Deeplink API

Deeplinks can be used to automatically launch or bring SJMCL to the foreground and perform certain actions. They are suitable for external integrations such as web pages, toolchains, and desktop shortcuts.

The protocol scheme is always sjmcl://.

NOTE

On Windows and Linux portable builds, this feature is available only after the launcher has been run at least once. On macOS, it is available only in the DMG build.

add-auth-server

Opens the Add Authentication Server dialog and automatically fills in the target third-party authentication server address.

NOTE

This interface does not directly save a new third-party authentication server. The user still needs to confirm the action in the launcher.

Format

sjmcl://add-auth-server?url=<server_url>

Parameters

Parameter	Type	Required	Description
url	string	Yes	Authentication server URL. Passing the root URL of an authlib-injector / Yggdrasil service is recommended

Examples

sjmcl://add-auth-server?url=https%3A%2F%2Flittleskin.cn%2Fapi%2Fyggdrasil
sjmcl://add-auth-server?url=https%3A%2F%2Fexample.com%2Fapi%2Fyggdrasil

launch

Launches an instance and directly enters the launch flow. SJMCL itself also uses this endpoint to generate desktop shortcuts for launching instances.

Format

sjmcl://launch?[id=<instance_id>][&playerId=<player_id>][&quickPlaySingleplayer=<world_name>][&quickPlayMultiplayer=<server_addr>]

Parameters

Parameter	Type	Required	Description
id	string	No	Instance ID. If omitted, the launcher uses the currently selected instance
playerId	string	No	Player ID. If omitted, the launcher uses the currently selected player
quickPlaySingleplayer	string	No	Automatically enter the specified singleplayer world
quickPlayMultiplayer	string	No	Automatically join the specified multiplayer server address

Parameter Notes

• When id and playerId are set to tbd, a selection dialog appears during the launch flow so the user can choose the instance or player manually
• In some specific cases, if no instance or player is currently selected, the selection dialog may also appear even without passing tbd
• Query parameter order does not matter. It is recommended to URL-encode each parameter value individually, especially when it contains spaces, colons, or other special characters

Examples

sjmcl://launch?id=OFFICIAL_DIR%3A1.20.1
sjmcl://launch?id=CURRENT_DIR%3AFabric%201.20.1&playerId=e9755ca2-6ebf-4ea7-a548-cf1074ab7f0f
sjmcl://launch?id=OFFICIAL_DIR%3A1.20.1&quickPlaySingleplayer=My%20World
sjmcl://launch?id=OFFICIAL_DIR%3A1.20.1&quickPlayMultiplayer=mc.example.com%3A25565
sjmcl://launch?id=tbd&playerId=tbd