If you want to work on a package with multiple people, there are a few things that you need to take care of:
- Make sure that everyone who should edit the profile on mod.io or upload new vesions is a manager or administrator for the mod. On the mod.io page for your package, go to “Edit”, then “Team” to add team members and assign roles.
- Packages that you subscribe to through mod.io are not directly editable, and automatic updates would overwrite changes of the other when mod.io updates the package. No team member who edits the package should subscribe to it. Instead, you’ll need to share the files in another manner, for example by downloading the zip files from the mod.io page. Unzip the file into a new folder your package directory (configurable in the game settings). It will appear in the editor and you will be able to upload new versions if you are part of the team as described above.
- Coordination can become difficult when multiple people are working on the same files. Consider using Git to help (together with GitHub, for example). It works well for scripts and template files, but for save states and resource files like textures and models, you’ll still need to make sure that only one team member works on the same file at the same time.
You may also want to do playtesting sessions without making the package publicly available. You can upload your package to mod.io privately – no one else will be able too see it. Then, you can add your playtesters on the mod.io page for your package under Edit->Team.
If your testers shouldn’t be part of your team, or if you don’t want to add them manually, you also have another option: at the top of your private package’s page, there will be a notice telling you that it is not available publicly. It includes a preview link that you can share with your testers. With it, they can access the page of your private package. If they are logged in using their Steam account, they can subscribe and the package will be downloaded in-game.
Note that the preview link expires whenever you upload a new version of your package. But the subscriptions remain active, everyone who has subscribed will get the latest version automatically.