Hauteur

Let Bedrock Edition players explore and build above Y = 512 on custom-height Java worlds via dynamic Geyser vertical windowing.

Minecraft Java Edition datapacks can raise world height to Y = 2032 (used heavily by BuildTheEarth 1:1 alpine servers, mountain resorts, and megabuild projects), while Bedrock Edition clients hard-cap the Overworld at [-64, 320) ([-64, 512) with Geyser's extended height option). Above that ceiling, Bedrock players hit invisible air while Java players keep climbing.

Hauteur is a Geyser extension (dropped straight into Geyser's extensions/ folder—zero client mods or Bedrock add-ons required) that dynamically shifts a 16-block-aligned vertical window O per Bedrock player. Every Y coordinate sent to the Bedrock client is translated on the wire as Y - O, and every packet sent back is restored as Y + O, so a Java peak at Y = 1950 renders solidly in front of a Bedrock player.

How Hauteur Works Under the Hood

	Mechanism
	Per-Player 16-Aligned Height Window (Y ± O) Maintains an independent subchunk-aligned offset O per Bedrock session (window-step: 128, margin-top: 96, margin-bottom: 96). As a player climbs, descends, or teleports, Hauteur shifts O automatically and keeps an action-bar readout (Real Y: 1952 (window +1664)) visible whenever O ≠ 0.
	Live Chunk Cache & Subchunk Re-Slicing Caches full-height Java chunks (-2032 .. 2031) alongside single-block, section, explosion, and piston updates—then re-slices and streams only the subchunks overlapping the player's new Bedrock window upon rebasing, prioritized radially from the player outward.
	400 ms Rebase Freeze & Packet Replay Briefly holds entity-motion deltas during a window transition (freeze-millis: 400) and replays them seamlessly at the new offset once the center chunks arrive, preventing Bedrock clients from falling into unloaded air mid-shift.
	Absolute-Y Teleport Command Rewriting Leaves absolute commands (/tp x 1950 z) untouched while translating relative ~ Y coordinates from the Bedrock client's shifted frame back to real Java world coordinates (tp, tppos, teleport).

Diagnostic Commands

Aliases: /hauteur, /skywindow, /sw, /bho

Installation & Honest Scope

1. Run Java 21+ and Geyser (2.9.x+ / 2.11.2-SNAPSHOT on Standalone, Paper/Purpur/Folia, Fabric, Velocity, or BungeeCord).
2. Enable extended-world-height: true in Geyser's config.yml for the widest [-64, 512) (576-block) Bedrock window.
3. Place Hauteur-<version>.jar into Geyser's extensions/ folder (never plugins/ or mods/) and restart (migrates legacy SkyWindow/ configs automatically).

Links & Support

• Source Code, Full Config Reference & Issues: GitHub — MaxLananas/Hauteur
• Community & Support: Join our Discord

_{Licensed under MIT}