Publishing to the mod index

The launcher's mod browser reads one index of published mods, published with this site at https://veradictus.github.io/Thief3-Decomp/modindex/index.json. It is built from one file per mod in this repository, modindex/mods/<id>.json. To list your mod, open a pull request that adds that file.

The index lists mods; it does not host them. The packages stay on your own release page.

1. Release the package

Upload the .t3mod somewhere with a stable https:// address. A GitHub release is the usual place, and the mod template's workflow puts it there.

Don't replace a file once it is published. The index records each file's size and SHA-256, and the launcher refuses a download that does not match. Publish a new version instead.

2. Write the entry

modindex/mods/<id>.json describes the mod and lists its versions, newest first:

{
  "id": "my-mod",
  "name": "My Mod",
  "description": "What the mod does, in one paragraph.",
  "authors": ["Your Name"],
  "homepage": "https://github.com/you/my-mod",
  "license": "MIT",
  "tags": ["gameplay"],
  "versions": [
    {
      "version": "1.0.0",
      "url": "https://github.com/you/my-mod/releases/download/v1.0.0/my-mod-1.0.0.t3mod",
      "sha256": "…64 hex digits…",
      "size": 48213,
      "released": "2026-09-01",
      "api": 1
    }
  ]
}

• id, name, description, authors, homepage, license and tags repeat your mod.json.
• Per version: sha256 and size (in bytes) are those of the .t3mod file; python tools/t3mod.py info <file> prints the SHA-256. released is the date, YYYY-MM-DD.
• api, requires and conflicts repeat that version's mod.json, so that the browser can check them before it downloads anything.

The file is one entry of the index's mods list; the specification describes the index in full.

3. Open a pull request

Fork this repository, add the file, and open a pull request. CI checks it with tools/modindex.py validate. You can run the same checks first, from a checkout:

python tools/modindex.py validate   # the entries are well formed
python tools/modindex.py verify     # also downloads each new version and compares it with its manifest

After the pull request is merged, the site's workflow rebuilds the index and publishes it, and the mod shows in every launcher's browser.

New versions

Upload the new package, add a new element at the top of versions, and open a pull request. Keep the older versions in the list.

Rules

• The file name, the entry's id and the package's id are the same.
• Every URL is https://.
• The package holds only your own work: no files from the game.
• The description says what the mod does, and what else it needs (such as Sneaky Upgrade).