Minecraft Snapshot 26.3-10 Rewrites How Blocks Transform Into Other Blocks

Mojang dropped 26.3-snapshot-10 this week, and if you just skim the patch notes you might walk away thinking it's a quiet one. New main menu panorama, a few renamed items, a Realms splash screen. Cute, but not exactly headline material.

Except buried in the Data Pack Version 118 section is a system that datapack and plugin developers have wanted for ages: a real, moddable registry for block transformations. Axes stripping logs, hoes tilling dirt, shovels making paths, none of that has ever been something you could fully customize without digging into mixins or client-side hacks. That changes now.

Block Transformers: The Quiet Big Deal

Let's actually talk about this registry, because it's a bigger shift than the patch notes make it sound. Previously, when you right-clicked a block with an axe, hoe, or shovel, the behavior was hardcoded into the game's Java logic. Want a custom tool to strip a custom log variant? You were writing a mod, not a datapack.

Now every one of those interactions is defined through minecraft:block_transformer entries. Each entry specifies a block state provider for the output, an optional sound and particle effect, which faces can't be interacted with, loot tables for drops, and even how the transformation should ripple outward. There's a copper_chest transform type specifically so that waxing or scraping one half of a double chest also updates its other half.

"Contents have been moved to a separate registry. Component must now always refer to minecraft:block_transformer registry, existing inline components are removed."

That line about the minecraft:block_transformer component getting its contents pulled into a standalone registry is the real tell here. Mojang isn't just patching a feature, it's building infrastructure. Expect modpack and datapack creators to lean on this heavily once it's stable, for everything from custom tool progression systems to entirely new crafting-adjacent mechanics that don't involve a crafting table at all.

Worth noting: this is still a snapshot feature, so the format could shift before it lands in a full release. If you build something against it now, keep an eye on future snapshots for breaking changes.

A New Command for Doing Math Inline

The other technical addition worth your attention is /compute, alongside a matching compute source for /data modify. In plain terms, it lets you evaluate a number provider (think loot table math, but usable anywhere) in the context of a position, a block, or an entity, and spit the result into a command or data storage.

The example Mojang gives is pulling a scoreboard value off the nearest armor stand and writing it straight into storage:

/data modify storage foo bar set compute entity @n[type=minecraft:armor_stand] {type:score,target:{type:context,target:target_entity},score:baz}

If you've ever built a scoreboard-driven minigame or an RPG server with custom stat systems, this is the kind of tool that cuts out a dozen clunky command chains. It's not flashy, but command pack developers are going to get a lot of mileage out of it.

World Generation Keeps Getting Reorganized

Density functions have been in flux for a few cycles now, and this snapshot pushes that further. preliminary_surface_level is now chunk_surface_level and no longer gets implicitly interpolated across a whole chunk. Ore veins have been pulled out of the noise settings entirely and now live as their own minecraft:ore_vein material rule, with explicit fields for density, richness, and a filler gap override.

Mojang also merged a handful of overlapping cache functions, cache_2d, cache_all_in_cell, and flat_cache are gone, folded into a single renamed minecraft:cache. If you maintain a custom world generation datapack, this is the section to read carefully before updating, because several of your density function definitions will need adjusting.

Smaller Changes Worth Knowing About

• Drowned got their behavior and animation changes from this release cycle rolled back entirely. Something about the earlier tweaks wasn't landing right, and Mojang pulled the plug rather than iterate in public.
• Explorer maps are getting renamed across the board. Ocean Monument Explorer Map becomes Ocean Monument Map, Trial Chambers Explorer Map becomes Buried Trial Chambers Map, and so on. Cosmetic on the surface, but the associated structure tags changed too (#on_trial_explorer_map is now #on_buried_trial_chambers_map), so any datapack referencing the old tag names needs an update.
• Structure locating got a performance improvement. No specifics on numbers, but if your server runs plugins or command blocks that search for structures frequently, this should help.
• Eating Chorus Fruit now shows directional particles pointing toward where you're about to teleport, and there's a new directional_particles boolean in the teleport_randomly consumable effect if you want to turn that off for custom items.
• The none swing animation type is back, affecting the /swing command and the attack and interact animation components.

What This Means If You Run a Server

None of this is going to change how your server plays tomorrow. Snapshots are for testing, not production, and 26.3-10 is squarely aimed at developers rather than end users. But the direction is clear: Mojang keeps pulling hardcoded game logic out into data-driven registries that datapacks and resource packs can touch. Block transformers are the latest and arguably most significant example.

If you maintain custom content, whether that's a survival server with custom crafting mechanics or a full-blown modpack-adjacent datapack, this is the kind of groundwork that pays off a few updates down the line. The structure tag renames are the one thing that could bite you immediately if you're not paying attention, since anything referencing the old explorer map tag names will silently break.

Mojang's own framing says it best: these are "a variety of technical changes and improvements" worth digging into, even if the headline feature is a cozier main menu.

For the full rundown, including every data component tweak and tag addition, check the official patch notes on Minecraft.net.