How to deploy an app to Steam using codemagic.yaml

Codemagic allows you to deploy your unity application to Steam.

This guide only applies to workflows configured with the codemagic.yaml.


  • A Unity Plus or Pro license. Your license is used to activate Unity on the Codemagic build server so the project can be built. The license is returned automatically once the workflow completes.
  • A Steam Partner account is required to publish to Steam.

Getting Started

SteamCMD is a tool used to upload builds to Steam. SteamCMD requires logging in to Steam and typically requires entering a Steam Guard code. There are two ways of solving this problem.

  1. Disable Steam Guard for the account doing the Steam upload. This is not recommended, as it makes the Steam account less secure.

  2. Use sentry files that are generated after logging in successfully to Steam. A Steam Guard code is not required when these sentry files are present on the build machine. Thus, we will save the sentry files as secure environment variables and place them at the correct path when the build starts.

Obtain the sentry files:

First, you need to install the SteamCMD.

   mkdir ~/Steam
   curl -sqL "" | tar zxvf - -C ~/Steam
   sudo apt-get install lib32gcc1
   mkdir ~/Steam 
   curl -sqL "" | tar zxvf - -C ~/Steam

Then log into Steam with the following, which will prompt for the Steam Guard code:

   ~/Steam/ +login steam $STEAM_USERNAME $STEAM_PASSWORD

You can now see the ssfn file in ~/Steam/ssfn******************* and the config.vdf file at ~/Steam/config/config.vdf.

Warning: Keep the sentry files private; do not check them into public source control.
  • Save the ssfn file name, ssfn file itself, and the config file to the respective environment variables in the Environment variables section in Codemagic UI, so they can be used in subsequent builds. Click Secure to encrypt the values. Note that binary files (i.e. ssfn, config.vdf) have to be base64 encoded locally before they can be saved to environment variables and decoded during the build.
Warning: When base64 encoding the files, make sure to remove the new lines \n of the encoded value before saving it to Codemagic.

If you don’t want to install the SteamCMD on your local machine to obtain the sentry files, you can use Codemagic machines to do so and then copy them into your local machine using the secure copy command scp.

   scp -P <port> builder@X.X.X.X ~/Library/Application\ Support/ssfn******************* .
   scp -P <port> builder@X.X.X.X ~/Library/Application\ Support/config/config.vdf .

Decode Sentry Files

In your workflow you need to base64 decode these files:

      - name: Decode Sentry files
        script: | 
          echo $CONFIG_FILE | base64 --decode > steam/config.vdf
          echo $SSFN_FILE | base64 --decode > steam/$SSFN_FILE_NAME

Copy Sentry files

And then copy them to the correct path:

      - name: Copy Sentry Files
        script: | 
          mkdir -p ~/Library/Application\ Support/Steam/config
          cp ~/clone/steam/$SSFN_FILE_NAME ~/Library/Application\ Support/Steam
          cp ~/clone/steam/config.vdf ~/Library/Application\ Support/Steam/config
      - name: Copy Sentry Files
        script: | 
          mkdir -p ~/Steam/config
          cp ~/clone/steam/$SSFN_FILE_NAME ~/Steam
          cp ~/clone/steam/config.vdf ~/Steam/config

Upload to Steam

To configure the upload to Steam, edit the following two files in the demo project:


These are standard VDF files required for uploading a build to Steam and require your application’s AppID, DepotID, and branch name for deployment.

And then use the script to publish your app to steam:

      - name: Upload Build to Steam
        script: | 
          ~/Steam/ +login $STEAM_USERNAME $STEAM_PASSWORD +run_app_build ~/clone/steam/app_build.vdf +quit

See the sample project here.