Counter-Strike: Source

Counter-Strike: Source runs over TCP+UDP and persists its server files under /home/steam/css. Swarm Hosts waits for a Source query response on the UDP game port before marking the deployment ready, and it publishes the same base port number on both protocols instead of splitting TCP and UDP across two different host ports.

Quick Facts

  • Image: swarmhost/games:cs-source-game-runtime-detected-stable-2026.05.15-owned-data-dir
  • Persistent data: /home/steam/css
  • Default ports: 27015/tcp, 27015/udp on the same published port number

Current Readiness

Counter-Strike: Source is in the public launch catalog. The latest validation on June 28, 2026 used a disposable managed-relay deployment of the current CSS image, confirmed Source-query responses through the relay UDP endpoint for five minutes, and verified the platform public probe reported both relay TCP and Source-query UDP as reachable.

Launch Notes

  1. Choose Counter-Strike: Source in the launch flow.
  2. Set SERVER_NAME, MAP, and any password/RCON values you need.
  3. First boot installs the dedicated server through SteamCMD, so expect a longer startup than a restart.

Connect

Players can join through the in-game server browser or the client console with:

connect <host>:<published-port>

If you see different TCP and UDP host port numbers for CSS, that deployment shape is wrong. Source servers expect the -port value to stay aligned across the UDP game/query traffic and the TCP RCON listener.