Limitations

Forge legacy (≤ 1.12.2) is not implemented

The kit supports modern Forge only (1.13+). The legacy Forge install flow (universal JAR + FMLTweaker) needs its own metadata parsing, classpath layout, and tweaker arguments and is not in scope today.

If you call kit.versions.forge.list() for a 1.12.2 build the entry will appear, but attempting to install it will fail because the kit cannot find a modern install_profile.json inside the installer JAR.

NeoForge is not implemented

NeoForge's installer uses a slightly different profile schema. No resolver consumes it yet.

Online Microsoft authentication is out of scope

AuthModes.OFFLINE is fully implemented, including stable UUID derivation from the player name. AuthModes.ONLINE is supported as a pass-through — you provide the access token, UUID, username, and optional xuid / clientId / userType. The kit does not perform the Microsoft / Xbox Live OAuth flow itself; integrate that separately and pass the resulting token in.

Optional Forge processor outputs

Some early 1.13.x Forge installers declare an empty outputs map per processor. The kit verifies declared outputs by SHA-1; processors that succeed but produce no outputs entry are trusted by their exit code only. This matches the official installer's behaviour.

Known event-stream quirks

• download:started.expectedSize and download:progress.totalBytes are 0 when the manifest does not declare a size and the server does not return content-length. Treat zero as "unknown" in renderers — see guides/events.
• The runtime "latest across components" fallback in kit.versions.runtime.resolve only fires when preference: RuntimePreference.LATEST is set explicitly.