How to Run Mixed Forge/Fabric Server (Sinytra Connector)
Guide to setting up a Sinytra Connector server that runs Fabric mods on Forge, covering installation, compatibility layers, and troubleshooting mixed mod setups.
What Is Sinytra Connector?
Sinytra Connector is a compatibility layer that allows Fabric mods to run on Forge (and NeoForge) servers. This is significant because the Minecraft modding community is split between two ecosystems, and many popular mods exist only on one loader. Sinytra Connector bridges that gap, letting you combine Forge and Fabric mods in a single server instance. If you need a sinytra connector server setup, this guide walks through every step.
The project is still in active development, so not every Fabric mod works perfectly. Mods that rely heavily on Fabric API internals or use aggressive Mixins may have issues. However, many popular Fabric mods (Sodium alternatives, optimization mods, simple content mods) work well through the connector.
Requirements for Sinytra Connector Server Setup
You need a working Forge or NeoForge server as your base. Sinytra Connector is a Forge-side mod, so it installs into your existing Forge mods folder. You also need:
- Forgified Fabric API. This is a re-implementation of the Fabric API that runs on Forge. Download it from the Sinytra Connector GitHub or CurseForge page. Place it in your
mods/folder alongside the connector. - Sinytra Connector mod jar. Download the version matching your Minecraft and Forge/NeoForge version.
- Fabric mods you want to add. Download them as you normally would from Modrinth or CurseForge, just the regular Fabric versions.
The sinytra connector server setup requires Java 17 for 1.20.1 or Java 21 for 1.21+. Match the Java version to your Minecraft version, not to any specific loader requirement.
Installation Steps
- Stop your Forge/NeoForge server.
- Place the Sinytra Connector jar and Forgified Fabric API jar in
mods/. - Place the Fabric mods you want to use in the same
mods/folder, alongside your existing Forge mods. - Start the server and watch the console for errors.
On first boot, the connector processes Fabric mods and wraps them for Forge compatibility. This adds extra startup time, typically 30 to 60 seconds depending on how many Fabric mods you added. Subsequent boots are faster because the connector caches its transformations.
Compatibility and Troubleshooting
If a Fabric mod fails to load through the sinytra connector server setup, the console will show a clear error message naming the mod and the reason. Common issues include:
- Mixin conflicts between a Fabric mod and a Forge mod targeting the same vanilla class. Remove one of the conflicting mods.
- Unsupported Fabric API modules. Some niche Fabric API features are not yet implemented in the Forgified version.
- Version mismatches between the connector, the Forgified Fabric API, and your Forge version. Always use matching release versions.
Check the Sinytra Connector GitHub issues page for known incompatibilities before reporting bugs. The project maintains a compatibility list of tested mods.
Performance Considerations
Running the connector adds a small overhead to mod loading and startup, but runtime performance is comparable to running mods natively on their intended loader. Allocate RAM based on your total mod count as you normally would. For sizing guidance, see our RAM calculator and JVM flags guide.
If you are deciding between a mixed setup and converting your pack entirely, our Forge-to-Fabric conversion guide explains the trade-offs of switching loaders completely.
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