Published on 2025-08-07T06:18:08Z

YandexCalendar bot

The YandexCalendar bot is a specialized web crawler from the Russian technology company Yandex. Its purpose is to retrieve public calendar files (such as .ics files) from websites. The data it collects is used to enhance Yandex's calendar applications with features like event discovery and synchronization. Its presence on your site indicates you are hosting public calendar data.

What is the YandexCalendar bot?

The YandexCalendar bot is a specialized user agent from Yandex that retrieves and processes calendar-related data from the web. It identifies itself in server logs with the user-agent string Mozilla/5.0 (compatible; YandexCalendar/1.0; +http://yandex.com/bots). Unlike a general web crawler, this bot's purpose is narrowly focused on calendar data, and it targets standard calendar file formats.

Why is the YandexCalendar bot crawling my site?

The YandexCalendar bot is visiting your website to access calendar files in standard formats like iCalendar (.ics). If your site contains these files or other calendar-related data, the bot may be crawling to retrieve this information. The frequency of visits depends on how often your calendar data is updated. The bot's visit is triggered by the presence of calendar data that could be integrated into Yandex's calendar services.

What is the purpose of the YandexCalendar bot?

The purpose of the YandexCalendar bot is to support Yandex's calendar services by automating the retrieval of public calendar data from the web. The data it collects can be integrated into Yandex's calendar applications, enhancing them with features like event suggestions and calendar synchronization. For website owners who want their events to be discoverable through Yandex's services, this crawling can increase the visibility of those events to Yandex users.

How do I block the YandexCalendar bot?

To prevent the YandexCalendar bot from accessing your calendar files, you can add a specific disallow rule to your robots.txt file. This is the standard method for managing crawler access.

To block this bot, add the following lines to your robots.txt file:

User-agent: YandexCalendar
Disallow: /

How to verify the authenticity of the user-agent operated by Yandex?

Reverse IP lookup technique

To verify user-agent authenticity, you can use host linux command two times with the IP address of the requester.
  1. > host IPAddressOfRequest
    This command returns the reverse lookup hostname (e.g., 4.4.8.8.in-addr.arpa.). 
  2. > host ReverseDNSFromTheOutputOfFirstRequest
If the output matches the original IP address and the domain is associated with a trusted operator (e.g., Yandex), the user-agent can be considered legitimate.

IP list lookup technique

Some operators provide a public list of IP addresses used by their crawlers. This list can be cross-referenced to verify a user-agent's authenticity. However, both operators and website owners may find it challenging to maintain an up-to-date list, so use this method with caution and in conjunction with other verification techniques.