
-          },
-          data: { isActive: false },
-        });
-
-        await context.prisma.messengerConnection.upsert({
-          where: {
-            userId_type_channelId: {
-              userId: user.id,
-              type: login.messengerConnection.type,
-              channelId: login.messengerConnection.channelId,
-            },
-          },
-          update: {
-            isActive: true,
-            displayName: login.messengerConnection.displayName ?? null,
-            username: login.messengerConnection.username ?? null,
-            avatarFileId: login.messengerConnection.avatarFileId ?? null,
-            avatarFileUniqueId: login.messengerConnection.avatarFileUniqueId ?? null,
-          },
-          create: {
-            userId: user.id,
-            type: login.messengerConnection.type,
-            channelId: login.messengerConnection.channelId,
-            isActive: true,
-            displayName: login.messengerConnection.displayName ?? null,
-            username: login.messengerConnection.username ?? null,
-            avatarFileId: login.messengerConnection.avatarFileId ?? null,
-            avatarFileUniqueId: login.messengerConnection.avatarFileUniqueId ?? null,
-          },
+        await upsertActiveMessengerConnection(context.prisma, {
+          userId: user.id,
+          type: login.messengerConnection.type,
+          channelId: login.messengerConnection.channelId,
+          profile: login.messengerConnection,
         });
       }
 
diff --git a/src/server.js b/src/server.js
index 2a5ecc0..78b87db 100644
--- a/src/server.js
+++ b/src/server.js
@@ -15,15 +15,18 @@ import {
   consumeMessengerStartSession,
   extractAuthTokenFromRequest,
   hasMessengerStartSession,
+  issueAccessToken,
   issueTemporaryLoginToken,
   verifyAccessToken,
 } from './auth.js';
 import { canManagerAccessUser, isManagerRole } from './access.js';
 import { buildContext } from './context.js';
+import { profileFromTelegramMiniAppUser, normalizeTelegramProfile, upsertActiveMessengerConnection } from './messenger-connections.js';
 import { sendMessengerMessage } from './messenger.js';
 import { prisma } from './prisma-client.js';
 import { resolvers } from './resolvers.js';
 import { telegramApi, telegramFileUrl } from './telegram.js';
+import { validateTelegramMiniAppInitData } from './telegram-mini-app.js';
 
 const typeDefs = readFileSync(new URL('./schema.graphql', import.meta.url), 'utf8');
 
@@ -92,16 +95,28 @@ function normalizeRedirectPath(value) {
   return redirectPath;
 }
 
-function normalizeTelegramProfile(profile) {
-  if (!profile || typeof profile !== 'object') {
-    return null;
-  }
+function presentTelegramMiniAppUser(user) {
+  const firstName = String(user?.first_name || '').trim();
+  const lastName = String(user?.last_name || '').trim();
 
   return {
-    displayName: String(profile.displayName || '').trim() || null,
-    username: String(profile.username || '').trim().replace(/^@+/, '') || null,
-    avatarFileId: String(profile.avatarFileId || '').trim() || null,
-    avatarFileUniqueId: String(profile.avatarFileUniqueId || '').trim() || null,
+    id: String(user?.id || '').trim(),
+    firstName,
+    lastName: lastName || null,
+    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',
+  };
+}
+
+function presentAuthUser(user) {
+  return {
+    id: user.id,
+    email: user.email,
+    fullName: user.fullName,
+    role: user.role,
+    companyId: user.companyId ?? null,
   };
 }
 
@@ -150,6 +165,93 @@ app.post('/auth/messenger-start', async (req, res) => {
   });
 });
 
+app.post('/auth/telegram-mini-app/session', async (req, res) => {
+  let telegram;
+  try {
+    telegram = validateTelegramMiniAppInitData(req.body?.initData);
+  } catch (error) {
+    res.status(401).json({ error: error.message });
+    return;
+  }
+
+  const channelId = String(telegram.user.id);
+  const connection = await prisma.messengerConnection.findFirst({
+    where: {
+      type: 'TELEGRAM',
+      channelId,
+      isActive: true,
+    },
+    include: {
+      user: true,
+    },
+    orderBy: { createdAt: 'desc' },
+  });
+
+  if (!connection?.user) {
+    res.json({
+      ok: true,
+      authenticated: false,
+      telegramUser: presentTelegramMiniAppUser(telegram.user),
+    });
+    return;
+  }
+
+  await upsertActiveMessengerConnection(prisma, {
+    userId: connection.user.id,
+    type: 'TELEGRAM',
+    channelId,
+    profile: profileFromTelegramMiniAppUser(telegram.user),
+  });
+
+  const session = issueAccessToken(connection.user.id);
+  res.json({
+    ok: true,
+    authenticated: true,
+    accessToken: session.accessToken,
+    expiresAt: session.expiresAt.toISOString(),
+    user: presentAuthUser(connection.user),
+    telegramUser: presentTelegramMiniAppUser(telegram.user),
+  });
+});
+
+app.post('/auth/telegram-mini-app/connect', async (req, res) => {
+  const user = await resolveAuthenticatedUserFromRequest(req);
+  if (!user) {
+    res.status(401).json({ error: 'Authentication required.' });
+    return;
+  }
+
+  let telegram;
+  try {
+    telegram = validateTelegramMiniAppInitData(req.body?.initData);
+  } catch (error) {
+    res.status(401).json({ error: error.message });
+    return;
+  }
+
+  const connection = await upsertActiveMessengerConnection(prisma, {
+    userId: user.id,
+    type: 'TELEGRAM',
+    channelId: telegram.user.id,
+    profile: profileFromTelegramMiniAppUser(telegram.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,
+    },
+    telegramUser: presentTelegramMiniAppUser(telegram.user),
+  });
+});
+
 app.post('/bot/messenger-login', async (req, res) => {
   const webhookToken = process.env.BOT_LOGIN_WEBHOOK_TOKEN;
   const providedToken = req.body?.token;
diff --git a/src/telegram-mini-app.js b/src/telegram-mini-app.js
new file mode 100644
index 0000000..9713c82
--- /dev/null
+++ b/src/telegram-mini-app.js
@@ -0,0 +1,90 @@
+import crypto from 'node:crypto';
+
+const TELEGRAM_MINI_APP_AUTH_MAX_AGE_SECONDS = Number(process.env.TELEGRAM_MINI_APP_AUTH_MAX_AGE_SECONDS ?? 60 * 60);
+
+function requireTelegramBotToken() {
+  const token = String(process.env.TELEGRAM_BOT_TOKEN || '').trim();
+  if (!token) {
+    throw new Error('TELEGRAM_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 parseTelegramUser(rawUser) {
+  if (!rawUser) {
+    return null;
+  }
+
+  const parsed = JSON.parse(rawUser);
+  if (!parsed || typeof parsed !== 'object' || !parsed.id) {
+    return null;
+  }
+
+  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,
+  };
+}
+
+export function validateTelegramMiniAppInitData(initDataRaw) {
+  const initData = String(initDataRaw || '').trim();
+  if (!initData) {
+    throw new Error('Telegram initData is required.');
+  }
+
+  const params = new URLSearchParams(initData);
+  const receivedHash = String(params.get('hash') || '').trim().toLowerCase();
+  if (!receivedHash) {
+    throw new Error('Telegram initData hash is missing.');
+  }
+
+  const authDate = Number(params.get('auth_date'));
+  if (!Number.isFinite(authDate) || authDate <= 0) {
+    throw new Error('Telegram initData auth_date is invalid.');
+  }
+
+  const now = Math.floor(Date.now() / 1000);
+  if (now - authDate > TELEGRAM_MINI_APP_AUTH_MAX_AGE_SECONDS) {
+    throw new Error('Telegram initData is expired.');
+  }
+
+  const checkEntries = [...params.entries()]
+    .filter(([key]) => key !== 'hash' && key !== 'signature')
+    .sort(([leftKey], [rightKey]) => leftKey.localeCompare(rightKey))
+    .map(([key, value]) => `${key}=${value}`);
+  const dataCheckString = checkEntries.join('\n');
+
+  const secretKey = crypto.createHmac('sha256', 'WebAppData').update(requireTelegramBotToken()).digest();
+  const expectedHash = crypto.createHmac('sha256', secretKey).update(dataCheckString).digest('hex');
+
+  if (!timingSafeEqualHex(expectedHash, receivedHash)) {
+    throw new Error('Telegram initData signature is invalid.');
+  }
+
+  const user = parseTelegramUser(params.get('user'));
+  if (!user?.id) {
+    throw new Error('Telegram user is missing in initData.');
+  }
+
+  return {
+    authDate: new Date(authDate * 1000),
+    queryId: String(params.get('query_id') || '').trim() || null,
+    startParam: String(params.get('start_param') || '').trim() || null,
+    user,
+  };
+}