26.1 Snapshot 1 (known as 26.1-snapshot-1 in the launcher) is the first snapshot for Java Edition 26.1, released on December 16, 2025. It adds data pack-controlled trading, improves the game's lighting and the look of the Night Vision effect, and makes other technical changes (i.e. related to data packs). Full changelog: https://minecraft.wiki/Java_Edition_26.1-snapshot-1