Minecraft 26.4 Snapshot 1: Vulkan Takes Over and Servers Get Real Connection Controls

Mojang dropped the first snapshot for 26.4 this week, and while the patch notes read like a technical changelog at first glance, there's a lot buried in here that server owners should actually care about. The official post frames it as "a range of technical updates and improvements," which is Mojang-speak for "we rewired a bunch of stuff under the hood."

The headline change is that Vulkan is now the default graphics API. But the more interesting story, at least for anyone running a server, is a complete overhaul of how the game's connection handshake works. There's also a solid batch of bug fixes that kill off some genuinely old and annoying issues.

Vulkan Is No Longer Optional (Sort Of)

Mojang has been rolling out Vulkan support gradually for a while now, and this snapshot pushes it over the line. The "Default" graphics API setting now behaves identically to "Prefer Vulkan," meaning most players will get switched over without touching a single setting.

The game also stopped automatically reverting your graphics API after detecting a startup crash. That's a double-edged change. On one hand, it stops the game from silently flip-flopping your settings behind your back. On the other, if Vulkan is genuinely unstable on your hardware, you'll need to manually switch back to OpenGL yourself instead of the game doing it for you.

Worth noting: there's also a fix in this build for a Vulkan-specific rendering bug where pipelines always declared a D32_FLOAT depth attachment format, regardless of what was actually needed. Small fix, but it's the kind of thing that matters if you're troubleshooting graphics glitches on a shader pack or resource pack.

The Connection Protocol Just Got a Major Rework

This is the part of the patch notes that server admins should actually read twice. Mojang rebuilt how the client's intention packet works, and it's not a minor tweak.

Previously, the "host" field in the handshake just carried the domain name you typed into the server address box. Now it can carry a whole set of key-value parameters, formatted basically like a URL query string. Players can type things directly into the Server Address field in their multiplayer menu, and the game will parse them out automatically.

Any address in the form of id@host will be parsed as host?_id=id, giving server owners a built-in way to issue connection tokens without any plugin magic.

That's paired with a brand new allowed-connection-ids server property. If you set it, the server checks incoming connections against that list and rejects anyone who doesn't match before they even see the server in their multiplayer list. No ping response, no status, nothing. For anyone dealing with bot scanners hammering their server list entry or running invite-only communities, this is a genuinely useful tool that used to require third-party plugins or proxy-level hacks.

There's also a new status-contact-details property so server owners can embed a human-readable contact method in their server's status response, and an enable-legacy-status flag that lets you finally turn off support for the ancient pre-1.7 ping protocol if you don't need it.

Mojang Wants to Know What Mods You're Running

A new minecraft:mod_list custom packet payload shows up in this snapshot. The vanilla client sends an empty version of it since it has no idea what mods are installed, that part's still on Forge, Fabric, and NeoForge to fill in. But the groundwork is now officially part of the protocol instead of something modding platforms had to bolt on themselves.

For modded server admins, this should eventually mean better debugging when players report weird crashes or desyncs. Knowing exactly what client-side mods someone's running, without having to ask them in Discord, is a small thing that saves a lot of back-and-forth.

SRV Records and Bungee-Style Transfers Get Cleaner

If you run a BungeeCord or Velodyne network, or you rely on SRV DNS records to point players to a non-standard port, there's relevant news here too. The intention packet now carries both the original and resolved domain when SRV records are in play, fixing a long-standing inconsistency tracked as MC-278651.

The minecraft:transfer packet also picked up a new properties field, letting proxies pass custom key-value data along when shuffling a player from one server to another. Combined with the new host field format, this opens the door for proxy networks to build smarter routing logic without hacking around the protocol.

One caveat worth flagging: Mojang explicitly notes that since the intention packet is unencrypted, none of this should be used for anything security-sensitive. Treat the new properties as convenience data, not an auth system.

World Generation: A Few Quiet but Real Changes

Not everything in this snapshot is protocol plumbing. Upgrading old worlds that predate Caves and Cliffs will now generate sulfur caves retroactively below old terrain, closing a gap that's bugged legacy world owners for years. There's a new #is_cave biome tag too, which modpack and datapack authors will probably put to immediate use.

Mushroom placement rules changed as well. Red and brown mushrooms can now be placed on any solid-top block regardless of light level, matching how Bedrock Edition has always worked. They still won't spread without the right brightness, but builders no longer need to fake lighting conditions just to decorate with mushrooms.

Datapack creators should pay close attention to the cuboid placement modifier change. The xz_size and y_size fields now represent actual cuboid dimensions instead of being implicitly one block larger than stated. An xz_size of 2 used to produce a 3x3 area and now produces an actual 2x2. If you've got custom world gen features using this modifier, they will place differently after updating. That's not a bug, it's an intentional cleanup, but it'll catch people off guard if they don't read the notes.

Bug Fixes Worth Celebrating

Buried in the fix list are a handful of genuinely old annoyances finally getting squashed. The various involuntary-jump bugs when entities hit water near a wall (MC-8959, MC-44560, MC-50749) have been reported for over a decade across various Minecraft versions. Anyone who's ever built a water elevator and gotten launched sideways into a wall knows exactly what this fixes.

Item frames also got some real love this round. They now drop correctly when removed from ceilings instead of falling through the block they were attached to (MC-123848), and command-based rotation no longer causes desyncs between client and server (MC-299060). If you run a server with a lot of item frame-based displays or map walls, this one's for you.

There's a smaller but satisfying fix too: wolf armor now shows damage cracks on its dyed parts again, instead of hiding the wear-and-tear visually (MC-311859).

The full fix list runs much longer than what's covered here. Worth a skim if you run a technical server or a data pack-heavy modpack, since several of the fixes touch commands, NBT conversion, and world gen edge cases that only show up at scale.

What This Means Going Forward

None of this is flashy. There's no new mob, no new biome, no new building block to screenshot for a trailer. But the protocol changes here are the kind of infrastructure work that tends to pay off over several future updates, not just this one snapshot.

Server owners running public networks should look hard at the new allowed-connection-ids property. It's not a full replacement for anti-bot plugins, but it's a legitimate first line of defense baked directly into vanilla server software, and it costs nothing to set up.

As always, snapshots are for testing, not production servers. Back up your world before messing with any of this, especially if you're relying on custom world gen data packs that touch placed features or the cuboid modifier. Mojang will keep iterating on 26.4 over the coming weeks, so expect more snapshots to refine (or possibly revert) some of these networking changes before the stable release lands.