diff --git a/apps/api-gateway/package.json b/apps/api-gateway/package.json
index 1c5de41..2d89055 100644
--- a/apps/api-gateway/package.json
+++ b/apps/api-gateway/package.json
@@ -20,11 +20,13 @@
     "@nestjs/swagger": "^11.2.3",
     "class-transformer": "^0.5.1",
     "class-validator": "^0.14.3",
+    "cookie-parser": "^1.4.7",
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.2"
   },
   "devDependencies": {
     "@nestjs/cli": "^11.0.14",
+    "@types/cookie-parser": "^1.4.10",
     "@types/node": "^24.10.1",
     "typescript": "^5.9.3"
   }
diff --git a/apps/api-gateway/src/app.module.ts b/apps/api-gateway/src/app.module.ts
index 56cbba1..108b7b2 100644
--- a/apps/api-gateway/src/app.module.ts
+++ b/apps/api-gateway/src/app.module.ts
@@ -14,6 +14,7 @@ import { ProfileController } from './controllers/profile.controller';
 import { DocumentsController } from './controllers/documents.controller';
 import { AddressesController } from './controllers/addresses.controller';
 import { OAuthController } from './controllers/oauth.controller';
+import { FedcmController } from './controllers/fedcm.controller';
 import { WellKnownController, OAuthAuthorizeDiscoveryController } from './controllers/well-known.controller';
 import { AdvancedAuthController } from './controllers/advanced-auth.controller';
 import { FamilyController } from './controllers/family.controller';
@@ -25,6 +26,7 @@ import { AdminBotController } from './controllers/admin-bot.controller';
 import { TelegramBotApiController } from './controllers/telegram-bot-api.controller';
 import { CoreGrpcService } from './core-grpc.service';
 import { AdminGuard, RbacManageGuard, SuperAdminGuard } from './guards/admin.guard';
+import { FedcmCookieInterceptor } from './interceptors/fedcm-cookie.interceptor';
 
 @Module({
   imports: [
@@ -59,7 +61,7 @@ import { AdminGuard, RbacManageGuard, SuperAdminGuard } from './guards/admin.gua
       }
     ])
   ],
-  controllers: [AuthController, AdminController, RbacController, SecurityController, SettingsController, PublicSettingsController, HealthController, ProfileController, DocumentsController, AddressesController, OAuthController, WellKnownController, OAuthAuthorizeDiscoveryController, AdvancedAuthController, FamilyController, ChatController, NotificationsController, MediaController, BotController, AdminBotController, TelegramBotApiController],
-  providers: [CoreGrpcService, AdminGuard, RbacManageGuard, SuperAdminGuard]
+  controllers: [AuthController, AdminController, RbacController, SecurityController, SettingsController, PublicSettingsController, HealthController, ProfileController, DocumentsController, AddressesController, OAuthController, FedcmController, WellKnownController, OAuthAuthorizeDiscoveryController, AdvancedAuthController, FamilyController, ChatController, NotificationsController, MediaController, BotController, AdminBotController, TelegramBotApiController],
+  providers: [CoreGrpcService, AdminGuard, RbacManageGuard, SuperAdminGuard, FedcmCookieInterceptor]
 })
 export class AppModule {}
diff --git a/apps/api-gateway/src/controllers/auth.controller.ts b/apps/api-gateway/src/controllers/auth.controller.ts
index 006d83b..03855d2 100644
--- a/apps/api-gateway/src/controllers/auth.controller.ts
+++ b/apps/api-gateway/src/controllers/auth.controller.ts
@@ -1,13 +1,15 @@
-import { Body, Controller, Get, Headers, Ip, Post } from '@nestjs/common';
+import { Body, Controller, Get, Headers, Ip, Post, UseInterceptors } from '@nestjs/common';
 import { JwtService } from '@nestjs/jwt';
 import { ApiBearerAuth, ApiBody, ApiOperation, ApiTags } from '@nestjs/swagger';
 import { firstValueFrom } from 'rxjs';
 import { CoreGrpcService } from '../core-grpc.service';
 import { BeginTotpLoginDto, IdentifyDto, LdapLoginDto, LoginDto, PasswordlessOtpDto, PasswordlessVerifyDto, PasswordLoginDto, RefreshSessionDto, RegisterDto, VerifyPinDto, VerifyTotpLoginDto } from '../dto/auth.dto';
 import { resolveAuthorizedPayload, verifyAccessToken } from '../session-auth';
+import { FedcmCookieInterceptor } from '../interceptors/fedcm-cookie.interceptor';
 
 @ApiTags('Аутентификация')
 @Controller('auth')
+@UseInterceptors(FedcmCookieInterceptor)
 export class AuthController {
   constructor(
     private readonly core: CoreGrpcService,
diff --git a/apps/api-gateway/src/controllers/fedcm.controller.ts b/apps/api-gateway/src/controllers/fedcm.controller.ts
new file mode 100644
index 0000000..875db7b
--- /dev/null
+++ b/apps/api-gateway/src/controllers/fedcm.controller.ts
@@ -0,0 +1,192 @@
+import {
+  Controller,
+  Get,
+  Headers,
+  HttpCode,
+  Options,
+  Post,
+  Query,
+  Req,
+  Res,
+  UnauthorizedException
+} from '@nestjs/common';
+import { JwtService } from '@nestjs/jwt';
+import { ApiOperation, ApiTags } from '@nestjs/swagger';
+import { firstValueFrom } from 'rxjs';
+import type { Request, Response } from 'express';
+import { CoreGrpcService } from '../core-grpc.service';
+import { applyFedcmCorsHeaders, applyFedcmPreflightHeaders } from '../lib/fedcm-cors';
+import { resolveFedcmSessionFromRequest, setFedcmSessionCookie } from '../lib/fedcm-cookie';
+import { resolveFrontendUrl, resolveOAuthIssuer } from '../lib/oauth-issuer';
+import { assertSessionUnlocked, verifyAccessToken } from '../session-auth';
+
+type FedcmAccountsResponse = {
+  accounts: Array<{
+    id: string;
+    name: string;
+    given_name?: string;
+    email?: string;
+    picture?: string;
+    approved_clients?: string[];
+  }>;
+};
+
+@ApiTags('FedCM')
+@Controller('fedcm')
+export class FedcmController {
+  constructor(
+    private readonly core: CoreGrpcService,
+    private readonly jwt: JwtService
+  ) {}
+
+  @Options('accounts')
+  @HttpCode(204)
+  accountsPreflight(@Headers('origin') origin: string | undefined, @Res({ passthrough: true }) res: Response) {
+    applyFedcmPreflightHeaders(res, origin);
+  }
+
+  @Options('id_assertion')
+  @HttpCode(204)
+  idAssertionPreflight(@Headers('origin') origin: string | undefined, @Res({ passthrough: true }) res: Response) {
+    applyFedcmPreflightHeaders(res, origin);
+  }
+
+  @Options('client_metadata')
+  @HttpCode(204)
+  clientMetadataPreflight(@Headers('origin') origin: string | undefined, @Res({ passthrough: true }) res: Response) {
+    applyFedcmPreflightHeaders(res, origin);
+  }
+
+  @Get('config.json')
+  @ApiOperation({ summary: 'FedCM provider config', description: 'Конфигурация Identity Provider для Federated Credential Management API.' })
+  async config(@Res({ passthrough: true }) res: Response) {
+    res.setHeader('Content-Type', 'application/json');
+    res.setHeader('Cache-Control', 'public, max-age=300');
+
+    const issuer = await resolveOAuthIssuer(this.core);
+    const frontendUrl = await resolveFrontendUrl(this.core);
+    let projectName = 'MVK ID';
+
+    try {
+      const setting = (await firstValueFrom(this.core.settings.GetSetting({ key: 'PROJECT_NAME' }))) as { value?: string };
+      if (setting.value?.trim()) {
+        projectName = setting.value.trim();
+      }
+    } catch {
+      // fallback
+    }
+
+    return {
+      accounts_endpoint: `${issuer}/fedcm/accounts`,
+      client_metadata_endpoint: `${issuer}/fedcm/client_metadata`,
+      id_assertion_endpoint: `${issuer}/fedcm/id_assertion`,
+      login_url: `${frontendUrl}/auth/login`,
+      signup_url: `${frontendUrl}/auth/register`,
+      branding: {
+        background_color: '#ffffff',
+        color: '#3390ec',
+        icons: [{ url: `${frontendUrl}/favicon.ico`, size: 32 }]
+      },
+      accounts: {
+        include_anonymous: false
+      },
+      fields: ['name', 'email', 'picture'],
+      display: projectName
+    };
+  }
+
+  @Get('accounts')
+  @ApiOperation({ summary: 'FedCM accounts', description: 'Возвращает аккаунты пользователя по FedCM-сессии (cookie).' })
+  async accounts(
+    @Req() req: Request,
+    @Headers('origin') origin: string | undefined,
+    @Res({ passthrough: true }) res: Response
+  ): Promise<FedcmAccountsResponse> {
+    applyFedcmCorsHeaders(res, origin);
+    res.setHeader('Content-Type', 'application/json');
+
+    const session = await resolveFedcmSessionFromRequest(this.jwt, req.headers.cookie);
+    if (!session) {
+      return { accounts: [] };
+    }
+
+    const result = (await firstValueFrom(
+      this.core.fedcm.GetAccounts({ userId: session.sub, sessionId: session.sessionId })
+    )) as FedcmAccountsResponse;
+
+    return result ?? { accounts: [] };
+  }
+
+  @Get('client_metadata')
+  @ApiOperation({ summary: 'FedCM client metadata', description: 'Метаданные клиента для UI FedCM.' })
+  async clientMetadata(
+    @Query('client_id') clientId: string | undefined,
+    @Headers('origin') origin: string | undefined,
+    @Res({ passthrough: true }) res: Response
+  ) {
+    applyFedcmCorsHeaders(res, origin);
+    res.setHeader('Content-Type', 'application/json');
+
+    if (!clientId?.trim()) {
+      throw new UnauthorizedException('Передайте client_id');
+    }
+
+    return firstValueFrom(this.core.fedcm.GetClientMetadata({ clientId: clientId.trim() }));
+  }
+
+  @Post('id_assertion')
+  @HttpCode(200)
+  @ApiOperation({ summary: 'FedCM id assertion', description: 'Выдаёт OIDC id_token для выбранного аккаунта и OAuth-клиента.' })
+  async idAssertion(
+    @Req() req: Request,
+    @Headers('origin') origin: string | undefined,
+    @Res({ passthrough: true }) res: Response
+  ) {
+    applyFedcmCorsHeaders(res, origin);
+    res.setHeader('Content-Type', 'application/json');
+
+    const session = await resolveFedcmSessionFromRequest(this.jwt, req.headers.cookie);
+    if (!session) {
+      throw new UnauthorizedException('Сессия FedCM не найдена');
+    }
+
+    const body = (req.body ?? {}) as Record<string, unknown>;
+    const clientId = String(body.client_id ?? body.clientId ?? '').trim();
+    const accountId = String(body.account_id ?? body.accountId ?? '').trim();
+    if (!clientId || !accountId) {
+      throw new UnauthorizedException('Передайте client_id и account_id');
+    }
+
+    return firstValueFrom(
+      this.core.fedcm.IssueIdAssertion({
+        userId: session.sub,
+        sessionId: session.sessionId,
+        clientId,
+        accountId
+      })
+    );
+  }
+
+  @Post('session/sync')
+  @HttpCode(200)
+  @ApiOperation({
+    summary: 'Синхронизировать FedCM cookie',
+    description: 'Устанавливает HttpOnly cookie для FedCM по Bearer access token (для уже авторизованных пользователей IdP).'
+  })
+  async syncSession(
+    @Headers('authorization') authorization: string | undefined,
+    @Res({ passthrough: true }) res: Response
+  ) {
+    const payload = await verifyAccessToken(this.jwt, authorization);
+    if (!payload.sessionId) {
+      throw new UnauthorizedException('Сессия не найдена');
+    }
+    await assertSessionUnlocked(this.core, payload);
+    await setFedcmSessionCookie(res, this.jwt, {
+      sub: payload.sub,
+      sessionId: payload.sessionId,
+      pinVerified: true
+    });
+    return { synced: true };
+  }
+}
diff --git a/apps/api-gateway/src/controllers/well-known.controller.ts b/apps/api-gateway/src/controllers/well-known.controller.ts
index a2f2fdc..dcabe39 100644
--- a/apps/api-gateway/src/controllers/well-known.controller.ts
+++ b/apps/api-gateway/src/controllers/well-known.controller.ts
@@ -1,5 +1,7 @@
-import { Controller, Get } from '@nestjs/common';
+import { Controller, Get, Res } from '@nestjs/common';
 import { ApiOperation, ApiTags } from '@nestjs/swagger';
+import type { Response } from 'express';
+import { firstValueFrom } from 'rxjs';
 import { CoreGrpcService } from '../core-grpc.service';
 import { buildOpenIdConfiguration, resolveOAuthIssuer } from '../lib/oauth-issuer';
 
@@ -8,6 +10,20 @@ import { buildOpenIdConfiguration, resolveOAuthIssuer } from '../lib/oauth-issue
 export class WellKnownController {
   constructor(private readonly core: CoreGrpcService) {}
 
+  @Get('web-identity')
+  @ApiOperation({
+    summary: 'FedCM web identity manifest',
+    description: 'Манифест Federated Credential Management API, указывающий на конфигурацию провайдера.'
+  })
+  async webIdentity(@Res({ passthrough: true }) res: Response) {
+    res.setHeader('Content-Type', 'application/json');
+    res.setHeader('Cache-Control', 'public, max-age=300');
+    const issuer = await resolveOAuthIssuer(this.core);
+    return {
+      provider_urls: [`${issuer}/fedcm/config.json`]
+    };
+  }
+
   @Get('openid-configuration')
   @ApiOperation({
     summary: 'OpenID Connect Discovery',
diff --git a/apps/api-gateway/src/core-grpc.service.ts b/apps/api-gateway/src/core-grpc.service.ts
index 0fb5bd4..5b01eb0 100644
--- a/apps/api-gateway/src/core-grpc.service.ts
+++ b/apps/api-gateway/src/core-grpc.service.ts
@@ -15,6 +15,7 @@ export class CoreGrpcService implements OnModuleInit {
   documents!: Record<string, GrpcMethod>;
   addresses!: Record<string, GrpcMethod>;
   oauth!: Record<string, GrpcMethod>;
+  fedcm!: Record<string, GrpcMethod>;
   otp!: Record<string, GrpcMethod>;
   advancedAuth!: Record<string, GrpcMethod>;
   notifications!: Record<string, GrpcMethod>;
@@ -35,6 +36,7 @@ export class CoreGrpcService implements OnModuleInit {
     this.documents = this.client.getService<Record<string, GrpcMethod>>('DocumentsService');
     this.addresses = this.client.getService<Record<string, GrpcMethod>>('AddressesService');
     this.oauth = this.client.getService<Record<string, GrpcMethod>>('OAuthCoreService');
+    this.fedcm = this.client.getService<Record<string, GrpcMethod>>('FedcmService');
     this.otp = this.client.getService<Record<string, GrpcMethod>>('OtpService');
     this.advancedAuth = this.client.getService<Record<string, GrpcMethod>>('AdvancedAuthService');
     this.family = this.client.getService<Record<string, GrpcMethod>>('FamilyService');
diff --git a/apps/api-gateway/src/interceptors/fedcm-cookie.interceptor.ts b/apps/api-gateway/src/interceptors/fedcm-cookie.interceptor.ts
new file mode 100644
index 0000000..72b3176
--- /dev/null
+++ b/apps/api-gateway/src/interceptors/fedcm-cookie.interceptor.ts
@@ -0,0 +1,21 @@
+import { CallHandler, ExecutionContext, Injectable, NestInterceptor } from '@nestjs/common';
+import { JwtService } from '@nestjs/jwt';
+import { Observable, tap } from 'rxjs';
+import type { Response } from 'express';
+import { attachFedcmCookieFromAuthResult } from '../lib/fedcm-cookie';
+
+@Injectable()
+export class FedcmCookieInterceptor implements NestInterceptor {
+  constructor(private readonly jwt: JwtService) {}
+
+  intercept(context: ExecutionContext, next: CallHandler): Observable<unknown> {
+    const http = context.switchToHttp();
+    const response = http.getResponse<Response>();
+
+    return next.handle().pipe(
+      tap((data) => {
+        attachFedcmCookieFromAuthResult(response, this.jwt, data);
+      })
+    );
+  }
+}
diff --git a/apps/api-gateway/src/lib/fedcm-cookie.ts b/apps/api-gateway/src/lib/fedcm-cookie.ts
new file mode 100644
index 0000000..28b9161
--- /dev/null
+++ b/apps/api-gateway/src/lib/fedcm-cookie.ts
@@ -0,0 +1,128 @@
+import type { Response } from 'express';
+import { JwtService } from '@nestjs/jwt';
+
+export const FEDCM_SESSION_COOKIE = 'lendry_fedcm_sess';
+
+export interface FedcmSessionPayload {
+  sub: string;
+  sessionId: string;
+  pinVerified: boolean;
+}
+
+function cookieSecureEnabled() {
+  if (process.env.FEDCM_COOKIE_SECURE === 'true') return true;
+  if (process.env.FEDCM_COOKIE_SECURE === 'false') return false;
+  return process.env.NODE_ENV === 'production';
+}
+
+function cookieMaxAgeSeconds() {
+  const parsed = Number(process.env.FEDCM_COOKIE_MAX_AGE ?? 2_592_000);
+  return Number.isFinite(parsed) && parsed > 0 ? parsed : 2_592_000;
+}
+
+export async function signFedcmSessionPayload(jwt: JwtService, payload: FedcmSessionPayload) {
+  return jwt.signAsync(
+    { sub: payload.sub, sessionId: payload.sessionId, pinVerified: payload.pinVerified, typ: 'fedcm_session' },
+    {
+      secret: process.env.JWT_ACCESS_SECRET ?? 'docker-access-secret',
+      expiresIn: cookieMaxAgeSeconds(),
+      issuer: 'id.lendry.ru'
+    }
+  );
+}
+
+export async function verifyFedcmSessionToken(jwt: JwtService, token: string): Promise<FedcmSessionPayload | null> {
+  try {
+    const payload = await jwt.verifyAsync<{ sub: string; sessionId: string; pinVerified?: boolean; typ?: string }>(token, {
+      secret: process.env.JWT_ACCESS_SECRET ?? 'docker-access-secret',
+      issuer: 'id.lendry.ru'
+    });
+    if (payload.typ !== 'fedcm_session' || !payload.sub || !payload.sessionId) {
+      return null;
+    }
+    if (payload.pinVerified === false) {
+      return null;
+    }
+    return { sub: payload.sub, sessionId: payload.sessionId, pinVerified: true };
+  } catch {
+    return null;
+  }
+}
+
+export async function setFedcmSessionCookie(res: Response, jwt: JwtService, payload: FedcmSessionPayload) {
+  if (!payload.sub || !payload.sessionId || payload.pinVerified === false) {
+    return;
+  }
+
+  const secure = cookieSecureEnabled();
+  const value = await signFedcmSessionPayload(jwt, payload);
+
+  res.cookie(FEDCM_SESSION_COOKIE, value, {
+    httpOnly: true,
+    secure,
+    sameSite: secure ? 'none' : 'lax',
+    path: '/',
+    maxAge: cookieMaxAgeSeconds() * 1000
+  });
+}
+
+export function clearFedcmSessionCookie(res: Response) {
+  const secure = cookieSecureEnabled();
+  res.clearCookie(FEDCM_SESSION_COOKIE, {
+    httpOnly: true,
+    secure,
+    sameSite: secure ? 'none' : 'lax',
+    path: '/'
+  });
+}
+
+export function readFedcmSessionCookie(cookieHeader?: string): string | null {
+  if (!cookieHeader) return null;
+  const parts = cookieHeader.split(';');
+  for (const part of parts) {
+    const [rawKey, ...rawValue] = part.trim().split('=');
+    if (rawKey === FEDCM_SESSION_COOKIE) {
+      const value = rawValue.join('=').trim();
+      return value || null;
+    }
+  }
+  return null;
+}
+
+export async function resolveFedcmSessionFromRequest(
+  jwt: JwtService,
+  cookieHeader?: string
+): Promise<FedcmSessionPayload | null> {
+  const token = readFedcmSessionCookie(cookieHeader);
+  if (!token) return null;
+  return verifyFedcmSessionToken(jwt, token);
+}
+
+export function attachFedcmCookieFromAuthResult(
+  res: Response,
+  jwt: JwtService,
+  result: unknown
+): void {
+  if (!result || typeof result !== 'object') return;
+  const data = result as {
+    accessToken?: string;
+    sessionId?: string;
+    pinVerified?: boolean;
+    requiresPin?: boolean;
+    user?: { id?: string };
+  };
+
+  if (data.requiresPin || data.pinVerified === false || !data.sessionId) {
+    clearFedcmSessionCookie(res);
+    return;
+  }
+
+  const userId = data.user?.id;
+  if (!userId) return;
+
+  void setFedcmSessionCookie(res, jwt, {
+    sub: userId,
+    sessionId: data.sessionId,
+    pinVerified: true
+  });
+}
diff --git a/apps/api-gateway/src/lib/fedcm-cors.ts b/apps/api-gateway/src/lib/fedcm-cors.ts
new file mode 100644
index 0000000..edb694b
--- /dev/null
+++ b/apps/api-gateway/src/lib/fedcm-cors.ts
@@ -0,0 +1,16 @@
+import type { Response } from 'express';
+
+export function applyFedcmCorsHeaders(res: Response, origin?: string) {
+  if (origin) {
+    res.setHeader('Access-Control-Allow-Origin', origin);
+    res.setHeader('Access-Control-Allow-Credentials', 'true');
+    res.setHeader('Vary', 'Origin');
+  }
+}
+
+export function applyFedcmPreflightHeaders(res: Response, origin?: string) {
+  applyFedcmCorsHeaders(res, origin);
+  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
+  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Sec-Fetch-Dest, Sec-Fetch-Mode, Sec-Fetch-Site');
+  res.setHeader('Access-Control-Max-Age', '86400');
+}
diff --git a/apps/api-gateway/src/main.ts b/apps/api-gateway/src/main.ts
index 0187411..5457f16 100644
--- a/apps/api-gateway/src/main.ts
+++ b/apps/api-gateway/src/main.ts
@@ -1,11 +1,13 @@
 import { ValidationPipe } from '@nestjs/common';
 import { NestFactory } from '@nestjs/core';
 import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
+import cookieParser from 'cookie-parser';
 import { AppModule } from './app.module';
 import { AllExceptionsFilter } from './grpc-exception.filter';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
+  app.use(cookieParser());
   app.enableCors({ origin: true, credentials: true });
   app.useGlobalPipes(
     new ValidationPipe({
diff --git a/apps/docs/components/doc-block-renderer.tsx b/apps/docs/components/doc-block-renderer.tsx
index 3b37139..2fa786c 100644
--- a/apps/docs/components/doc-block-renderer.tsx
+++ b/apps/docs/components/doc-block-renderer.tsx
@@ -1,5 +1,6 @@
 import type { DocBlock } from '@/lib/docs-pages';
 import { OAuthCodeTabs } from '@/components/oauth-code-tabs';
+import { OneTapCodeTabs } from '@/components/one-tap-code-tabs';
 import { AuthLoginCodeTabs } from '@/components/auth-code-tabs';
 import { AuthLdapCodeTabs } from '@/components/auth-ldap-code-tabs';
 import { BotCodeTabs } from '@/components/bot-code-tabs';
@@ -67,6 +68,8 @@ export function DocBlockRenderer({ block }: { block: DocBlock }) {
       );
     case 'oauth-examples':
       return <OAuthCodeTabs />;
+    case 'one-tap-examples':
+      return <OneTapCodeTabs />;
     case 'auth-login-examples':
       return <AuthLoginCodeTabs />;
     case 'auth-ldap-examples':
diff --git a/apps/docs/components/docs-home-content.tsx b/apps/docs/components/docs-home-content.tsx
index 6d5bf00..d77f149 100644
--- a/apps/docs/components/docs-home-content.tsx
+++ b/apps/docs/components/docs-home-content.tsx
@@ -1,7 +1,7 @@
 'use client';
 
 import Link from 'next/link';
-import { ArrowRight, BookOpen, Bot, Code2, Rocket, Shield } from 'lucide-react';
+import { ArrowRight, BookOpen, Bot, Code2, MousePointerClick, Rocket, Shield } from 'lucide-react';
 import { Button } from '@/components/ui/button';
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
 import { docNavigation, groupDocNavigation } from '@/lib/navigation';
@@ -20,6 +20,12 @@ const highlights = [
     description: 'Стандартный OpenID Connect: Discovery, client_id, PKCE, form-urlencoded token. Примеры для PHP без доработки OidcProvider.',
     href: '/docs/oauth'
   },
+  {
+    icon: MousePointerClick,
+    title: 'One Tap Login',
+    description: 'FedCM и виджет sso-widget.js: вход в один клик на сайтах-клиентов без полного редиректа.',
+    href: '/docs/one-tap-login'
+  },
   {
     icon: Bot,
     title: 'Telegram Bot API',
diff --git a/apps/docs/components/one-tap-code-tabs.tsx b/apps/docs/components/one-tap-code-tabs.tsx
new file mode 100644
index 0000000..1145694
--- /dev/null
+++ b/apps/docs/components/one-tap-code-tabs.tsx
@@ -0,0 +1,42 @@
+'use client';
+
+import { useEffect, useMemo, useState } from 'react';
+import { fetchPublicSettingsClient } from '@/lib/api';
+import { buildOneTapExamples, buildOneTapUrls } from '@/lib/one-tap-examples';
+import { resolveFrontendBase, resolveOAuthApiBase } from '@/lib/oauth-url';
+import { CodeExampleTabs } from '@/components/code-example-tabs';
+
+export function OneTapCodeTabs() {
+  const [apiBase, setApiBase] = useState('http://localhost:3000');
+  const [frontendBase, setFrontendBase] = useState('http://localhost:3002');
+  const [projectName, setProjectName] = useState('MVK ID');
+
+  useEffect(() => {
+    void fetchPublicSettingsClient()
+      .then((settings) => {
+        setApiBase(resolveOAuthApiBase(settings));
+        setFrontendBase(resolveFrontendBase(settings));
+        if (settings.PROJECT_NAME?.trim()) {
+          setProjectName(settings.PROJECT_NAME.trim());
+        }
+      })
+      .catch(() => undefined);
+  }, []);
+
+  const urls = useMemo(() => buildOneTapUrls(apiBase, frontendBase, projectName), [apiBase, frontendBase, projectName]);
+  const examples = useMemo(() => buildOneTapExamples(urls), [urls]);
+
+  return (
+    <div className="space-y-3">
+      <p className="text-sm text-zinc-500 dark:text-zinc-400">
+        API (issuer): <code className="rounded bg-zinc-100 px-1.5 py-0.5 dark:bg-zinc-800">{apiBase}</code>
+        {' · '}
+        Frontend / виджет: <code className="rounded bg-zinc-100 px-1.5 py-0.5 dark:bg-zinc-800">{frontendBase}</code>
+        {' — '}
+        из настроек <strong>PUBLIC_API_URL</strong>, <strong>PUBLIC_FRONTEND_URL</strong> и <strong>PROJECT_NAME</strong>.
+      </p>
+      <CodeExampleTabs examples={examples} />
+    </div>
+  );
+
+}
diff --git a/apps/docs/lib/api-endpoints.ts b/apps/docs/lib/api-endpoints.ts
index 9ca41d4..dff2eb4 100644
--- a/apps/docs/lib/api-endpoints.ts
+++ b/apps/docs/lib/api-endpoints.ts
@@ -66,6 +66,48 @@ export const apiReference: ApiTagGroup[] = [
       }
     ]
   },
+  {
+    tag: 'FedCM / One Tap Login',
+    endpoints: [
+      {
+        method: 'GET',
+        path: '/.well-known/web-identity',
+        summary: 'FedCM web identity manifest',
+        description: 'Манифест Federated Credential Management: provider_urls → /fedcm/config.json.'
+      },
+      {
+        method: 'GET',
+        path: '/fedcm/config.json',
+        summary: 'Конфигурация FedCM IdP',
+        description: 'accounts_endpoint, id_assertion_endpoint, login_url, branding.'
+      },
+      {
+        method: 'GET',
+        path: '/fedcm/accounts',
+        summary: 'Список аккаунтов FedCM',
+        description: 'Credentialed GET по cookie lendry_fedcm_sess. CORS с credentials для RP.'
+      },
+      {
+        method: 'POST',
+        path: '/fedcm/id_assertion',
+        summary: 'Выдача id_token FedCM',
+        description: 'Тело: client_id, account_id. Возвращает { token } — OIDC id_token.'
+      },
+      {
+        method: 'GET',
+        path: '/fedcm/client_metadata',
+        summary: 'Метаданные клиента FedCM',
+        description: 'Query: client_id. privacy_policy_url, terms_of_service_url.'
+      },
+      {
+        method: 'POST',
+        path: '/fedcm/session/sync',
+        summary: 'Синхронизация FedCM cookie',
+        description: 'Bearer access token → установка HttpOnly cookie lendry_fedcm_sess.',
+        auth: true
+      }
+    ]
+  },
   {
     tag: 'Профиль и биометрия',
     endpoints: [
diff --git a/apps/docs/lib/docs-pages.ts b/apps/docs/lib/docs-pages.ts
index 7d25079..a739171 100644
--- a/apps/docs/lib/docs-pages.ts
+++ b/apps/docs/lib/docs-pages.ts
@@ -5,6 +5,7 @@ export type DocBlock =
   | { type: 'callout'; variant: 'info' | 'warning' | 'tip'; title: string; text: string }
   | { type: 'table'; headers: string[]; rows: string[][] }
   | { type: 'oauth-examples' }
+  | { type: 'one-tap-examples' }
   | { type: 'auth-login-examples' }
   | { type: 'auth-ldap-examples' }
   | { type: 'bot-examples' }
@@ -956,6 +957,23 @@ $oidc->authenticate(); // client_id, redirect_uri, response_type=code — авт
         title: 'Примеры интеграции',
         blocks: [{ type: 'oauth-examples' }]
       },
+      {
+        id: 'one-tap',
+        title: 'One Tap Login',
+        blocks: [
+          {
+            type: 'paragraph',
+            text: 'Для входа в один клик на сторонних сайтах (FedCM + виджет sso-widget.js) см. отдельный раздел документации.'
+          },
+          {
+            type: 'list',
+            items: [
+              'One Tap Login — FedCM endpoints, подключение sso-widget.js, popup fallback',
+              'Требуется зарегистрированный OAuth client_id и redirect_uri вашего сайта'
+            ]
+          }
+        ]
+      },
       {
         id: 'scopes',
         title: 'Scopes',
@@ -974,6 +992,201 @@ $oidc->authenticate(); // client_id, redirect_uri, response_type=code — авт
       }
     ]
   },
+  {
+    slug: 'one-tap-login',
+    title: 'One Tap Login',
+    description: 'Вход в один клик для сайтов-клиентов: FedCM (основной) и JS SDK с popup (fallback).',
+    sections: [
+      {
+        id: 'overview',
+        title: 'Обзор',
+        blocks: [
+          {
+            type: 'paragraph',
+            text: 'One Tap Login позволяет пользователям вашего сайта войти через Lendry ID без полного редиректа на страницу авторизации. Поддерживаются два режима: Federated Credential Management (FedCM) в современных браузерах и виджет sso-widget.js с popup-окном для остальных.'
+          },
+          {
+            type: 'callout',
+            variant: 'info',
+            title: 'Предварительные требования',
+            text: 'Создайте OAuth-приложение в админ-панели (RBAC → OAuth приложения): укажите redirect_uri вашего сайта, scopes openid profile email и сохраните client_id. Подробнее — раздел «OAuth 2.0 / OIDC».'
+          },
+          {
+            type: 'list',
+            items: [
+              'FedCM — браузер показывает нативный диалог «Войти как …», если пользователь уже залогинен на домене IdP',
+              'Fallback — скрипт sso-widget.js рисует плашку «Войти через …» в правом верхнем углу и открывает popup с OAuth',
+              'Оба режима возвращают OIDC id_token (FedCM) или authorization code / токены (popup) — проверяйте на backend'
+            ]
+          }
+        ]
+      },
+      {
+        id: 'fedcm-endpoints',
+        title: 'FedCM endpoints',
+        blocks: [
+          {
+            type: 'paragraph',
+            text: 'Endpoints размещены на PUBLIC_API_URL (issuer). Локально: http://localhost:3000. При same-origin деплое: https://ваш-домен/idp-api. CORS настроен с credentials: true для запросов с сайтов-клиентов.'
+          },
+          {
+            type: 'table',
+            headers: ['Endpoint', 'Метод', 'Описание'],
+            rows: [
+              ['{PUBLIC_API_URL}/.well-known/web-identity', 'GET', 'Манифест FedCM → provider_urls'],
+              ['{PUBLIC_API_URL}/fedcm/config.json', 'GET', 'Конфигурация IdP (accounts, id_assertion, branding)'],
+              ['{PUBLIC_API_URL}/fedcm/accounts', 'GET', 'Список аккаунтов по cookie lendry_fedcm_sess'],
+              ['{PUBLIC_API_URL}/fedcm/id_assertion', 'POST', 'Выдача id_token для client_id + account_id'],
+              ['{PUBLIC_API_URL}/fedcm/client_metadata', 'GET', '?client_id=… — privacy/terms для UI FedCM'],
+              ['{PUBLIC_API_URL}/fedcm/session/sync', 'POST', 'Установить FedCM cookie по Bearer access token']
+            ]
+          },
+          {
+            type: 'callout',
+            variant: 'warning',
+            title: 'FedCM cookie',
+            text: 'FedCM использует HttpOnly cookie lendry_fedcm_sess на домене IdP (SameSite=None; Secure в production). Cookie устанавливается при входе на IdP или через POST /fedcm/session/sync. localStorage JWT с сайта клиента для FedCM не подходит.'
+          }
+        ]
+      },
+      {
+        id: 'widget',
+        title: 'Подключение виджета (sso-widget.js)',
+        blocks: [
+          {
+            type: 'paragraph',
+            text: 'Скрипт размещён на frontend IdP по адресу {PUBLIC_FRONTEND_URL}/sso-widget.js. Достаточно одного тега script — инициализация выполняется автоматически при загрузке страницы.'
+          },
+          {
+            type: 'table',
+            headers: ['Атрибут data-*', 'Обязательный', 'Описание'],
+            rows: [
+              ['data-client-id', 'Да', 'client_id OAuth-приложения из админки'],
+              ['data-idp-url', 'Нет', 'PUBLIC_API_URL; по умолчанию origin скрипта + /idp-api'],
+              ['data-idp-frontend-url', 'Нет', 'URL frontend IdP для popup; по умолчанию origin скрипта'],
+              ['data-provider-name', 'Нет', 'Название в плашке (по умолчанию MVK ID)'],
+              ['data-redirect-uri', 'Нет', 'redirect_uri OAuth; по умолчанию origin + /auth/callback'],
+              ['data-scope', 'Нет', 'Scopes OAuth (по умолчанию openid profile email)'],
+              ['data-on-success', 'Нет', 'Имя глобальной функции-callback'],
+              ['data-auto-init', 'Нет', 'false — отключить автозапуск; вызовите LendryIdOneTap.init()']
+            ]
+          },
+          {
+            type: 'callout',
+            variant: 'tip',
+            title: 'Логика выбора режима',
+            text: 'Если браузер поддерживает IdentityCredential — скрипт вызывает FedCM. Если нет — показывается плашка в правом верхнем углу; по клику открывается popup OAuth (параметр display=popup).'
+          }
+        ]
+      },
+      {
+        id: 'fedcm-integration',
+        title: 'Интеграция FedCM вручную',
+        blocks: [
+          {
+            type: 'paragraph',
+            text: 'Если вы не используете sso-widget.js, можно вызвать FedCM API напрямую. configURL должен указывать на /fedcm/config.json провайдера.'
+          },
+          {
+            type: 'code',
+            language: 'javascript',
+            title: 'Минимальный пример',
+            code: `const credential = await navigator.credentials.get({
+  identity: {
+    providers: [{
+      configURL: 'https://id.lendry.ru/idp-api/fedcm/config.json',
+      clientId: 'YOUR_CLIENT_ID'
+    }]
+  },
+  mediation: 'optional'
+});
+
+const idToken = credential?.token;
+// Передайте idToken на ваш backend для проверки`
+          },
+          {
+            type: 'list',
+            items: [
+              'mediation: "optional" — показать диалог только при наличии сессии IdP',
+              'mediation: "required" — всегда показывать UI выбора аккаунта',
+              'mediation: "silent" — без UI; вернёт ошибку, если пользователь не залогинен'
+            ]
+          }
+        ]
+      },
+      {
+        id: 'popup-fallback',
+        title: 'Popup fallback и postMessage',
+        blocks: [
+          {
+            type: 'paragraph',
+            text: 'При клике на виджет открывается popup с OAuth authorize. После успешного входа IdP отправляет результат родительскому окну через window.postMessage с типом lendry-sso-onetap.'
+          },
+          {
+            type: 'code',
+            language: 'javascript',
+            title: 'Обработка на сайте клиента',
+            code: `window.addEventListener('message', (event) => {
+  if (event.data?.type !== 'lendry-sso-onetap') return;
+  // Проверяйте event.origin — домен вашего IdP
+  const { token, idToken, accessToken, code, method } = event.data;
+  console.log('Вход через', method);
+});`
+          },
+          {
+            type: 'callout',
+            variant: 'info',
+            title: 'redirect_uri',
+            text: 'redirect_uri должен быть зарегистрирован у OAuth-клиента. Для SPA часто используют https://your-app.com/auth/callback — на этой странице backend обменивает code на токены, либо popup передаёт токен через postMessage.'
+          }
+        ]
+      },
+      {
+        id: 'verify-token',
+        title: 'Проверка токена на backend',
+        blocks: [
+          {
+            type: 'paragraph',
+            text: 'FedCM возвращает id_token (JWT). Проверьте подпись (HS256, секрет JWT_ACCESS_SECRET IdP), issuer = PUBLIC_API_URL и aud = ваш client_id. Альтернатива — обмен authorization code через POST /oauth/token и запрос GET /oauth/userinfo.'
+          },
+          {
+            type: 'list',
+            items: [
+              'Не доверяйте id_token только на frontend — всегда валидируйте на сервере',
+              'client_secret храните только на backend при обмене code → token',
+              'После проверки создайте локальную сессию пользователя (cookie / JWT вашего приложения)'
+            ]
+          }
+        ]
+      },
+      {
+        id: 'examples',
+        title: 'Примеры интеграции',
+        blocks: [{ type: 'one-tap-examples' }]
+      },
+      {
+        id: 'local-dev',
+        title: 'Локальная разработка',
+        blocks: [
+          {
+            type: 'table',
+            headers: ['Сервис', 'URL'],
+            rows: [
+              ['API (FedCM endpoints)', 'http://localhost:3000'],
+              ['Frontend (sso-widget.js)', 'http://localhost:3002/sso-widget.js'],
+              ['Документация', 'http://localhost:3003/docs/one-tap-login']
+            ]
+          },
+          {
+            type: 'callout',
+            variant: 'tip',
+            title: 'Тест FedCM локально',
+            text: 'FedCM cookie в dev использует SameSite=Lax (без Secure). Войдите на http://localhost:3002, затем откройте тестовую страницу клиента с подключённым виджетом. Chrome может требовать флаг chrome://flags/#identity-credentials-api или HTTPS для FedCM — в этом случае проверяйте popup fallback.'
+          }
+        ]
+      }
+    ]
+  },
   {
     slug: 'ldap',
     title: 'LDAP / LDAPS',
diff --git a/apps/docs/lib/navigation.ts b/apps/docs/lib/navigation.ts
index 48e2de2..10e0e8d 100644
--- a/apps/docs/lib/navigation.ts
+++ b/apps/docs/lib/navigation.ts
@@ -10,6 +10,7 @@ export const docNavigation: DocNavItem[] = [
   { slug: 'deployment', title: 'Развёртывание на сервере', group: 'Введение' },
   { slug: 'authentication', title: 'Аутентификация', group: 'Интеграция' },
   { slug: 'oauth', title: 'OAuth 2.0 / OIDC', group: 'Интеграция' },
+  { slug: 'one-tap-login', title: 'One Tap Login', group: 'Интеграция' },
   { slug: 'ldap', title: 'LDAP / LDAPS', group: 'Интеграция' },
   { slug: 'sessions', title: 'Сессии, PIN и удаление аккаунта', group: 'Безопасность' },
   { slug: 'family-chat', title: 'Семья и чат', group: 'Функции' },
diff --git a/apps/docs/lib/oauth-url.ts b/apps/docs/lib/oauth-url.ts
index eebd389..5e6f425 100644
--- a/apps/docs/lib/oauth-url.ts
+++ b/apps/docs/lib/oauth-url.ts
@@ -19,6 +19,23 @@ export function resolveOAuthApiBase(settings: Record<string, string>, fallback =
   return normalizeBaseUrl(fallback);
 }
 
+export function resolveFrontendBase(settings: Record<string, string>, fallback = 'http://localhost:3002') {
+  const publicFrontend = settings.PUBLIC_FRONTEND_URL?.trim();
+  if (publicFrontend) {
+    return normalizeBaseUrl(publicFrontend);
+  }
+
+  const domain = settings.PROJECT_DOMAIN?.trim();
+  if (domain) {
+    if (domain.startsWith('http://') || domain.startsWith('https://')) {
+      return normalizeBaseUrl(domain);
+    }
+    return `https://${domain.replace(/^\/+/, '')}`;
+  }
+
+  return normalizeBaseUrl(fallback);
+}
+
 export interface OAuthEndpoints {
   issuer: string;
   authorizationEndpoint: string;
@@ -26,6 +43,10 @@ export interface OAuthEndpoints {
   userInfoEndpoint: string;
   openIdConfigurationUrl: string;
   jwksUrl: string;
+  webIdentityUrl: string;
+  fedcmConfigUrl: string;
+  fedcmAccountsUrl: string;
+  fedcmIdAssertionUrl: string;
 }
 
 export function buildOAuthEndpoints(apiBase: string): OAuthEndpoints {
@@ -36,7 +57,11 @@ export function buildOAuthEndpoints(apiBase: string): OAuthEndpoints {
     tokenEndpoint: `${base}/oauth/token`,
     userInfoEndpoint: `${base}/oauth/userinfo`,
     openIdConfigurationUrl: `${base}/.well-known/openid-configuration`,
-    jwksUrl: `${base}/.well-known/jwks.json`
+    jwksUrl: `${base}/.well-known/jwks.json`,
+    webIdentityUrl: `${base}/.well-known/web-identity`,
+    fedcmConfigUrl: `${base}/fedcm/config.json`,
+    fedcmAccountsUrl: `${base}/fedcm/accounts`,
+    fedcmIdAssertionUrl: `${base}/fedcm/id_assertion`
   };
 }
 
diff --git a/apps/docs/lib/one-tap-examples.ts b/apps/docs/lib/one-tap-examples.ts
new file mode 100644
index 0000000..1a4812f
--- /dev/null
+++ b/apps/docs/lib/one-tap-examples.ts
@@ -0,0 +1,163 @@
+import type { OAuthExample } from '@/lib/oauth-examples';
+
+export interface OneTapUrls {
+  apiBase: string;
+  frontendBase: string;
+  widgetUrl: string;
+  fedcmConfigUrl: string;
+  webIdentityUrl: string;
+  projectName: string;
+}
+
+export function buildOneTapUrls(
+  apiBase: string,
+  frontendBase: string,
+  projectName = 'MVK ID'
+): OneTapUrls {
+  const base = apiBase.replace(/\/+$/, '');
+  const front = frontendBase.replace(/\/+$/, '');
+  return {
+    apiBase: base,
+    frontendBase: front,
+    widgetUrl: `${front}/sso-widget.js`,
+    fedcmConfigUrl: `${base}/fedcm/config.json`,
+    webIdentityUrl: `${base}/.well-known/web-identity`,
+    projectName
+  };
+}
+
+export function buildOneTapExamples(urls: OneTapUrls, clientIdPlaceholder = 'YOUR_CLIENT_ID'): OAuthExample[] {
+  const { apiBase, frontendBase, widgetUrl, fedcmConfigUrl, projectName } = urls;
+  const redirectUri = 'https://app.example.com/auth/callback';
+
+  return [
+    {
+      id: 'widget-script',
+      label: 'Виджет (script tag)',
+      language: 'html',
+      code: `<!-- Подключите на любой странице вашего сайта -->
+<script
+  src="${widgetUrl}"
+  data-client-id="${clientIdPlaceholder}"
+  data-idp-url="${apiBase}"
+  data-idp-frontend-url="${frontendBase}"
+  data-provider-name="${projectName}"
+  data-redirect-uri="${redirectUri}"
+  data-on-success="handleLendryLogin"
+></script>
+
+<script>
+  function handleLendryLogin(payload) {
+    // payload.token — id_token (FedCM) или токен из popup
+    // payload.method — 'fedcm' | 'popup'
+    console.log('Вход через', payload.method, payload.token);
+    // Отправьте token на ваш backend для проверки и создания сессии
+  }
+</script>`
+    },
+    {
+      id: 'fedcm-native',
+      label: 'FedCM (нативный API)',
+      language: 'javascript',
+      code: `// Работает в Chrome/Edge при поддержке IdentityCredential.
+// Пользователь должен быть залогинен на ${frontendBase} (FedCM cookie).
+
+async function loginWithFedCM() {
+  if (!('IdentityCredential' in window)) {
+    throw new Error('FedCM не поддерживается в этом браузере');
+  }
+
+  const credential = await navigator.credentials.get({
+    identity: {
+      providers: [{
+        configURL: '${fedcmConfigUrl}',
+        clientId: '${clientIdPlaceholder}'
+      }]
+    },
+    mediation: 'optional'
+  });
+
+  if (!credential?.token) {
+    throw new Error('Пользователь отменил вход или сессия IdP отсутствует');
+  }
+
+  return credential.token; // OIDC id_token
+}
+
+loginWithFedCM()
+  .then((idToken) => fetch('/api/auth/lendry', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ idToken })
+  }))
+  .catch(console.error);`
+    },
+    {
+      id: 'sdk-manual',
+      label: 'SDK — ручной вызов',
+      language: 'javascript',
+      code: `<script src="${widgetUrl}" data-auto-init="false"></script>
+<script>
+  LendryIdOneTap.init({
+    clientId: '${clientIdPlaceholder}',
+    idpUrl: '${apiBase}',
+    frontendUrl: '${frontendBase}',
+    providerName: '${projectName}',
+    redirectUri: '${redirectUri}',
+    scope: 'openid profile email'
+  });
+
+  window.addEventListener('lendry-sso-onetap-success', (event) => {
+    const { token, method, accessToken, idToken } = event.detail;
+    console.log(method, token ?? idToken ?? accessToken);
+  });
+</script>`
+    },
+    {
+      id: 'verify-backend',
+      label: 'Проверка токена на backend',
+      language: 'javascript',
+      code: `// Node.js — после получения id_token от FedCM или popup
+import jwt from 'jsonwebtoken';
+
+const ISSUER = '${apiBase}';
+const CLIENT_ID = '${clientIdPlaceholder}';
+
+function verifyIdToken(idToken) {
+  const payload = jwt.verify(idToken, process.env.IDP_JWT_SECRET, {
+    issuer: ISSUER,
+    audience: CLIENT_ID
+  });
+  return payload; // { sub, email, name, ... }
+}
+
+// Альтернатива: userinfo по access_token
+async function fetchProfile(accessToken) {
+  const res = await fetch('${apiBase}/oauth/userinfo', {
+    headers: { Authorization: \`Bearer \${accessToken}\` }
+  });
+  if (!res.ok) throw new Error('userinfo failed');
+  return res.json();
+}`
+    },
+    {
+      id: 'curl-fedcm',
+      label: 'FedCM endpoints (curl)',
+      language: 'bash',
+      code: `# Манифест FedCM
+curl -s ${apiBase}/.well-known/web-identity | jq
+
+# Конфигурация провайдера
+curl -s ${apiBase}/fedcm/config.json | jq
+
+# Список аккаунтов (нужна cookie lendry_fedcm_sess после входа на IdP)
+curl -s ${apiBase}/fedcm/accounts \\
+  -H "Cookie: lendry_fedcm_sess=..." \\
+  --include
+
+# Синхронизация FedCM cookie для уже залогиненного пользователя IdP
+curl -s -X POST ${apiBase}/fedcm/session/sync \\
+  -H "Authorization: Bearer ACCESS_TOKEN"`
+    }
+  ];
+}
diff --git a/apps/docs/next.config.ts b/apps/docs/next.config.ts
index 5171bdb..767f13e 100644
--- a/apps/docs/next.config.ts
+++ b/apps/docs/next.config.ts
@@ -17,6 +17,10 @@ const nextConfig: NextConfig = {
         source: '/oauth/:path*',
         destination: `${internalApiUrl}/oauth/:path*`
       },
+      {
+        source: '/fedcm/:path*',
+        destination: `${internalApiUrl}/fedcm/:path*`
+      },
       {
         source: '/.well-known/:path*',
         destination: `${internalApiUrl}/.well-known/:path*`
diff --git a/apps/frontend/app/admin/bots/page.tsx b/apps/frontend/app/admin/bots/page.tsx
index e8c96ae..37f7d9a 100644
--- a/apps/frontend/app/admin/bots/page.tsx
+++ b/apps/frontend/app/admin/bots/page.tsx
@@ -8,7 +8,7 @@ import { useAuth } from '@/components/id/auth-provider';
 import { useToast } from '@/components/id/toast-provider';
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
-import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from '@/components/ui/table';
+import { Table, TableBody, TableCell, TableContainer, TableHead, TableHeader, TableRow } from '@/components/ui/table';
 import {
   AdminBotMetrics,
   AdminUser,
@@ -107,7 +107,7 @@ export default function AdminBotsPage() {
         <p className="text-sm text-[#667085]">Найдено: {total}</p>
       </div>
 
-      <div className="overflow-hidden rounded-2xl border border-[#eceef4] bg-white">
+      <TableContainer className="rounded-2xl border border-[#eceef4] bg-white">
         <Table>
           <TableHeader>
             <TableRow>
@@ -191,7 +191,7 @@ export default function AdminBotsPage() {
             )}
           </TableBody>
         </Table>
-      </div>
+      </TableContainer>
 
       {totalPages > 1 ? (
         <div className="mt-4 flex items-center justify-center gap-2">
@@ -218,7 +218,7 @@ export default function AdminBotsPage() {
         <p className="mb-4 text-sm text-[#667085]">
           Пользователи IdP, связанные с Telegram-ботами (BotFather и боты пользователей). Роль: «Бот».
         </p>
-        <div className="overflow-hidden rounded-2xl border border-[#eceef4] bg-white">
+        <TableContainer className="rounded-2xl border border-[#eceef4] bg-white">
           <Table>
             <TableHeader>
               <TableRow>
@@ -270,7 +270,7 @@ export default function AdminBotsPage() {
               )}
             </TableBody>
           </Table>
-        </div>
+        </TableContainer>
       </div>
     </AdminShell>
   );
diff --git a/apps/frontend/app/admin/users/page.tsx b/apps/frontend/app/admin/users/page.tsx
index 85046c5..a355a56 100644
--- a/apps/frontend/app/admin/users/page.tsx
+++ b/apps/frontend/app/admin/users/page.tsx
@@ -11,7 +11,7 @@ import { useToast } from '@/components/id/toast-provider';
 import { Button } from '@/components/ui/button';
 import { Dialog, DialogContent, DialogHeader, DialogTitle } from '@/components/ui/dialog';
 import { Input } from '@/components/ui/input';
-import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from '@/components/ui/table';
+import { Table, TableBody, TableCell, TableContainer, TableHead, TableHeader, TableRow } from '@/components/ui/table';
 import { AdminPermission, AdminRole, AdminUser, adminDisableUserTotp, apiFetch, fetchUserTotpStatus } from '@/lib/api';
 import { getAdminLandingPath } from '@/lib/admin-access';
 import { DEFAULT_VERIFICATION_ICON, VERIFICATION_ICON_OPTIONS } from '@/lib/verification-icons';
@@ -324,7 +324,7 @@ export default function AdminUsersPage() {
         </div>
       </div>
 
-      <div className="overflow-x-auto rounded-[24px] border border-[#eceef4] bg-white">
+      <TableContainer className="rounded-[24px] border border-[#eceef4] bg-white">
         {loading ? (
           <div className="flex items-center justify-center gap-2 py-16 text-[#667085]">
             <Loader2 className="h-5 w-5 animate-spin" />
@@ -446,7 +446,7 @@ export default function AdminUsersPage() {
             </TableBody>
           </Table>
         )}
-      </div>
+      </TableContainer>
 
       <Dialog open={dialog === 'password'} onOpenChange={(open) => !open && setDialog(null)}>
         <DialogContent>
diff --git a/apps/frontend/components/chat/chat-image-lightbox.tsx b/apps/frontend/components/chat/chat-image-lightbox.tsx
index 80ed37a..ca10664 100644
--- a/apps/frontend/components/chat/chat-image-lightbox.tsx
+++ b/apps/frontend/components/chat/chat-image-lightbox.tsx
@@ -10,7 +10,7 @@ interface ChatImageLightboxProps {
   open: boolean;
   images: ChatMessage[];
   index: number;
-  mediaUrls: Record<string, { blobUrl: string; fileName?: string } | undefined>;
+  mediaUrls: Record<string, { blobUrl?: string; fileName?: string } | undefined>;
   onClose: () => void;
   onIndexChange: (index: number) => void;
   onDownload?: (message: ChatMessage) => void;
diff --git a/apps/frontend/components/chat/chat-media-album-grid.tsx b/apps/frontend/components/chat/chat-media-album-grid.tsx
index f9fc24c..4f7aeba 100644
--- a/apps/frontend/components/chat/chat-media-album-grid.tsx
+++ b/apps/frontend/components/chat/chat-media-album-grid.tsx
@@ -6,7 +6,7 @@ import { cn } from '@/lib/utils';
 
 interface ChatMediaAlbumGridProps {
   messages: ChatMessage[];
-  mediaUrls: Record<string, { blobUrl: string } | undefined>;
+  mediaUrls: Record<string, { blobUrl?: string } | undefined>;
   className?: string;
   onImageClick?: (message: ChatMessage, index: number) => void;
 }
diff --git a/apps/frontend/components/chat/chat-media-compose-dialog.tsx b/apps/frontend/components/chat/chat-media-compose-dialog.tsx
index 44fb7b8..ed4b13f 100644
--- a/apps/frontend/components/chat/chat-media-compose-dialog.tsx
+++ b/apps/frontend/components/chat/chat-media-compose-dialog.tsx
@@ -275,7 +275,7 @@ export function ChatMediaComposeDialog({
           type="file"
           className="hidden"
           multiple
-          accept="image/*,video/*,audio/*,.pdf,.doc,.docx,.xls,.xlsx,.zip,.rar,.7z,.txt"
+          accept="*/*"
           onChange={(event) => {
             const files = Array.from(event.target.files ?? []);
             if (files.length) onAddFiles(files);
diff --git a/apps/frontend/components/family/family-group-view.tsx b/apps/frontend/components/family/family-group-view.tsx
index 4e7ab5b..921b2df 100644
--- a/apps/frontend/components/family/family-group-view.tsx
+++ b/apps/frontend/components/family/family-group-view.tsx
@@ -152,10 +152,12 @@ interface PresignedUploadResponse {
 }
 
 interface LoadedChatMedia {
-  blobUrl: string;
-  expiresAt: number;
+  blobUrl?: string;
+  expiresAt?: number;
   fileName?: string;
   mimeType?: string;
+  status: 'loading' | 'ready' | 'error';
+  errorMessage?: string;
 }
 
 function formatMessageTime(value: string) {
@@ -318,6 +320,7 @@ export function FamilyGroupView({ groupId }: { groupId: string }) {
   const mediaRecorderRef = useRef<MediaRecorder | null>(null);
   const recordingStartedAtRef = useRef<number | null>(null);
   const mediaUrlsRef = useRef<Record<string, LoadedChatMedia>>({});
+  const mediaLoadInFlightRef = useRef<Set<string>>(new Set());
   const fileInputRef = useRef<HTMLInputElement>(null);
   const dragDepthRef = useRef(0);
 
@@ -678,7 +681,37 @@ export function FamilyGroupView({ groupId }: { groupId: string }) {
       if (!token || !activeRoomId || !message.storageKey) return;
       const storageKey = message.storageKey;
       const existing = mediaUrlsRef.current[storageKey];
-      if (!force && existing && !shouldRefreshMedia(existing.expiresAt)) return;
+      if (!force && existing?.status === 'ready' && existing.blobUrl && existing.expiresAt && !shouldRefreshMedia(existing.expiresAt)) {
+        return;
+      }
+      if (mediaLoadInFlightRef.current.has(storageKey) && !force) {
+        return;
+      }
+
+      if (message.isEncrypted && activeRoomIsE2E) {
+        if (peerKeyLoading) return;
+        if (!peerE2eKey || !user?.id || !message.content) {
+          setMediaUrls((current) => ({
+            ...current,
+            [storageKey]: {
+              ...current[storageKey],
+              status: 'error',
+              errorMessage: 'Не удалось расшифровать файл'
+            }
+          }));
+          return;
+        }
+      }
+
+      mediaLoadInFlightRef.current.add(storageKey);
+      setMediaUrls((current) => ({
+        ...current,
+        [storageKey]: {
+          ...current[storageKey],
+          status: 'loading',
+          errorMessage: undefined
+        }
+      }));
 
       let meta = parseMessageMetadata(message.metadataJson);
       let fileName = meta.fileName || message.content || undefined;
@@ -709,23 +742,50 @@ export function FamilyGroupView({ groupId }: { groupId: string }) {
               blobUrl,
               expiresAt: mediaExpiresAtMs(access.expiresAt),
               fileName,
-              mimeType
+              mimeType,
+              status: 'ready'
             }
           };
         });
-      } catch {
-        // ignore failed media loads in background
+      } catch (error) {
+        setMediaUrls((current) => ({
+          ...current,
+          [storageKey]: {
+            ...current[storageKey],
+            status: 'error',
+            errorMessage: error instanceof Error ? error.message : 'Не удалось загрузить файл'
+          }
+        }));
+      } finally {
+        mediaLoadInFlightRef.current.delete(storageKey);
       }
     },
-    [activeRoomId, activeRoomIsE2E, peerE2eKey, token, user?.id]
+    [activeRoomId, activeRoomIsE2E, peerE2eKey, peerKeyLoading, token, user?.id]
   );
 
+  const cacheUploadedMedia = useCallback((storageKey: string, file: File) => {
+    const blobUrl = createBlobObjectUrl(file);
+    setMediaUrls((current) => {
+      revokeBlobObjectUrl(current[storageKey]?.blobUrl);
+      return {
+        ...current,
+        [storageKey]: {
+          blobUrl,
+          expiresAt: Date.now() + 30 * 60_000,
+          fileName: file.name,
+          mimeType: file.type || resolveChatContentType(file),
+          status: 'ready'
+        }
+      };
+    });
+  }, []);
+
   useEffect(() => {
     if (!token || !activeRoomId) return;
     messages.forEach((message) => {
       if (message.storageKey) void loadChatMedia(message);
     });
-  }, [activeRoomId, loadChatMedia, messages, token]);
+  }, [activeRoomId, loadChatMedia, messages, peerE2eKey, peerKeyLoading, token]);
 
   useEffect(() => {
     if (!token || !activeRoomId) return;
@@ -733,7 +793,7 @@ export function FamilyGroupView({ groupId }: { groupId: string }) {
       messages.forEach((message) => {
         if (!message.storageKey) return;
         const cached = mediaUrlsRef.current[message.storageKey];
-        if (cached && shouldRefreshMedia(cached.expiresAt)) {
+        if (cached?.status === 'ready' && cached.expiresAt && shouldRefreshMedia(cached.expiresAt)) {
           void loadChatMedia(message, true);
         }
       });
@@ -1323,6 +1383,7 @@ export function FamilyGroupView({ groupId }: { groupId: string }) {
         token
       );
       appendMessage(message);
+      cacheUploadedMedia(presigned.storageKey, file);
       void loadGroup();
     } catch (error) {
       showToast(getApiErrorMessage(error, 'Не удалось отправить файл') ?? 'Ошибка');
@@ -1366,7 +1427,13 @@ export function FamilyGroupView({ groupId }: { groupId: string }) {
         peerE2eKey,
         encryptOutgoing
       });
-      uploaded.forEach((message) => appendMessage(message));
+      uploaded.forEach((message, index) => {
+        appendMessage(message);
+        const sourceFile = mediaComposer.items[index]?.file;
+        if (message.storageKey && sourceFile) {
+          cacheUploadedMedia(message.storageKey, sourceFile);
+        }
+      });
       mediaComposer.close();
       void loadGroup();
     } catch (error) {
@@ -1972,7 +2039,21 @@ export function FamilyGroupView({ groupId }: { groupId: string }) {
                           const media = mediaUrls[message.storageKey];
                           const meta = parseMessageMetadata(message.metadataJson);
                           const fileName = e2ePayload?.fileName || meta.fileName || message.content || 'Файл';
-                          if (!media?.blobUrl) {
+                          if (media?.status === 'error') {
+                            return (
+                              <div className="space-y-2 text-sm text-[#667085]">
+                                <p>{media.errorMessage ?? 'Не удалось загрузить файл'}</p>
+                                <button
+                                  type="button"
+                                  className="font-medium text-[#3390ec] hover:underline"
+                                  onClick={() => void loadChatMedia(message, true)}
+                                >
+                                  Повторить
+                                </button>
+                              </div>
+                            );
+                          }
+                          if (!media?.blobUrl || media.status === 'loading') {
                             return (
                               <div className="flex items-center gap-2 text-sm text-[#667085]">
                                 <Loader2 className="h-4 w-4 animate-spin" />
@@ -2275,7 +2356,7 @@ export function FamilyGroupView({ groupId }: { groupId: string }) {
         type="file"
         className="hidden"
         multiple
-        accept="image/*,video/*,audio/*,.pdf,.doc,.docx,.xls,.xlsx,.zip,.rar,.7z,.txt"
+        accept="*/*"
         onChange={(event) => {
           const files = Array.from(event.target.files ?? []);
           if (files.length) queueMediaFiles(files);
diff --git a/apps/frontend/components/family/mini-family-chat.tsx b/apps/frontend/components/family/mini-family-chat.tsx
index d6b266f..8e9df0d 100644
--- a/apps/frontend/components/family/mini-family-chat.tsx
+++ b/apps/frontend/components/family/mini-family-chat.tsx
@@ -1386,7 +1386,7 @@ export function MiniFamilyChat() {
         ref={fileInputRef}
         type="file"
         multiple
-        accept="image/*,audio/*,video/*,.pdf,.doc,.docx,.txt,.zip,.rar,.7z"
+        accept="*/*"
         className="hidden"
         onChange={(event) => {
           const files = Array.from(event.target.files ?? []);
diff --git a/apps/frontend/components/id/shell.tsx b/apps/frontend/components/id/shell.tsx
index 0bc037c..bde9d85 100644
--- a/apps/frontend/components/id/shell.tsx
+++ b/apps/frontend/components/id/shell.tsx
@@ -11,6 +11,8 @@ import { BrandLogo } from '@/components/id/brand-logo';
 import Link from 'next/link';
 import { cn } from '@/lib/utils';
 
+const MOBILE_HEADER_HEIGHT = 'calc(3.5rem + env(safe-area-inset-top))';
+
 export function IdShell({
   active,
   children,
@@ -25,10 +27,13 @@ export function IdShell({
   return (
     <FamilyOverlayProvider>
       <EmojiSpriteProvider />
-      <div className="min-h-screen overflow-x-hidden bg-white">
+      <div className="min-h-screen bg-white">
         <Sidebar active={active} />
         {!fullBleed ? (
-          <div className="fixed left-0 right-0 top-0 z-40 flex items-center justify-between border-b border-[#eceef4] bg-white/95 px-4 py-3 backdrop-blur lg:hidden">
+          <div
+            className="fixed left-0 right-0 top-0 z-40 flex h-[var(--mobile-header-height)] items-center justify-between border-b border-[#eceef4] bg-white/95 px-4 backdrop-blur lg:hidden"
+            style={{ ['--mobile-header-height' as string]: MOBILE_HEADER_HEIGHT, paddingTop: 'env(safe-area-inset-top)' }}
+          >
             <Link href="/" className="shrink-0">
               <BrandLogo size="sm" variant="dark" />
             </Link>
@@ -44,9 +49,10 @@ export function IdShell({
         </div>
         <main
           className={cn(
-            'pb-[calc(4.5rem+env(safe-area-inset-bottom))] lg:pb-8 lg:pl-[220px] lg:pr-8',
-            fullBleed ? 'px-0 pt-0 lg:pt-8' : 'px-0 pt-14 lg:pt-8'
+            'min-w-0 pb-[calc(4.5rem+env(safe-area-inset-bottom))] lg:pb-8 lg:pl-[220px] lg:pr-8',
+            fullBleed ? 'px-0 pt-0 lg:pt-8' : 'px-0 pt-[var(--mobile-header-height)] lg:pt-8'
           )}
+          style={fullBleed ? undefined : ({ ['--mobile-header-height' as string]: MOBILE_HEADER_HEIGHT } as React.CSSProperties)}
         >
           <div
             className={cn(
diff --git a/apps/frontend/components/ui/table.tsx b/apps/frontend/components/ui/table.tsx
index 462f1dc..3ebb40a 100644
--- a/apps/frontend/components/ui/table.tsx
+++ b/apps/frontend/components/ui/table.tsx
@@ -2,7 +2,21 @@ import * as React from 'react';
 import { cn } from '@/lib/utils';
 
 export function Table({ className, ...props }: React.TableHTMLAttributes<HTMLTableElement>) {
-  return <table className={cn('w-full caption-bottom text-sm', className)} {...props} />;
+  return <table className={cn('w-full min-w-[720px] caption-bottom text-sm', className)} {...props} />;
+}
+
+export function TableContainer({ className, children, ...props }: React.HTMLAttributes<HTMLDivElement>) {
+  return (
+    <div
+      className={cn(
+        'w-full max-w-full overflow-x-auto overscroll-x-contain [-webkit-overflow-scrolling:touch]',
+        className
+      )}
+      {...props}
+    >
+      {children}
+    </div>
+  );
 }
 
 export function TableHeader({ className, ...props }: React.HTMLAttributes<HTMLTableSectionElement>) {
diff --git a/apps/frontend/lib/chat-media.ts b/apps/frontend/lib/chat-media.ts
index af44638..be68857 100644
--- a/apps/frontend/lib/chat-media.ts
+++ b/apps/frontend/lib/chat-media.ts
@@ -31,7 +31,7 @@ const EXTENSION_TO_MIME: Record<string, string> = {
   rar: 'application/vnd.rar',
   '7z': 'application/x-7z-compressed',
   json: 'application/json',
-  xml: 'application/xml'
+  apk: 'application/vnd.android.package-archive'
 };
 
 const MIME_ALIASES: Record<string, string> = {
@@ -110,6 +110,7 @@ export function fileIconLabel(fileName?: string, mimeType?: string) {
   if (['xls', 'xlsx', 'csv'].includes(extension)) return 'XLS';
   if (['ppt', 'pptx'].includes(extension)) return 'PPT';
   if (['zip', 'rar', '7z'].includes(extension)) return 'ZIP';
+  if (extension === 'apk') return 'APK';
   if (extension) return extension.toUpperCase().slice(0, 4);
   return 'FILE';
 }
diff --git a/apps/frontend/next.config.ts b/apps/frontend/next.config.ts
index b7eeda9..6024e54 100644
--- a/apps/frontend/next.config.ts
+++ b/apps/frontend/next.config.ts
@@ -24,6 +24,10 @@ const nextConfig: NextConfig = {
         source: '/oauth/:path*',
         destination: `${internalApiUrl}/oauth/:path*`
       },
+      {
+        source: '/fedcm/:path*',
+        destination: `${internalApiUrl}/fedcm/:path*`
+      },
       {
         source: '/.well-known/:path*',
         destination: `${internalApiUrl}/.well-known/:path*`
diff --git a/apps/frontend/public/sso-widget.js b/apps/frontend/public/sso-widget.js
new file mode 100644
index 0000000..79ee6df
--- /dev/null
+++ b/apps/frontend/public/sso-widget.js
@@ -0,0 +1,274 @@
+(function lendrySsoWidget(global) {
+  'use strict';
+
+  var MESSAGE_TYPE = 'lendry-sso-onetap';
+  var DEFAULT_SCOPE = 'openid profile email';
+  var widgetRootId = 'lendry-sso-onetap-root';
+
+  function trimSlash(value) {
+    return String(value || '').replace(/\/+$/, '');
+  }
+
+  function resolveScriptElement() {
+    var current = global.document.currentScript;
+    if (current) return current;
+    var scripts = global.document.getElementsByTagName('script');
+    for (var i = scripts.length - 1; i >= 0; i -= 1) {
+      var src = scripts[i].getAttribute('src') || '';
+      if (src.indexOf('sso-widget.js') !== -1) {
+        return scripts[i];
+      }
+    }
+    return null;
+  }
+
+  function resolveIdpApiBase(script) {
+    var override = script && script.getAttribute('data-idp-url');
+    if (override) return trimSlash(override);
+    try {
+      var origin = new URL(script.src).origin;
+      return trimSlash(origin + '/idp-api');
+    } catch (_error) {
+      return '';
+    }
+  }
+
+  function resolveFrontendBase(script, idpApiBase) {
+    var override = script && script.getAttribute('data-idp-frontend-url');
+    if (override) return trimSlash(override);
+    try {
+      return new URL(script.src).origin;
+    } catch (_error) {
+      if (idpApiBase.indexOf('/idp-api') !== -1) {
+        return idpApiBase.replace(/\/idp-api$/, '');
+      }
+      return idpApiBase;
+    }
+  }
+
+  function resolveProviderName(script) {
+    return (script && script.getAttribute('data-provider-name')) || 'MVK ID';
+  }
+
+  function dispatchSuccess(payload, script) {
+    var callbackName = script && script.getAttribute('data-on-success');
+    if (callbackName && typeof global[callbackName] === 'function') {
+      global[callbackName](payload);
+    }
+    try {
+      global.dispatchEvent(new CustomEvent('lendry-sso-onetap-success', { detail: payload }));
+    } catch (_error) {
+      // IE fallback not required
+    }
+  }
+
+  function supportsFedCM() {
+    return 'IdentityCredential' in global && global.navigator && typeof global.navigator.credentials !== 'undefined';
+  }
+
+  function loginWithFedCM(idpApiBase, clientId) {
+    if (!supportsFedCM()) {
+      return Promise.resolve(null);
+    }
+
+    return global.navigator.credentials
+      .get({
+        identity: {
+          providers: [
+            {
+              configURL: idpApiBase + '/fedcm/config.json',
+              clientId: clientId
+            }
+          ]
+        },
+        mediation: 'optional'
+      })
+      .then(function (credential) {
+        if (!credential || typeof credential !== 'object') return null;
+        var token = credential.token;
+        if (!token) return null;
+        return {
+          token: token,
+          method: 'fedcm'
+        };
+      })
+      .catch(function (error) {
+        if (global.console && typeof global.console.warn === 'function') {
+          global.console.warn('[MVK ID] FedCM недоступен:', error);
+        }
+        return null;
+      });
+  }
+
+  function injectWidgetStyles() {
+    if (global.document.getElementById('lendry-sso-onetap-style')) return;
+    var style = global.document.createElement('style');
+    style.id = 'lendry-sso-onetap-style';
+    style.textContent =
+      '#' +
+      widgetRootId +
+      '{position:fixed;top:16px;right:16px;z-index:2147483000;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif}' +
+      '.lendry-sso-onetap-btn{display:flex;align-items:center;gap:10px;padding:10px 16px;border-radius:999px;border:1px solid #e4e8ef;background:#fff;color:#1f2430;font-size:14px;font-weight:600;line-height:1;cursor:pointer;box-shadow:0 8px 24px rgba(31,36,48,.12);transition:transform .18s ease,box-shadow .18s ease}' +
+      '.lendry-sso-onetap-btn:hover{transform:translateY(-1px);box-shadow:0 12px 28px rgba(31,36,48,.16)}' +
+      '.lendry-sso-onetap-btn:active{transform:translateY(0)}' +
+      '.lendry-sso-onetap-badge{display:inline-flex;align-items:center;justify-content:center;min-width:28px;height:28px;padding:0 8px;border-radius:999px;background:#111;color:#fff;font-size:12px;font-weight:700}';
+    global.document.head.appendChild(style);
+  }
+
+  function createWidget(providerName, onClick) {
+    injectWidgetStyles();
+    if (global.document.getElementById(widgetRootId)) return;
+
+    var root = global.document.createElement('div');
+    root.id = widgetRootId;
+
+    var button = global.document.createElement('button');
+    button.type = 'button';
+    button.className = 'lendry-sso-onetap-btn';
+    button.setAttribute('aria-label', 'Войти через ' + providerName);
+
+    var badge = global.document.createElement('span');
+    badge.className = 'lendry-sso-onetap-badge';
+    badge.textContent = 'ID';
+
+    var label = global.document.createElement('span');
+    label.textContent = 'Войти через ' + providerName;
+
+    button.appendChild(badge);
+    button.appendChild(label);
+    button.addEventListener('click', onClick);
+
+    root.appendChild(button);
+    global.document.body.appendChild(root);
+  }
+
+  function buildPopupUrl(frontendBase, clientId, origin, redirectUri, scope) {
+    var params = new URLSearchParams();
+    params.set('client_id', clientId);
+    params.set('redirect_uri', redirectUri);
+    params.set('response_type', 'code');
+    params.set('scope', scope || DEFAULT_SCOPE);
+    params.set('display', 'popup');
+    params.set('popup_origin', origin);
+    params.set('state', 'onetap_' + Math.random().toString(36).slice(2));
+    return frontendBase + '/auth/oauth/authorize?' + params.toString();
+  }
+
+  function openPopup(url, expectedOrigin, onToken) {
+    var width = 480;
+    var height = 640;
+    var left = Math.max(0, Math.round((global.screen.width - width) / 2));
+    var top = Math.max(0, Math.round((global.screen.height - height) / 2));
+    var features =
+      'popup=yes,width=' +
+      width +
+      ',height=' +
+      height +
+      ',left=' +
+      left +
+      ',top=' +
+      top +
+      ',noopener,noreferrer';
+
+    var popup = global.open(url, 'lendry_sso_onetap', features);
+    if (!popup) {
+      if (global.console && typeof global.console.error === 'function') {
+        global.console.error('[MVK ID] Не удалось открыть popup. Разрешите всплывающие окна.');
+      }
+      return function cleanup() {};
+    }
+
+    function handleMessage(event) {
+      if (!event || !event.data || event.data.type !== MESSAGE_TYPE) return;
+      if (expectedOrigin && event.origin !== expectedOrigin && event.origin !== trimSlash(expectedOrigin)) return;
+
+      cleanup();
+      onToken(event.data);
+    }
+
+    function cleanup() {
+      global.removeEventListener('message', handleMessage);
+      if (popup && !popup.closed) {
+        try {
+          popup.close();
+        } catch (_error) {
+          // ignore
+        }
+      }
+    }
+
+    global.addEventListener('message', handleMessage);
+    return cleanup;
+  }
+
+  function initOneTap(options) {
+    var script = resolveScriptElement();
+    var clientId = (options && options.clientId) || (script && script.getAttribute('data-client-id'));
+    if (!clientId) {
+      if (global.console && typeof global.console.error === 'function') {
+        global.console.error('[MVK ID] Укажите data-client-id в теге script или clientId в LendryIdOneTap.init().');
+      }
+      return;
+    }
+
+    var idpApiBase = trimSlash((options && options.idpUrl) || resolveIdpApiBase(script));
+    var frontendBase = trimSlash((options && options.frontendUrl) || resolveFrontendBase(script, idpApiBase));
+    var providerName = (options && options.providerName) || resolveProviderName(script);
+    var scope = (options && options.scope) || (script && script.getAttribute('data-scope')) || DEFAULT_SCOPE;
+    var redirectUri =
+      (options && options.redirectUri) ||
+      (script && script.getAttribute('data-redirect-uri')) ||
+      global.location.origin + '/auth/callback';
+
+    loginWithFedCM(idpApiBase, clientId).then(function (result) {
+      if (result && result.token) {
+        dispatchSuccess(
+          {
+            token: result.token,
+            method: 'fedcm'
+          },
+          script
+        );
+        return;
+      }
+
+      if (supportsFedCM()) {
+        return;
+      }
+
+      createWidget(providerName, function () {
+        var popupUrl = buildPopupUrl(frontendBase, clientId, global.location.origin, redirectUri, scope);
+        openPopup(popupUrl, frontendBase, function (payload) {
+          dispatchSuccess(
+            {
+              token: payload.token,
+              accessToken: payload.accessToken,
+              idToken: payload.idToken,
+              refreshToken: payload.refreshToken,
+              code: payload.code,
+              method: 'popup'
+            },
+            script
+          );
+        });
+      });
+    });
+  }
+
+  global.LendryIdOneTap = {
+    init: initOneTap,
+    loginWithFedCM: loginWithFedCM,
+    MESSAGE_TYPE: MESSAGE_TYPE
+  };
+
+  var scriptEl = resolveScriptElement();
+  if (scriptEl && scriptEl.getAttribute('data-auto-init') !== 'false') {
+    if (global.document.readyState === 'loading') {
+      global.document.addEventListener('DOMContentLoaded', function () {
+        initOneTap();
+      });
+    } else {
+      initOneTap();
+    }
+  }
+})(window);
diff --git a/apps/sso-core/src/app.module.ts b/apps/sso-core/src/app.module.ts
index ff2ad25..ae258b6 100644
--- a/apps/sso-core/src/app.module.ts
+++ b/apps/sso-core/src/app.module.ts
@@ -20,6 +20,7 @@ import { ProfileService } from './domain/profile.service';
 import { DocumentsService } from './domain/documents.service';
 import { AddressesService } from './domain/addresses.service';
 import { OAuthCoreService } from './domain/oauth-core.service';
+import { FedcmService } from './domain/fedcm.service';
 import { OAuthIssuerService } from './domain/oauth-issuer.service';
 import { OtpService } from './domain/otp.service';
 import { AdvancedAuthService } from './domain/advanced-auth.service';
@@ -74,6 +75,7 @@ import { BotFatherAssistantService } from './domain/bot/bot-father-assistant.ser
     DocumentsService,
     AddressesService,
     OAuthCoreService,
+    FedcmService,
     OAuthIssuerService,
     OtpService,
     AdvancedAuthService,
diff --git a/apps/sso-core/src/domain/auth-grpc.controller.ts b/apps/sso-core/src/domain/auth-grpc.controller.ts
index fd0f0b4..2251314 100644
--- a/apps/sso-core/src/domain/auth-grpc.controller.ts
+++ b/apps/sso-core/src/domain/auth-grpc.controller.ts
@@ -14,6 +14,7 @@ import { ProfileService } from './profile.service';
 import { DocumentsService } from './documents.service';
 import { AddressesService } from './addresses.service';
 import { OAuthCoreService } from './oauth-core.service';
+import { FedcmService } from './fedcm.service';
 import { OtpService } from './otp.service';
 import { AdvancedAuthService } from './advanced-auth.service';
 import { FamilyService } from './family.service';
@@ -42,6 +43,7 @@ export class AuthGrpcController {
     private readonly documents: DocumentsService,
     private readonly addresses: AddressesService,
     private readonly oauthCore: OAuthCoreService,
+    private readonly fedcm: FedcmService,
     private readonly otp: OtpService,
     private readonly advancedAuth: AdvancedAuthService,
     private readonly family: FamilyService,
@@ -831,6 +833,21 @@ export class AuthGrpcController {
     return this.oauthCore.getClientPublicInfo(command.clientId);
   }
 
+  @GrpcMethod('FedcmService', 'GetAccounts')
+  fedcmGetAccounts(command: { userId: string; sessionId: string }) {
+    return this.fedcm.getAccounts(command.userId, command.sessionId);
+  }
+
+  @GrpcMethod('FedcmService', 'IssueIdAssertion')
+  fedcmIssueIdAssertion(command: { userId: string; sessionId: string; clientId: string; accountId: string }) {
+    return this.fedcm.issueIdAssertion(command.userId, command.sessionId, command.clientId, command.accountId);
+  }
+
+  @GrpcMethod('FedcmService', 'GetClientMetadata')
+  fedcmGetClientMetadata(command: { clientId: string }) {
+    return this.fedcm.getClientMetadata(command.clientId);
+  }
+
   @GrpcMethod('OtpService', 'SendOtp')
   sendOtp(command: { target: string; channel: string; purpose: string; userId?: string }) {
     return this.otp.send(command);
diff --git a/apps/sso-core/src/domain/fedcm.service.ts b/apps/sso-core/src/domain/fedcm.service.ts
new file mode 100644
index 0000000..68c2dd0
--- /dev/null
+++ b/apps/sso-core/src/domain/fedcm.service.ts
@@ -0,0 +1,99 @@
+import { BadRequestException, Injectable, UnauthorizedException } from '@nestjs/common';
+import { PrismaService } from '../infra/prisma.service';
+import { OAuthCoreService } from './oauth-core.service';
+import { SessionService } from './session.service';
+import { assertHumanAccount, HUMAN_USER_WHERE } from './system-account.util';
+
+@Injectable()
+export class FedcmService {
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly session: SessionService,
+    private readonly oauthCore: OAuthCoreService
+  ) {}
+
+  async getAccounts(userId: string, sessionId: string) {
+    await this.assertUnlockedSession(userId, sessionId);
+
+    const user = await this.prisma.user.findFirst({
+      where: { id: userId, deletedAt: null, status: 'ACTIVE', ...HUMAN_USER_WHERE }
+    });
+    if (!user) {
+      return { accounts: [] };
+    }
+    assertHumanAccount(user, { asAuth: true });
+
+    const consents = await this.prisma.oAuthConsent.findMany({
+      where: { userId },
+      include: { client: { select: { clientId: true, isActive: true } } }
+    });
+
+    const approvedClients = consents
+      .filter((item) => item.client.isActive)
+      .map((item) => item.client.clientId);
+
+    const givenName = user.displayName.trim().split(/\s+/)[0] || user.displayName;
+
+    return {
+      accounts: [
+        {
+          id: user.id,
+          name: user.displayName,
+          given_name: givenName,
+          email: user.email ?? undefined,
+          picture: user.avatarUrl ?? undefined,
+          approved_clients: approvedClients
+        }
+      ]
+    };
+  }
+
+  async issueIdAssertion(userId: string, sessionId: string, clientId: string, accountId: string) {
+    if (accountId !== userId) {
+      throw new BadRequestException('account_id не совпадает с активной сессией');
+    }
+
+    await this.assertUnlockedSession(userId, sessionId);
+
+    const client = await this.prisma.oAuthClient.findUnique({
+      where: { clientId },
+      include: { scopes: { include: { scope: true } } }
+    });
+    if (!client?.isActive) {
+      throw new BadRequestException('OAuth-приложение не найдено или отключено');
+    }
+
+    const scopeSlugs = client.scopes.map((item) => item.scope.slug);
+    const scope = scopeSlugs.length > 0 ? scopeSlugs.join(' ') : 'openid profile email';
+
+    const consent = await this.oauthCore.checkConsent(userId, clientId, scope);
+    if (!consent.granted) {
+      await this.oauthCore.grantConsent(userId, clientId, scope);
+    }
+
+    const tokens = await this.oauthCore.issueFedcmTokens(userId, clientId, scopeSlugs.length > 0 ? scopeSlugs : ['openid', 'profile', 'email']);
+    return { token: tokens.idToken };
+  }
+
+  async getClientMetadata(clientId: string) {
+    const client = await this.prisma.oAuthClient.findUnique({ where: { clientId } });
+    if (!client?.isActive) {
+      throw new BadRequestException('OAuth-приложение не найдено или отключено');
+    }
+
+    return {
+      privacy_policy_url: 'https://id.lendry.ru/data',
+      terms_of_service_url: 'https://id.lendry.ru/data'
+    };
+  }
+
+  private async assertUnlockedSession(userId: string, sessionId: string) {
+    const state = await this.session.resolveSessionState(sessionId);
+    if (!state || state.userId !== userId) {
+      throw new UnauthorizedException('Сессия недействительна или истекла');
+    }
+    if (state.requiresPin) {
+      throw new UnauthorizedException('Требуется подтверждение PIN-кода');
+    }
+  }
+}
diff --git a/apps/sso-core/src/domain/oauth-core.service.ts b/apps/sso-core/src/domain/oauth-core.service.ts
index f8b019e..a2dc7f5 100644
--- a/apps/sso-core/src/domain/oauth-core.service.ts
+++ b/apps/sso-core/src/domain/oauth-core.service.ts
@@ -316,6 +316,10 @@ export class OAuthCoreService {
     return { clientId: client.clientId, name: client.name };
   }
 
+  async issueFedcmTokens(userId: string, clientId: string, scopes: string[]) {
+    return this.issueOAuthTokens(userId, clientId, scopes);
+  }
+
   private parseScopeSlugs(scope: string) {
     return [...new Set(scope.split(/\s+/).map((item) => item.trim()).filter(Boolean))];
   }
diff --git a/apps/sso-core/src/infra/chat-media.util.ts b/apps/sso-core/src/infra/chat-media.util.ts
index cf3b3cf..abd333c 100644
--- a/apps/sso-core/src/infra/chat-media.util.ts
+++ b/apps/sso-core/src/infra/chat-media.util.ts
@@ -5,8 +5,7 @@ const BLOCKED_CHAT_MEDIA_TYPES = new Set([
   'text/html',
   'application/xhtml+xml',
   'application/x-httpd-php',
-  'application/x-sh',
-  'application/x-msdownload'
+  'application/x-sh'
 ]);
 
 const EXTENSION_TO_MIME: Record<string, string> = {
@@ -40,7 +39,8 @@ const EXTENSION_TO_MIME: Record<string, string> = {
   rar: 'application/vnd.rar',
   '7z': 'application/x-7z-compressed',
   json: 'application/json',
-  xml: 'application/xml'
+  xml: 'application/xml',
+  apk: 'application/vnd.android.package-archive'
 };
 
 const MIME_ALIASES: Record<string, string> = {
@@ -53,7 +53,8 @@ const MIME_ALIASES: Record<string, string> = {
   'image/jpg': 'image/jpeg',
   'image/pjpeg': 'image/jpeg',
   'application/x-pdf': 'application/pdf',
-  'application/x-zip-compressed': 'application/zip'
+  'application/x-zip-compressed': 'application/zip',
+  'application/vnd.android.package-archive': 'application/vnd.android.package-archive'
 };
 
 export type ChatAttachmentKind = 'IMAGE' | 'AUDIO' | 'VOICE' | 'FILE';
@@ -75,38 +76,29 @@ export function normalizeChatContentType(contentType?: string | null, fileName?:
   return aliased || 'application/octet-stream';
 }
 
+function isBlockedDownloadType(normalized: string, fileName?: string | null) {
+  if (!BLOCKED_CHAT_MEDIA_TYPES.has(normalized)) {
+    return false;
+  }
+  const extension = extractFileExtension(fileName);
+  if (normalized === 'application/x-msdownload' && extension === 'apk') {
+    return false;
+  }
+  return true;
+}
+
 export function assertChatMediaContentType(contentType?: string | null, fileName?: string | null) {
   const normalized = normalizeChatContentType(contentType, fileName);
-  if (BLOCKED_CHAT_MEDIA_TYPES.has(normalized)) {
+  if (isBlockedDownloadType(normalized, fileName)) {
     throw new Error('Этот тип файла нельзя отправить в чат');
   }
 
   const [category] = normalized.split('/');
-  if (category === 'image' || category === 'audio' || category === 'video') {
+  if (category === 'image' || category === 'audio' || category === 'video' || category === 'text' || category === 'application') {
     return normalized;
   }
 
-  const allowedApplicationTypes = new Set([
-    'application/pdf',
-    'application/msword',
-    'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
-    'application/vnd.ms-excel',
-    'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
-    'application/vnd.ms-powerpoint',
-    'application/vnd.openxmlformats-officedocument.presentationml.presentation',
-    'application/zip',
-    'application/vnd.rar',
-    'application/x-7z-compressed',
-    'application/json',
-    'application/xml',
-    'application/octet-stream'
-  ]);
-
-  if (category === 'text' || allowedApplicationTypes.has(normalized)) {
-    return normalized;
-  }
-
-  throw new Error('Неподдерживаемый тип медиафайла для чата');
+  return 'application/octet-stream';
 }
 
 export function extensionForChatContentType(contentType: string, fileName?: string | null) {
@@ -156,6 +148,8 @@ export function extensionForChatContentType(contentType: string, fileName?: stri
       return 'ppt';
     case 'application/vnd.openxmlformats-officedocument.presentationml.presentation':
       return 'pptx';
+    case 'application/vnd.android.package-archive':
+      return 'apk';
     case 'text/plain':
       return 'txt';
     case 'text/csv':
diff --git a/install.sh b/install.sh
index 09a7e72..d037743 100644
--- a/install.sh
+++ b/install.sh
@@ -1816,6 +1816,12 @@ ${nginx_proxy_headers}
 ${nginx_proxy_headers}
     }
 
+    location /fedcm/ {
+        proxy_pass ${api_upstream}/fedcm/;
+        proxy_http_version 1.1;
+${nginx_proxy_headers}
+    }
+
 EOF
 }
 
diff --git a/package-lock.json b/package-lock.json
index b58ef33..690f8ad 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -35,11 +35,13 @@
         "@nestjs/swagger": "^11.2.3",
         "class-transformer": "^0.5.1",
         "class-validator": "^0.14.3",
+        "cookie-parser": "^1.4.7",
         "reflect-metadata": "^0.2.2",
         "rxjs": "^7.8.2"
       },
       "devDependencies": {
         "@nestjs/cli": "^11.0.14",
+        "@types/cookie-parser": "^1.4.10",
         "@types/node": "^24.10.1",
         "typescript": "^5.9.3"
       }
@@ -7276,6 +7278,39 @@
         "@babel/types": "^7.28.2"
       }
     },
+    "node_modules/@types/body-parser": {
+      "version": "1.19.6",
+      "resolved": "https://registry.npmjs.org/@types/body-parser/-/body-parser-1.19.6.tgz",
+      "integrity": "sha512-HLFeCYgz89uk22N5Qg3dvGvsv46B8GLvKKo1zKG4NybA8U2DiEO3w9lqGg29t/tfLRJpJ6iQxnVw4OnB7MoM9g==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "@types/connect": "*",
+        "@types/node": "*"
+      }
+    },
+    "node_modules/@types/connect": {
+      "version": "3.4.38",
+      "resolved": "https://registry.npmjs.org/@types/connect/-/connect-3.4.38.tgz",
+      "integrity": "sha512-K6uROf1LD88uDQqJCktA4yzL1YYAK6NgfsI0v/mTgyPKWsX1CnJ0XPSDhViejru1GcRkLWb8RlzFYJRqGUbaug==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
+    "node_modules/@types/cookie-parser": {
+      "version": "1.4.10",
+      "resolved": "https://registry.npmjs.org/@types/cookie-parser/-/cookie-parser-1.4.10.tgz",
+      "integrity": "sha512-B4xqkqfZ8Wek+rCOeRxsjMS9OgvzebEzzLYw7NHYuvzb7IdxOkI0ZHGgeEBX4PUM7QGVvNSK60T3OvWj3YfBRg==",
+      "dev": true,
+      "license": "MIT",
+      "peerDependencies": {
+        "@types/express": "*"
+      }
+    },
     "node_modules/@types/eslint": {
       "version": "9.6.1",
       "resolved": "https://registry.npmjs.org/@types/eslint/-/eslint-9.6.1.tgz",
@@ -7305,6 +7340,33 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/express": {
+      "version": "5.0.6",
+      "resolved": "https://registry.npmjs.org/@types/express/-/express-5.0.6.tgz",
+      "integrity": "sha512-sKYVuV7Sv9fbPIt/442koC7+IIwK5olP1KWeD88e/idgoJqDm3JV/YUiPwkoKK92ylff2MGxSz1CSjsXelx0YA==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "@types/body-parser": "*",
+        "@types/express-serve-static-core": "^5.0.0",
+        "@types/serve-static": "^2"
+      }
+    },
+    "node_modules/@types/express-serve-static-core": {
+      "version": "5.1.1",
+      "resolved": "https://registry.npmjs.org/@types/express-serve-static-core/-/express-serve-static-core-5.1.1.tgz",
+      "integrity": "sha512-v4zIMr/cX7/d2BpAEX3KNKL/JrT1s43s96lLvvdTmza1oEvDudCqK9aF/djc/SWgy8Yh0h30TZx5VpzqFCxk5A==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "@types/node": "*",
+        "@types/qs": "*",
+        "@types/range-parser": "*",
+        "@types/send": "*"
+      }
+    },
     "node_modules/@types/geojson": {
       "version": "7946.0.16",
       "resolved": "https://registry.npmjs.org/@types/geojson/-/geojson-7946.0.16.tgz",
@@ -7312,6 +7374,14 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/http-errors": {
+      "version": "2.0.5",
+      "resolved": "https://registry.npmjs.org/@types/http-errors/-/http-errors-2.0.5.tgz",
+      "integrity": "sha512-r8Tayk8HJnX0FztbZN7oVqGccWgw98T/0neJphO91KkmOzug1KkofZURD4UaD5uH8AqcFLfdPErnBod0u71/qg==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true
+    },
     "node_modules/@types/json-schema": {
       "version": "7.0.15",
       "resolved": "https://registry.npmjs.org/@types/json-schema/-/json-schema-7.0.15.tgz",
@@ -7375,6 +7445,22 @@
         "pg-types": "^2.2.0"
       }
     },
+    "node_modules/@types/qs": {
+      "version": "6.15.1",
+      "resolved": "https://registry.npmjs.org/@types/qs/-/qs-6.15.1.tgz",
+      "integrity": "sha512-GZHUBZR9hckSUhrxmp1nG6NwdpM9fCunJwyThLW1X3AyHgd9IlHb6VANpQQqDr2o/qQp6McZ3y/IA2rVzKzSbw==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true
+    },
+    "node_modules/@types/range-parser": {
+      "version": "1.2.7",
+      "resolved": "https://registry.npmjs.org/@types/range-parser/-/range-parser-1.2.7.tgz",
+      "integrity": "sha512-hKormJbkJqzQGhziax5PItDUTMAM9uE2XXQmM37dyd4hVM+5aVl7oVxMVUiVQn2oCQFN/LKCZdvSM0pFRqbSmQ==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true
+    },
     "node_modules/@types/react": {
       "version": "19.2.17",
       "resolved": "https://registry.npmjs.org/@types/react/-/react-19.2.17.tgz",
@@ -7395,6 +7481,29 @@
         "@types/react": "^19.2.0"
       }
     },
+    "node_modules/@types/send": {
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/@types/send/-/send-1.2.1.tgz",
+      "integrity": "sha512-arsCikDvlU99zl1g69TcAB3mzZPpxgw0UQnaHeC1Nwb015xp8bknZv5rIfri9xTOcMuaVgvabfIRA7PSZVuZIQ==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
+    "node_modules/@types/serve-static": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/@types/serve-static/-/serve-static-2.2.0.tgz",
+      "integrity": "sha512-8mam4H1NHLtu7nmtalF7eyBH14QyOASmcxHhSfEoRyr0nP/YdoesEtU+uSRvMe96TW/HPTtkoKqQLl53N7UXMQ==",
+      "dev": true,
+      "license": "MIT",
+      "peer": true,
+      "dependencies": {
+        "@types/http-errors": "*",
+        "@types/node": "*"
+      }
+    },
     "node_modules/@types/validator": {
       "version": "13.15.10",
       "resolved": "https://registry.npmjs.org/@types/validator/-/validator-13.15.10.tgz",
@@ -8561,6 +8670,25 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/cookie-parser": {
+      "version": "1.4.7",
+      "resolved": "https://registry.npmjs.org/cookie-parser/-/cookie-parser-1.4.7.tgz",
+      "integrity": "sha512-nGUvgXnotP3BsjiLX2ypbQnWoGUPIIfHQNZkkC668ntrzGWEZVW70HDEB1qnNGMicPje6EttlIgzo51YSwNQGw==",
+      "license": "MIT",
+      "dependencies": {
+        "cookie": "0.7.2",
+        "cookie-signature": "1.0.6"
+      },
+      "engines": {
+        "node": ">= 0.8.0"
+      }
+    },
+    "node_modules/cookie-parser/node_modules/cookie-signature": {
+      "version": "1.0.6",
+      "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.0.6.tgz",
+      "integrity": "sha512-QADzlaHc8icV8I7vbaJXJwod9HWYp8uCqf1xa4OfNu1T7JVxQIrUgOWtHdNDtPiywmFbiS12VjotIXLrKM3orQ==",
+      "license": "MIT"
+    },
     "node_modules/cookie-signature": {
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.2.2.tgz",
diff --git a/shared/proto/identity.proto b/shared/proto/identity.proto
index bc9c5e3..af21d59 100644
--- a/shared/proto/identity.proto
+++ b/shared/proto/identity.proto
@@ -13,6 +13,12 @@ service OAuthCoreService {
   rpc GetOAuthClientPublicInfo (GetOAuthClientPublicInfoRequest) returns (OAuthClientPublicInfo);
 }
 
+service FedcmService {
+  rpc GetAccounts (FedcmSessionRequest) returns (FedcmAccountsResponse);
+  rpc IssueIdAssertion (FedcmIdAssertionRequest) returns (FedcmIdAssertionResponse);
+  rpc GetClientMetadata (FedcmClientMetadataRequest) returns (FedcmClientMetadataResponse);
+}
+
 service OtpService {
   rpc SendOtp (SendOtpRequest) returns (OtpResponse);
   rpc VerifyOtp (VerifyOtpRequest) returns (OtpVerifyResponse);
@@ -107,6 +113,44 @@ message GetOAuthClientPublicInfoRequest {
   string clientId = 1;
 }
 
+message FedcmSessionRequest {
+  string userId = 1;
+  string sessionId = 2;
+}
+
+message FedcmAccount {
+  string id = 1;
+  string name = 2;
+  optional string given_name = 3;
+  optional string email = 4;
+  optional string picture = 5;
+  repeated string approved_clients = 6;
+}
+
+message FedcmAccountsResponse {
+  repeated FedcmAccount accounts = 1;
+}
+
+message FedcmIdAssertionRequest {
+  string userId = 1;
+  string sessionId = 2;
+  string clientId = 3;
+  string accountId = 4;
+}
+
+message FedcmIdAssertionResponse {
+  string token = 1;
+}
+
+message FedcmClientMetadataRequest {
+  string clientId = 1;
+}
+
+message FedcmClientMetadataResponse {
+  string privacy_policy_url = 1;
+  string terms_of_service_url = 2;
+}
+
 message CheckOAuthConsentRequest {
   string userId = 1;
   string clientId = 2;