Minecraft Java Edition 1.21.9 introduces several features aimed at enhancing server management and gameplay experience. This update was published on 2025-09-30 19:04:00.
Minecraft Server Management Protocol
A server management API has been added for dedicated servers. This API is disabled by default and can be activated in server.properties by setting management-server-enabled=true. The API allows for querying and updating server states, including players and game rules. Notifications on state changes, such as player joins, are also supported.
Clients must authenticate to access the API by supplying an Authorization bearer token header with a server-specific secret. The secret must be exactly 40 alphanumeric characters. If left empty, it will be automatically generated. Unauthorized requests will receive a 401 Unauthorized response. TLS is enabled by default, requiring a keystore file specified in server.properties.
Chat Drafts and Code of Conduct
Unsent chat messages will now be saved as Chat Drafts if the chat is forcibly closed. Players can restore draft text by interacting with it. An option has been added to the Chat Settings screen to enable saving unsent messages by default. Additionally, a Code of Conduct screen can be shown when connecting to a server, and accepting it is required to play.
Server properties now include a boolean field called enable-code-of-conduct. Setting this to true will prompt the server to look for Code of Conduct files in a designated subfolder. Each file must be in UTF-8 format.
Performance Improvements and Changes
Several performance improvements have been made, including better entity rendering order and the removal of fixed “Spawn Chunks.” The world loading screen now shows chunks the player is about to enter. Additionally, the game requires OpenGL 3.3 to play, which does not change the posted Minimum Requirements.
Multiple server properties have been migrated into game rules, allowing for real-time changes. New game rules include pvp and spawnMonsters. The logic for mob spawning has also been tweaked to include Copper as a possible equipment type.
