Forge (modern)

kit.versions.forge reads maven.minecraftforge.net/.../maven-metadata.xml and the promotions_slim.json mapping. Only modern Forge (1.13+) is supported — see Limitations for the legacy story.

import { Loaders, VersionPreference } from "@loontail/minecraft-kit";

const builds = await kit.versions.forge.list({ minecraftVersion: "1.20.1" });
const resolved = await kit.versions.forge.resolve({
  minecraftVersion: "1.20.1",
  preference: VersionPreference.RECOMMENDED,
});

Install flow

The Forge install is the most involved flow in the library:

1. Download the installer JAR to forge-installers/<full>-installer.jar.
2. Open the JAR and read install_profile.json and version.json.
3. Extract the embedded maven/ entries into libraries/<group>/<artifact>/<version>/.
4. Resolve the data tokens — [g:a:v] → library path, 'literal → literal, /path → extracted file, otherwise → string.
5. Plan downloads for every library declared by install_profile and version.json.
6. Plan processor invocations — for each processor entry in install_profile.processors that applies to the client side, resolve the classpath and substitute every {KEY} and [coord] token in the args.
7. Run downloads in parallel; install the runtime; run processors sequentially with the installed Mojang Java runtime; verify every declared output SHA-1.
8. Write versions/<forge-id>/<forge-id>.json so the launch composer can find the merged manifest.

Built-in processor tokens

Token	Resolved value
{SIDE}	"client"
{MINECRAFT_JAR}	<directory>/versions/<mc>/<mc>.jar
{MINECRAFT_VERSION}	<mc>
{ROOT}	<directory> (the per-target root)
{INSTALLER}	Absolute path to the downloaded installer JAR
{LIBRARY_DIR}	<directory>/libraries

[g:a:v[:c][@e]] references are resolved to absolute paths under LIBRARY_DIR.