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Cauldron Documentation
🚧 This project and documentation is under construction and may be inaccurate. Packages and APIS may not be ready or available. 🚧

Launcher

These commands launch instances of Minecraft.

start

Section titled “start”

Install and launch an instance of Minecraft.

Usage:

Terminal window
cauldroncli start [options]

Options:

  • -v <version> --mc_version <version>: Minecraft Version (Required unless launching a saved modpack)
  • -l <loader> --mc_loader <loader>: Loader: vanilla, forge, fabric or neoforge (Default: vanilla)
  • -x <version> --mc_loader_version <version>: Loader Version (Default: recommended version)
  • -n <name> --name <name>: Instance Name. Also used as the modpack name
  • -m <token> --account <token>: Minecraft Access Token. See Accounts
  • -o <overrides> --overrides <overrides>: Launch overrides as CSV. See Overrides
  • --curseforge_mods <mods>: CSV of CurseForge mod slugs to install
  • --modrinth_mods <mods>: CSV of Modrinth mod slugs to install
  • -c --cache: Use the existing modpack called <name> instead of rebuilding it from the mod flags
  • -i --dry: Install but don’t launch (Default: false)
  • -g --headless: Skip interactive elements
  • -d --debug: Output extra debugging information

The game is installed (if needed) and launched. Once the game starts, its log is shown in the terminal until the game closes (unless --dry or --headless is used).

Each instance runs in its own folder at sessions/<name> in the Cauldron folder. If --name is not given, the name quick-<loader>-<version> is used.

If --name matches an existing modpack, its mods are installed and its Minecraft version and loader are used.

Examples

Section titled “Examples”

Launch 1.21.1 vanilla in demo mode

Terminal window
cauldroncli start -v 1.21.1

Launch 1.20.1 Forge with an account and 6GB of RAM

Terminal window
cauldroncli start -v 1.20.1 -l forge -m <minecraft_access_token> -o ram=6,ram_low=2

Create a Fabric modpack from Modrinth and launch it

Terminal window
cauldroncli start -v 1.21.1 -l fabric -n my-pack --modrinth_mods fabric-api,sodium

Launch the same modpack again

Terminal window
cauldroncli start -n my-pack

Accounts

Section titled “Accounts”

--account takes a Minecraft access token. This is the access_token returned by Cauldron Authentication. The username and UUID are read from the token.

If no token is provided, the game launches in demo mode.

If the token cannot be read, the command exits with Invalid Token (no_account in headless mode).

Overrides

Section titled “Overrides”

Overrides are passed as comma separated key=value pairs.

Key Description
ram Maximum RAM (GB)
ram_low Minimum RAM (GB)
server_ip Join this server when the game starts
username Override the player name

Any other keys are ignored. To apply overrides to every launch, use custom_args.json.