If you're just browsing the website, the server do collect the same basic information that most websites collect. The informations includes the internet browser type, language preference, referring site and the date and time of each request. The server also collect potentially personally-identifying information like Internet Protocol (IP) addresses.
If you're using the robots.txt viewer extension on google chrome, the server do collect some base informations like if you're browsing the website.
In addition, the following data is collected on a request:
The IP address in encrypted form is used for identification to locate and block excessive API requests. The user agent can also be used to determine the origin of excessive requests.