What is the A2S query protocol?

A2S is a popular UDP-based game server query protocol that Valve Software maintains as a part of the Steam SDK. Many game engines support A2S natively, but if yours doesn’t, you can add support for A2S manually by using one of the A2S libraries for your preferred language (e.g., go-a2s for Golang, QueryMaster for C#).

Visit the Valve Software wiki page for server queries to learn more about the technical details of the A2S protocol, including the protocol specification, response body format, and a list of implementations in various languages.

To integrate a manual A2S implementation with Clanforge, you must configure at least the following variables:

• Players

• Max players

• Map

• Server name

It’s important to ensure that the values reported for Players and Max. Players in A2S_INFO responses are accurate. Clanforge uses these values to calculate and monitor resource usages on the machine. If the values are inaccurate or invalid (that is, in the wrong format), we won’t be able to manage resources properly, which could cause errors, game server crashes, or sub-optimal performance. We recommend that you also provide accurate maptype data, which allows us to report crashes by maptype.

You can use QStat to retrieve information from your game servers once you’ve added support for A2S (or another supported query protocol).