http_timeout_link.dart

import 'package:graphql/client.dart';

class HttpTimeoutLink extends HttpLink {
  final Duration queryTimeout;
  final Duration mutationTimeout;

  HttpTimeoutLink({
    required String uri,
    required this.mutationTimeout,
    required this.queryTimeout,
  }) : super(uri);

  @override
  Stream<Response> request(Request request, [NextLink? forward]) async* {
    final stream = super.request(request, forward).first.timeout(
      request.isQuery ? queryTimeout : mutationTimeout,
      onTimeout: () => throw "Request timed out",
    );
    yield* stream.asStream();
  }
}

Thanks a lot! I was trying to find a solution for this problem.