Minecraft Java 26.1 Snapshot 1 Patch Notes: Trade Overhaul, New Lighting System

Minecraft Java Edition kicks off 2026 with 26.1 Snapshot 1, released on December 16, 2025. This snapshot introduces the new calendar-year-based versioning system, where major releases start with the year followed by drop and patch numbers. It also marks several foundational technical upgrades, including a shift to Java 25 and fully unobfuscated builds for easier modding and development.

Java 25 Requirement and Unobfuscated Builds

The snapshot requires Java 25, upgrading from Java 21. The bundled runtime is now the Microsoft build of OpenJDK 25, bringing performance improvements like compact object headers for reduced memory usage (enable with -XX:+UseCompactObjectHeaders). All future builds, including this one, are fully unobfuscated, simplifying access to game code for modders and server operators.

Server operators get a new toast notification for low disk space, helping prevent crashes.

Data-Driven Villager Trades

Villager and Wandering Trader offers are now fully data-driven, controlled via data packs in the villager_trade and trade_set folders. Trades use deterministic random sequences like loot tables, ensuring consistent generation based on seeds.

Key features:

Trade blueprints define inputs (wants), outputs (gives), max uses, XP rewards, reputation discounts, and predicates (e.g., profession-specific).
Item modifiers add randomness, like random enchantments or potions, with support for doubling costs on high-value enchants (via #minecraft:double_trade_price).
Trade sets group trades by profession/level (e.g., #armorer/level_1), allowing configurable amounts and duplicates.

This enables custom economies, balanced trading halls, and seed-based perfect trades. Data pack version bumps to 95.

Revamped Lighting System

The lightmap algorithm is rewritten for simplicity and fixes:

Consistent Darkness and Wither darkening across all dimensions.
Night Vision adds ambient light without over-brightening dark areas.
Data-driven tints via new environment attributes: block_light_tint (default yellowish for torches), ambient_light_color (dimension-specific), and night_vision_color.

A lightmap debug renderer (F3 + 4) shows real-time block/sky light previews in the corner.

New /swing Command

/swing <mainhand|offhand> animates arm swings on supported entities (e.g., Mannequins), expanding animation options for maps and NPCs. It returns the number of affected entities.