Player history

Why UUIDs

Player history is stored by UUID, not by username. That keeps first-time status stable when a player changes their name.

Storage location

History is stored per world at:

<world>/dynamic-join-greetings/players.json

Example schema:

{
  "schemaVersion": 1,
  "players": [
    "11111111-2222-3333-4444-555555555555"
  ]
}

First install on an existing server

When the history file does not exist yet, the mod scans:

<world>/playerdata

Every valid *.dat UUID is imported as a known player. Those players receive returning greetings, which prevents established community members from getting first-time greetings after the mod is installed.

How first-time status is determined

1. On join, the mod attempts to add the player UUID to history.
2. If the UUID was new, the join is treated as first-time and the history file is saved.
3. If the UUID was already present, the join is treated as returning.

Simulation and preview do not write to this history.

Damaged history recovery

If players.json is malformed or uses an unsupported schemaVersion:

1. The damaged file is renamed to a timestamped .corrupt-<timestamp>.bak file.
2. History is rebuilt from Minecraft’s existing playerdata.
3. The server continues starting normally.

If the history directory cannot be written, the mod falls back to temporary in-memory history for that session and logs an error.

Reset a single player

There is no reset command. Stop the server first, then edit the JSON manually:

1. Stop the server.
2. Open <world>/dynamic-join-greetings/players.json.
3. Remove the target UUID from the players array.
4. Save the file with valid JSON.
5. Start the server.
6. Have that player join once. They should receive a first-time greeting and be re-added to history.

Reset all player history

To treat every next join as first-time:

1. Stop the server.
2. Replace players.json with an empty list:

{
  "schemaVersion": 1,
  "players": []
}

3. Start the server.

Editing rules

Do not edit players.json while the server is running. The mod may overwrite your changes on the next save.