Supported Versions

NeonFX uses separate builds for different Minecraft version families.

Always install the JAR that matches the Minecraft version used by your Paper server.

Minecraft 1.21.x

Use the NeonFX build compiled for:

mc.1.21.4

This build uses the paper-1.21 adapter and requires:

• Paper 1.21.x
• Java 21

It is compiled against the Paper 1.21.4 API and is intended for supported 1.21.x releases where the required API remains compatible.

Minecraft 26.1

Use the build containing:

mc.26.1

This build uses the paper-26 adapter and requires Java 25.

Minecraft 26.2

Use the build containing:

mc.26.2

This build also uses the paper-26 adapter and requires Java 25.

Minecraft 26.3

Use the build containing:

mc.26.3

This build uses the paper-26 adapter and requires Java 25.

The current 26.3 build targets the Paper 26.3 beta API and should be retested when Paper publishes a stable API for that version.

Using the wrong build

Do not copy a NeonFX JAR between Minecraft version families unless that build is specifically intended for that version.

Each build contains version-specific compatibility handling and resource-pack metadata.

If NeonFX detects an unknown server version, it logs an adapter warning.

Resource Pack Compatibility

The NeonFX resource pack is also target-specific.

Use the resource pack generated by the same NeonFX build installed on the server.

NeonFX validates the pack metadata at startup and can regenerate its local pack when the detected Minecraft format does not match.