feat: payload для /start в ботах.

lib/backend/modules/messages.dart

@@ -412,6 +412,11 @@ class CachedMessage {
     this.editHistory,
   });
 
+  bool get isBotStartMarker {
+    final control = attachments?.whereType<ControlAttachment>().firstOrNull;
+    return control != null && control.isBotStart;
+  }
+
   CachedMessage copyWith({
     String? status,
     bool? deleted,
@@ -809,6 +814,26 @@ class MessagesModule {
     return _api.sendRequest(Opcode.msgSend, payload);
   }
 
+  Future<Map<String, dynamic>?> sendBotStart(
+    int chatId,
+    String startPayload,
+  ) async {
+    final response = await _api.sendRequest(Opcode.msgSend, {
+      'chatId': chatId,
+      'message': {
+        'cid': DateTime.now().millisecondsSinceEpoch * -1,
+        'attaches': [
+          {
+            '_type': 'CONTROL',
+            'event': ControlAttachment.botStartedEvent,
+            'startPayload': startPayload,
+          },
+        ],
+      },
+    });
+    return _sentMessageMap(response);
+  }
+
   Future<String> _sendAndExtractMessageId(
     Map<String, dynamic> payload,
     String defaultError,

lib/core/cache/info_cache.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter/foundation.dart';
 
 import '../../backend/api.dart';
+import '../../models/bot_info.dart';
 import '../../models/chat_info.dart';
 import '../../models/contact_info.dart';
 import '../protocol/opcode_map.dart';
@@ -279,6 +280,36 @@ class PresenceFetch {
   }
 }
 
+class BotInfoFetch {
+  static final _cache = InfoCache<BotInfo>(
+    ttl: const Duration(minutes: 30),
+    fetcher: _fetch,
+  );
+
+  static Future<BotInfo?> get(int botId, {bool forceRefresh = false}) =>
+      _cache.get(botId, forceRefresh: forceRefresh);
+
+  static BotInfo? peek(int botId) => _cache.peek(botId);
+
+  static List<BotCommand> commandsOf(int botId) =>
+      _cache.peek(botId)?.commands ?? const [];
+
+  static void invalidate(int botId) => _cache.invalidate(botId);
+  static void clear() => _cache.clear();
+
+  static Future<BotInfo?> _fetch(int botId) async {
+    final api = _api;
+    if (api == null || api.state != SessionState.online) return null;
+    final resp = await api.sendRequest(Opcode.botInfo, {'botId': botId});
+    final data = resp.payload;
+    if (data is! Map) return null;
+    final info = BotInfo.fromPayload(botId, Map<String, dynamic>.from(data));
+    final contact = info.contact;
+    if (contact != null) ContactInfoFetch.putContact(botId, contact.raw);
+    return info;
+  }
+}
+
 class ChatInfoFetch {
   static final _cache = InfoCache<ChatInfo>(
     ttl: const Duration(minutes: 5),

lib/core/links/max_link.dart

@@ -3,8 +3,11 @@ enum MaxLinkKind { call, invite, user, content, public, auth, stickerSet }
 class MaxLink {
   final MaxLinkKind kind;
   final String url;
+  final String baseUrl;
+  final String? startPayload;
 
-  const MaxLink(this.kind, this.url);
+  const MaxLink(this.kind, this.url, {String? baseUrl, this.startPayload})
+    : baseUrl = baseUrl ?? url;
 
   static final RegExp _host = RegExp(
     r'^https?://(?:www\.)?max\.ru/(.+)$',
@@ -33,7 +36,8 @@ class MaxLink {
     final match = _host.firstMatch(url);
     if (match == null) return null;
 
-    final path = match.group(1)!.split('?').first.split('#').first;
+    final rest = match.group(1)!;
+    final path = rest.split('?').first.split('#').first;
     final segments = path
         .split('/')
         .where((s) => s.isNotEmpty)
@@ -59,6 +63,18 @@ class MaxLink {
 
     if (_reserved.contains(segments.first.toLowerCase())) return null;
     if (!_segment.hasMatch(segments.first)) return null;
-    return MaxLink(MaxLinkKind.public, url);
+    return MaxLink(
+      MaxLinkKind.public,
+      url,
+      baseUrl: 'https://max.ru/${segments.join('/')}',
+      startPayload: _startPayload(rest),
+    );
+  }
+
+  static String? _startPayload(String rest) {
+    final parts = rest.split('#').first.split('?');
+    if (parts.length < 2) return null;
+    final value = Uri.splitQueryString(parts[1])['start']?.trim();
+    return (value == null || value.isEmpty) ? null : value;
   }
 }

lib/frontend/screens/chats/chat_info_screen.dart

@@ -812,12 +812,7 @@ class _ChatInfoScreenState extends State<ChatInfoScreen>
             : int.tryParse(phone?.toString() ?? '');
         if (phoneInt != null && phoneInt > 0) {
           items.add(
-            _simpleInfoCard(
+            _simpleInfoCard(cs, l10n.loginPhoneNumber, formatPhone(phoneInt)!),
-              cs,
-              l10n.loginPhoneNumber,
-              formatPhone(phoneInt)!,
-              entities: true,
-            ),
           );
         }
         final bio =
@@ -825,7 +820,7 @@ class _ChatInfoScreenState extends State<ChatInfoScreen>
             (_contactData?.raw['about'] as String?);
         if (bio != null && bio.isNotEmpty) {
           if (items.isNotEmpty) items.add(const SizedBox(height: 8));
-          items.add(_simpleInfoCard(cs, l10n.chatInfoBio, bio, entities: true));
+          items.add(_simpleInfoCard(cs, l10n.chatInfoBio, bio));
         }
       }
     } else if (widget.chatType == 'CHANNEL') {
@@ -852,7 +847,6 @@ class _ChatInfoScreenState extends State<ChatInfoScreen>
     String label,
     String value, {
     bool isLink = false,
-    bool entities = false,
   }) {
     return GlossyPill(
       color: cs.surfaceContainerHigh,
@@ -869,20 +863,10 @@ class _ChatInfoScreenState extends State<ChatInfoScreen>
               style: TextStyle(color: cs.onSurfaceVariant, fontSize: 13),
             ),
             const SizedBox(height: 4),
-            if (entities)
             FormattedMessageText(
               text: value,
               ranges: const [],
               entityMode: TextEntityMode.copy,
-                style: TextStyle(
-                  color: cs.onSurface,
-                  fontSize: 16,
-                  fontWeight: FontWeight.w500,
-                ),
-              )
-            else
-              Text(
-                value,
               style: TextStyle(
                 color: isLink ? cs.primary : cs.onSurface,
                 fontSize: 16,
@@ -913,7 +897,12 @@ class _ChatInfoScreenState extends State<ChatInfoScreen>
                   style: TextStyle(color: cs.onSurfaceVariant, fontSize: 13),
                 ),
                 const SizedBox(height: 4),
-                Text(link, style: TextStyle(color: cs.primary, fontSize: 15)),
+                FormattedMessageText(
+                  text: link,
+                  ranges: const [],
+                  entityMode: TextEntityMode.copy,
+                  style: TextStyle(color: cs.primary, fontSize: 15),
+                ),
               ],
             ),
           ),

lib/frontend/screens/chats/chat_screen.dart

@@ -241,6 +241,7 @@ class ChatScreen extends StatefulWidget {
   final int? initialMessageTime;
   final String? commentPostId;
   final CachedMessage? postMessage;
+  final String? botStartPayload;
 
   const ChatScreen({
     super.key,
@@ -257,8 +258,21 @@ class ChatScreen extends StatefulWidget {
     this.initialMessageTime,
     this.commentPostId,
     this.postMessage,
+    this.botStartPayload,
   });
 
+  static final List<_ChatScreenState> _open = [];
+
+  static bool startBotInVisibleChat(int chatId, String startPayload) {
+    for (final screen in _open.reversed) {
+      if (screen.widget.chatId != chatId) continue;
+      if (!screen.mounted || !screen._isRouteCurrent) continue;
+      unawaited(screen._sendBotStart(startPayload));
+      return true;
+    }
+    return false;
+  }
+
   @override
   State<ChatScreen> createState() => _ChatScreenState();
 }
@@ -548,6 +562,7 @@ class _ChatScreenState extends State<ChatScreen>
   set _myId(int v) => _chatController.myId = v;
   CachedChat? chat;
   bool _peerIsBot = false;
+  bool _botStartRequested = false;
   ChatWallpaper? _wallpaper;
 
   bool get _composerFrosted =>
@@ -616,6 +631,7 @@ class _ChatScreenState extends State<ChatScreen>
     _previewChat = widget.channelSubscribed == false;
     _chatController.chatId = widget.chatId;
     _chatController.isMounted = () => mounted;
+    if (!_commentsMode) ChatScreen._open.add(this);
     unawaited(PushService.clearChatNotification(widget.chatId));
     unawaited(
       animojiModule
@@ -779,6 +795,9 @@ class _ChatScreenState extends State<ChatScreen>
     if (cached != null) _applyPeerKind(cached.isBot);
     final info = await ContactInfoFetch.get(peerId);
     if (info != null) _applyPeerKind(info.isBot);
+    if ((info ?? cached)?.isBot ?? false) {
+      unawaited(BotInfoFetch.get(peerId));
+    }
   }
 
   void _applyPeerKind(bool isBot) {
@@ -943,7 +962,44 @@ class _ChatScreenState extends State<ChatScreen>
       if (!mounted || !_isLoading) return;
       _shimmerController.repeat();
     });
-    _loadHistory();
+    unawaited(_loadHistory().then((_) => _sendPendingBotStart()));
+  }
+
+  bool get _isRouteCurrent {
+    if (!mounted) return false;
+    final route = ModalRoute.of(context);
+    return route == null || route.isCurrent;
+  }
+
+  Future<void> _sendPendingBotStart() async {
+    final payload = widget.botStartPayload;
+    if (payload == null || _botStartRequested || !mounted) return;
+    _botStartRequested = true;
+    await _sendBotStart(payload);
+  }
+
+  Future<void> _sendBotStart(String startPayload) async {
+    if (_myId == 0) {
+      final profile = await AppDatabase.loadActiveProfile();
+      if (!mounted) return;
+      _myId = profile?.id ?? 0;
+    }
+    try {
+      final sent = await messagesModule.sendBotStart(
+        widget.chatId,
+        startPayload,
+      );
+      if (!mounted) return;
+      if (sent == null) {
+        showCustomNotification(context, 'Не удалось запустить бота');
+        return;
+      }
+      await _persistOutgoing(
+        CachedMessage.fromPushPayload(_myId, widget.chatId, sent),
+      );
+    } catch (_) {
+      if (mounted) showCustomNotification(context, 'Не удалось запустить бота');
+    }
   }
 
   void _onLoadingFinished() {
@@ -1871,6 +1927,7 @@ class _ChatScreenState extends State<ChatScreen>
 
   @override
   void dispose() {
+    ChatScreen._open.remove(this);
     _chatController.persistSessionCache();
     if (_previewChat) {
       unawaited(chats.subscribeChat(api, widget.chatId, subscribe: false));

lib/frontend/widgets/formatted_message_text.dart

@@ -92,7 +92,7 @@ class _FormattedMessageTextState extends State<FormattedMessageText> {
     if (hasExplicitLink) return ranges;
     for (final match in linkPattern.allMatches(widget.text)) {
       final raw = match.group(0)!;
-      final target = raw.startsWith('www.') ? 'https://$raw' : raw;
+      final target = linkTarget(raw);
       ranges.add(
         FormatRange(
           format: TextFormat.link,

lib/frontend/widgets/link_text.dart

@@ -4,10 +4,14 @@ import 'package:flutter/material.dart';
 import '../../core/utils/link_opener.dart';
 
 final RegExp linkPattern = RegExp(
-  r'(https?://[^\s<>]+|www\.[^\s<>]+)',
+  r'(https?://[^\s<>]+'
+  r'|www\.[^\s<>]+'
+  r'|(?<![\w.@/-])max\.ru(?![\w.-])(?:/[^\s<>]*)?)',
   caseSensitive: false,
 );
 
+String linkTarget(String raw) => raw.contains('://') ? raw : 'https://$raw';
+
 class LinkText extends StatefulWidget {
   final String text;
   final TextStyle style;
@@ -46,7 +50,7 @@ class _LinkTextState extends State<LinkText> {
         spans.add(TextSpan(text: widget.text.substring(cursor, match.start)));
       }
       final url = match.group(0)!;
-      final target = url.startsWith('www.') ? 'https://$url' : url;
+      final target = linkTarget(url);
       final recognizer = TapGestureRecognizer()
         ..onTap = () => openExternalUrl(context, target);
       _recognizers.add(recognizer);

lib/frontend/widgets/max_link_handler.dart

@@ -33,7 +33,7 @@ Future<bool> tryHandleMaxLink(BuildContext context, String url) async {
     return _openStickerSet(context, link.url);
   }
 
-  final resolved = await LinkModule.resolve(api, link.url);
+  final resolved = await _resolve(link);
   if (!context.mounted) return true;
 
   switch (resolved) {
@@ -43,7 +43,7 @@ Future<bool> tryHandleMaxLink(BuildContext context, String url) async {
       showCustomNotification(context, message);
       return true;
     case ResolvedUser(:final contact):
-      _openContact(context, contact);
+      await _openContact(context, link, contact);
       return true;
     case ResolvedChat():
       await _openResolvedChat(context, link, resolved);
@@ -51,6 +51,13 @@ Future<bool> tryHandleMaxLink(BuildContext context, String url) async {
   }
 }
 
+Future<ResolvedLink?> _resolve(MaxLink link) async {
+  final resolved = await LinkModule.resolve(api, link.url);
+  if (link.startPayload == null || link.baseUrl == link.url) return resolved;
+  if (resolved is ResolvedChat || resolved is ResolvedUser) return resolved;
+  return LinkModule.resolve(api, link.baseUrl);
+}
+
 Future<bool> _openStickerSet(BuildContext context, String url) async {
   final path = url
       .replaceFirst(
@@ -71,12 +78,24 @@ Future<bool> _openStickerSet(BuildContext context, String url) async {
   return true;
 }
 
-void _openContact(BuildContext context, Map<dynamic, dynamic> contact) {
+Future<void> _openContact(
+  BuildContext context,
+  MaxLink link,
+  Map<dynamic, dynamic> contact,
+) async {
   final id = contact['id'];
   if (id is! int) {
     showCustomNotification(context, 'Не удалось открыть профиль');
     return;
   }
+
+  final startPayload = link.startPayload;
+  if (startPayload != null &&
+      await _startBotDialog(context, id, contact, startPayload)) {
+    return;
+  }
+  if (!context.mounted) return;
+
   unawaited(
     openContactDialogProfile(
       context,
@@ -87,6 +106,53 @@ void _openContact(BuildContext context, Map<dynamic, dynamic> contact) {
   );
 }
 
+Future<bool> _startBotDialog(
+  BuildContext context,
+  int botId,
+  Map<dynamic, dynamic> contact,
+  String startPayload,
+) async {
+  final profile = await AppDatabase.loadActiveProfile();
+  final myId = profile?.id ?? 0;
+  if (myId == 0) return false;
+
+  final chatId =
+      await AppDatabase.findDialogChatByParticipant(myId, botId) ??
+      (myId ^ botId);
+  if (chatId <= 0 || !context.mounted) return false;
+
+  _openChatAndStartBot(
+    context,
+    chatId: chatId,
+    name: _contactName(contact),
+    imageUrl: (contact['baseUrl'] as String?) ?? '',
+    chatType: 'DIALOG',
+    startPayload: startPayload,
+  );
+  return true;
+}
+
+void _openChatAndStartBot(
+  BuildContext context, {
+  required int chatId,
+  required String name,
+  required String imageUrl,
+  required String chatType,
+  required String startPayload,
+}) {
+  if (ChatScreen.startBotInVisibleChat(chatId, startPayload)) return;
+  pushSwipeable(
+    context,
+    (_) => ChatScreen(
+      chatId: chatId,
+      name: name,
+      imageUrl: imageUrl,
+      chatType: chatType,
+      botStartPayload: startPayload,
+    ),
+  );
+}
+
 Future<void> _openResolvedChat(
   BuildContext context,
   MaxLink link,
@@ -131,6 +197,19 @@ Future<void> _openResolvedChat(
     if (!context.mounted) return;
   }
 
+  final startPayload = link.startPayload;
+  if (startPayload != null && type == 'DIALOG') {
+    _openChatAndStartBot(
+      context,
+      chatId: id,
+      name: title,
+      imageUrl: icon,
+      chatType: type,
+      startPayload: startPayload,
+    );
+    return;
+  }
+
   pushSwipeable(
     context,
     (_) => ChatScreen(

lib/frontend/widgets/message_bubble.dart

@@ -752,6 +752,7 @@ class MessageBubble extends StatelessWidget {
     final contentType = _contentType;
 
     if (message.isControl) {
+      if (message.isBotStartMarker) return const SizedBox.shrink();
       const controlShape = BubbleShape.singleMiddle;
       return Padding(
         padding: EdgeInsets.only(

lib/models/attachment.dart

@@ -429,6 +429,8 @@ class LocationAttachment extends MessageAttachment {
 }
 
 class ControlAttachment extends MessageAttachment {
+  static const String botStartedEvent = 'botStarted';
+
   final String? event;
   final String? title;
   final List<int>? userIds;
@@ -444,6 +446,8 @@ class ControlAttachment extends MessageAttachment {
     this.userId,
   }) : super(type: AttachmentType.control);
 
+  bool get isBotStart => event == botStartedEvent;
+
   factory ControlAttachment.fromMap(Map<String, dynamic> map) {
     String? title = map['title']?.toString();
     if ((title == null || title.isEmpty) && map['shortMessage'] != null) {

lib/models/bot_info.dart

@@ -0,0 +1,48 @@
+import 'contact_info.dart';
+
+class BotCommand {
+  final String name;
+  final String? description;
+
+  const BotCommand({required this.name, this.description});
+
+  factory BotCommand.fromMap(Map map) => BotCommand(
+    name: map['name']?.toString() ?? '',
+    description: (map['description'] as String?)?.trim().isNotEmpty == true
+        ? (map['description'] as String).trim()
+        : null,
+  );
+
+  String get slash => '/$name';
+}
+
+class BotInfo {
+  final int botId;
+  final List<BotCommand> commands;
+  final ContactInfo? contact;
+
+  const BotInfo({required this.botId, required this.commands, this.contact});
+
+  factory BotInfo.fromPayload(int botId, Map<String, dynamic> payload) {
+    final rawCommands = payload['commands'];
+    final commands = <BotCommand>[];
+    if (rawCommands is List) {
+      for (final c in rawCommands.whereType<Map>()) {
+        final command = BotCommand.fromMap(c);
+        if (command.name.isNotEmpty) commands.add(command);
+      }
+    }
+    final rawContact = payload['contact'];
+    return BotInfo(
+      botId: botId,
+      commands: commands,
+      contact: rawContact is Map
+          ? ContactInfo.fromMap(Map<String, dynamic>.from(rawContact))
+          : null,
+    );
+  }
+
+  String? get description => contact?.raw['description'] as String?;
+
+  String? get link => contact?.raw['link'] as String?;
+}

test/bot_start_control_test.dart

@@ -0,0 +1,99 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:komet/backend/modules/messages.dart';
+import 'package:komet/models/attachment.dart';
+import 'package:komet/models/bot_info.dart';
+
+void main() {
+  group('botStarted control message', () {
+    CachedMessage parse(Map<String, dynamic> message) =>
+        CachedMessage.fromPushPayload(1001, 2002, message);
+
+    test('is a control message and a start marker', () {
+      final message = parse({
+        'id': '3003',
+        'time': 1700000000000,
+        'type': 'USER',
+        'sender': 1001,
+        'text': 'abc123',
+        'attaches': [
+          {'_type': 'CONTROL', 'event': 'botStarted'},
+        ],
+      });
+
+      expect(message.isControl, isTrue);
+      expect(message.isBotStartMarker, isTrue);
+    });
+
+    test('other control events are not start markers', () {
+      final message = parse({
+        'id': '3004',
+        'time': 1700000000000,
+        'type': 'USER',
+        'sender': 1001,
+        'attaches': [
+          {'_type': 'CONTROL', 'event': 'add', 'userIds': [1002]},
+        ],
+      });
+
+      expect(message.isControl, isTrue);
+      expect(message.isBotStartMarker, isFalse);
+    });
+
+    test('a plain message is neither', () {
+      final message = parse({
+        'id': '3005',
+        'time': 1700000000000,
+        'type': 'USER',
+        'sender': 1001,
+        'text': 'привет',
+        'attaches': const [],
+      });
+
+      expect(message.isControl, isFalse);
+      expect(message.isBotStartMarker, isFalse);
+    });
+
+    test('the event name used on the wire stays stable', () {
+      expect(ControlAttachment.botStartedEvent, 'botStarted');
+    });
+  });
+
+  group('BotInfo', () {
+    test('parses commands and the bot contact', () {
+      final info = BotInfo.fromPayload(4004, {
+        'commands': [
+          {'botId': 4004, 'name': 'start', 'description': 'Главное меню'},
+          {'botId': 4004, 'name': 'stats', 'description': '  '},
+          {'botId': 4004, 'description': 'без имени'},
+        ],
+        'contact': {
+          'id': 4004,
+          'names': [
+            {'name': 'Тестовый бот', 'type': 'ONEME'},
+          ],
+          'options': ['BOT'],
+          'description': 'Описание бота',
+          'link': 'https://max.ru/id100000000001_bot',
+        },
+      });
+
+      expect(info.botId, 4004);
+      expect(info.commands.map((c) => c.name), ['start', 'stats']);
+      expect(info.commands.first.slash, '/start');
+      expect(info.commands.first.description, 'Главное меню');
+      expect(info.commands.last.description, isNull);
+      expect(info.contact?.isBot, isTrue);
+      expect(info.contact?.displayName, 'Тестовый бот');
+      expect(info.description, 'Описание бота');
+      expect(info.link, 'https://max.ru/id100000000001_bot');
+    });
+
+    test('tolerates a payload without commands or contact', () {
+      final info = BotInfo.fromPayload(4005, const {});
+
+      expect(info.commands, isEmpty);
+      expect(info.contact, isNull);
+      expect(info.link, isNull);
+    });
+  });
+}

test/max_link_test.dart

@@ -0,0 +1,92 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:komet/core/links/max_link.dart';
+import 'package:komet/frontend/widgets/link_text.dart';
+
+void main() {
+  group('linkPattern', () {
+    List<String> matches(String text) =>
+        linkPattern.allMatches(text).map((m) => m.group(0)!).toList();
+
+    test('picks up a bare max.ru link inside plain text', () {
+      expect(
+        matches('Ваша ссылка 👇\nmax.ru/id100000000001_bot?start=abc123\n'),
+        ['max.ru/id100000000001_bot?start=abc123'],
+      );
+      expect(matches('зайди на max.ru и посмотри'), ['max.ru']);
+    });
+
+    test('still picks up schemed and www links', () {
+      expect(matches('https://max.ru/somebot?start=x'), [
+        'https://max.ru/somebot?start=x',
+      ]);
+      expect(matches('www.max.ru/somebot'), ['www.max.ru/somebot']);
+    });
+
+    test('does not match look-alike hosts or emails', () {
+      expect(matches('evil.max.ru/phish'), isEmpty);
+      expect(matches('max.ru.evil.com/phish'), isEmpty);
+      expect(matches('bot@max.ru'), isEmpty);
+      expect(matches('max.rules/somebot'), isEmpty);
+    });
+
+    test('linkTarget adds a scheme only when missing', () {
+      expect(linkTarget('max.ru/somebot'), 'https://max.ru/somebot');
+      expect(linkTarget('www.max.ru/somebot'), 'https://www.max.ru/somebot');
+      expect(linkTarget('http://max.ru/somebot'), 'http://max.ru/somebot');
+      expect(linkTarget('https://max.ru/somebot'), 'https://max.ru/somebot');
+    });
+
+    test('a bare link is parsed as a max link once normalized', () {
+      final link = MaxLink.parse(linkTarget('max.ru/somebot?start=abc123'));
+
+      expect(link!.kind, MaxLinkKind.public);
+      expect(link.startPayload, 'abc123');
+    });
+  });
+
+  group('MaxLink start payload', () {
+    test('parses a bot start link over http', () {
+      final link = MaxLink.parse('http://max.ru/id100000000001bot?start=abc123');
+
+      expect(link, isNotNull);
+      expect(link!.kind, MaxLinkKind.public);
+      expect(link.startPayload, 'abc123');
+      expect(link.baseUrl, 'https://max.ru/id100000000001bot');
+      expect(link.url, 'http://max.ru/id100000000001bot?start=abc123');
+    });
+
+    test('decodes the payload and ignores a trailing fragment', () {
+      final link = MaxLink.parse(
+        'https://www.max.ru/somebot?start=a%20b&ref=x#top',
+      );
+
+      expect(link!.startPayload, 'a b');
+      expect(link.baseUrl, 'https://max.ru/somebot');
+    });
+
+    test('keeps the payload empty for links without one', () {
+      expect(MaxLink.parse('https://max.ru/somebot')!.startPayload, isNull);
+      expect(
+        MaxLink.parse('https://max.ru/somebot?start=')!.startPayload,
+        isNull,
+      );
+      expect(
+        MaxLink.parse('https://max.ru/somebot?other=1')!.startPayload,
+        isNull,
+      );
+    });
+
+    test('leaves other link kinds untouched', () {
+      final invite = MaxLink.parse('https://max.ru/join/AbCdEf?start=x');
+
+      expect(invite!.kind, MaxLinkKind.invite);
+      expect(invite.startPayload, isNull);
+      expect(invite.baseUrl, invite.url);
+    });
+
+    test('still rejects non-max links', () {
+      expect(MaxLink.parse('https://example.com/somebot?start=x'), isNull);
+      expect(MaxLink.parse('https://max.ru/?start=x'), isNull);
+    });
+  });
+}