GAMESLASHGameNetworkingSockets
By Valve
Valve’s game transport library uses connection handles with reliable and unreliable message delivery for custom multiplayer systems.
Start: The vcpkg registry provides gamenetworkingsockets. In a manifest project, use vcpkg add port gamenetworkingsockets, or consult the package page for classic mode.
Try: Study the ISteamNetworkingSockets reference for CreateListenSocketIP/ConnectByIPAddress and connection-handle-based messaging before designing your game protocol.
Important limitation: The open-source library and Steamworks SDK variant are not interchangeable. Valve’s relay network requires being a Steam partner and using the Steamworks SDK version. Installing the open-source package does not establish access to that service.
Documentation and sources: https://partner.steamgames.com/doc/api/ISteamNetworkingSockets · https://vcpkg.io/en/package/gamenetworkingsockets.html · https://partner.steamgames.com/doc/features/multiplayer/networking