WhereWasI

The client-side mod records a playthrough automatically while the game runs. It logs sessions, where time is spent, first-time item pickups, large hauls, deaths, dimension changes and advancements, scoring each entry by importance so that a first diamond ranks above the hundredth stack of cobblestone. When a world is loaded again after some time away, a resume briefing summarizes the recent journal, so no one has to remember where they left off.

The journal is built from numbers the game already keeps. Rather than tracking counts itself, the mod sends the request the vanilla Statistics screen already sends and reads the answer, so blocks mined, mobs killed and distance travelled match the figures the server keeps. Because it only reads existing data, it changes nothing about blocks, items, recipes or commands, and servers cannot tell it is installed. Entries stay on the player's own disk as plain JSON that can be removed at any time.

WhereWasI is for NeoForge 1.21.1 only and is licensed under All rights reserved, so it is not open source. Its public source code is available, while the mod itself is distributed under those terms. It is installed on the player's side alone, so servers need nothing.