Custom Player Data
by Hdi
Custom Player Data lets a server or another mod attach custom variables to each player, saved in the player.dat file and synchronized to clients.
What it does
Variables defined through a JSON schema are attached to each player, written to the native player.dat file and kept in sync between server and client. Once a connection is made, the variables are sent to the client, so a HUD can display them without extra setup. The schema file is generated automatically in the map folder when the mod first runs.
The mod is built for Minecraft servers and for developers who manage persistent player data. A developer API lets other mods read and change the variables from code through PlayerDataStore, and admin commands let operators get and set values in game. Complex data types are supported through ICustomDataType, and runtime checks enforce minimum and maximum values, missing-value handling and type verification. Dependent mods declare the dependency in their fabric.mod.json file and call the mod's onInitialize method.
Custom Player Data is published for Fabric and Quilt for 1.20.6 only. It runs on the client and server, so both sides need it. The mod is released under All rights reserved and is not open source. Six catalog mods already require it, including Star Wars Original Trilogy, The Flash CW Season 1 Core, Essentials Utils Commands, Player Statistics Utils and Down But Not Out.
Key features
JSON schema variables
Player variables are defined in a schema file that is generated automatically in the map folder.
Automatic synchronization
Values are stored in player.dat and pushed to clients on connection, so HUDs can show current data.
Developer API
PlayerDataStore gives other mods access to the variables from any server code, for reading and writing.
Custom data types
Complex types such as skill or quest records can be built by implementing ICustomDataType.
Admin commands
Operators can get and set player data in game, with minimum and maximum, missing-value and type checks applied at runtime.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Required by 6 mods
Use cases
Server progression data
A server can store skill levels or quest progress per player and keep them across sessions.
Custom HUDs
Synchronized variables let a client-side interface show values that the server controls.
Who it’s for: Server owners who need persistent per-player values and mod developers who want to store or share those values with other mods.
Questions
Does Custom Player Data need to be installed on both sides?
Which loaders does Custom Player Data support?
Where does the mod keep each player's values?
In the catalog
Custom Player Data is one of 4,058 Storage mods on ModsFinder, and one of 2,474 Storage mods for Fabric. 11,154 mods support Minecraft 1.20.6.
More from Hdi
Similar mods
What the author says
Fabric Framework 1.20.6 for managing persistent and synchronized player data. This mod allows you to define custom variables attached to each player, which are saved in Minecraft's native player.dat file and automatically synchronized between the server and the client.
Official listing
- Modrinth page
- modrinth.com/mod/custom-player-data
- Owner
- Hdi
- Published
- 2026-03-15
- Updated on Modrinth
- 2026-10-06
- Facts verified
- 2026-10-15