InstallForgeEvent

Fired continuously while Minecraft Forge is installing.

Fields

stageStage

Current installation phase of the Forge installer process.

gameVersionString

Target Minecraft version (e.g., 1.20.1).

loaderVersionString

Forge loader version being installed (e.g., 47.2.0).

Types

Stage

PREPARINGInitial environment checks and directory setup

DOWNLOADING_INSTALLERFetching required installer binaries

EXTRACTINGUnpacking Forge libraries into the target directory

RUNNING_INSTALLERExecuting the Forge installer process

WRITING_PROFILEUpdating the client launcher profile configuration

FINISHEDInstallation completed successfully

FAILEDInstallation encountered an error or was aborted

When it fires

ForgeInstallerInjector runs from Launcher.launchMinecraft(...) whenever LaunchConfiguration.loader is a ForgeLoader and the connectivity check earlier in the launch succeeded (Forge is never installed in offline mode - the launch just proceeds assuming Forge is already installed from a previous run). The stages fire in this order:

1. PREPARING: always first; creates the versions/libraries directories.
2. WRITING_PROFILE: only if launcher_profiles.json doesn’t already exist in the game directory. On repeat launches where it’s already there, this stage is skipped entirely.
3. DOWNLOADING_INSTALLER: before fetching the Forge installer JAR and verifying its SHA-1.
4. RUNNING_INSTALLER: before invoking the official Forge installer via reflection to do the actual client install.
5. Either FINISHED (install succeeded) or FAILED (a reflective invocation error occurred, followed by a thrown RuntimeException). Exactly one of these always fires last.

Note

EXTRACTING is defined in the Stage enum but is not currently posted anywhere - unpacking Forge’s own libraries happens inside the official Forge installer, which Minified invokes as an opaque step during RUNNING_INSTALLER rather than reimplementing itself. Don’t rely on EXTRACTING firing.