Mods repository

From VCMI Project Wiki
Jump to: navigation, search

This article will introduce you to new VCMI mod repository system and explain how new mods can be added there.

How mod repository work

Where files are hosted

Mods list hosted under main VCMI organization: vcmi-mods-repository.

Each mod hosted in it's own repository under separate organization vcmi-mods. This way if engine become more popular in future we can create separate teams for each mod and accept as many people as needed.

Why Git / GitHub?

It's solve a lot of problems:

  • Engine developers get control over all mods and can easily update them without adding extra burden for modders / mod maintainers.
  • With tools such as GitHub Desktop it's easy for non-programmers to contribute.
  • Forward and backward compatibility. Stable releases of game use compatible version of mods while users of daily builds will be able to test mods supporting bleeding edge features.
  • Tracking of changes for repository and mods. It's not big deal now, but once we have scripting it's will be important to keep control over what code included in mods.
  • GitHub also create ZIP archives for us so mods will be stored uncompressed and version can be identified by commit hash.

On backward compatibility

Our mod list in vcmi-mods-repository had "develop" as primary branch. Daily builds of VCMI use mod list file from this branch.

Once VCMI get stable release there will be branching into "1.00", "1.01", etc. Launcher of released version will request mod list for particular version.

Same way we can also create special stable branch for every mod under "vcmi-mods" organization umbrella once new stable version is released. So this way it's will be easier to maintain two versions of same mod: for stable and latest version.

Redirect server

Launcher will request specific version of JSON mod list from our server:

Our server redirect requests to github: -> ->

Same happen when launcher will request mods: ->

This way in case of any problems with GitHub we can easily change the way mods are delivered.

Getting mod into repository

Getting into vcmi-mods organization

Before your mod can be accepted into official mod list you need to get it into repository under "vcmi-mods" organization umbrella. To do this contact one of mod repository maintainers. If needed you can get own team within "vcmi-mods" organization.

Link to our mod will looks like that:

Rules of repository

Allowed name for mod identifier

For sanity reasons mod identifier must only contain lower-case English characters, numbers and hyphens.


Sub-mods can be named as you like, but we strongly encourage everyone to use proper identifiers for them as well.

Rewriting History

Once you submitted certain commit into official mod list you are not allowed to rewrite history before that commit. This way we can make sure that VCMI launcher will always be able to download older version of any mod.

Branches such as "develop" or stable branches like "1.00" should be marked as protected on GitHub.

Submitting mods to repository

Once mod ready for general public maintainer to make PR to vcmi-mods-repository.


Right now main requirements for a mod to be accepted into VCMI mods list are:

  • Mod must be complete. For work-in-progress mods it is better to use other way of distribution.
  • Mod must met some basic quality requirements. Having high-quality content is always preferable.
  • Mod must not contain any errors detectable by validation (console message you may see during loading)
  • Music files must be in Ogg/Vorbis format (*.ogg extension)