Hero Studios

HeroSync Docs

~2 min read vr1.4.0 Fabric

Overview #

HeroSync is a client-side latency-compensation framework. It does not reduce your ping — it reduces what your ping feels like. Actions register instantly on your side (zero perceived delay), then outbound and inbound packets are observed and reconciled against authoritative server truth. When the server disagrees, a dedicated rollback engine reverses only what needs reversing, backed by state snapshots for consistent rollback points — all without a server mod and inside a sub-2ms per-client-tick budget.

Network latency makes otherwise-fine gameplay feel heavy. HeroSync removes that feeling client-side: your actions register instantly, then reconcile with the authoritative server — rolling back cleanly when the server disagrees.

Quick start #

  1. Download the HeroSync JAR for your exact Minecraft version (1.21 → 1.21.11 published; 26.x experimental).
  2. Place it in your Fabric mods folder (Fabric API recommended) — nothing to install server-side, ever.
  3. Join any server — actions now feel responsive immediately; the reconciliation engine works silently in the background.
  4. Open the in-game settings screen to tune or disable individual features, or edit config/herosync.json (created after first launch).
  5. Press F3+L to toggle the debug overlay and confirm the framework is active on your current server.
  6. Use /herosync status and /herosync stats to inspect current state, transactions and per-tick cost.
  7. Run /herosync reload after editing config/herosync.json to apply changes without restarting.
  8. Keep the JAR matched to your Minecraft version for best results — 26.x builds are bundled-mappings and experimental.

Configuration #

HeroSync tunes through config/herosync.json — optional, created after first launch or via /herosync reload. Individual features and the whole framework can be disabled from this file. JSON5 tolerates comments and trailing commas.

SettingDefaultDescription
Feature togglesAll enabledIndividual latency-compensation features (instant registration, reconciliation, rollback) can be disabled one at a time.
Framework master toggleEnabledDisables the whole HeroSync framework in one switch.
Debug overlayOff (F3+L)Live latency-compensation diagnostics — toggled in-game with F3+L or /herosync debug overlay.
Performance budgetSub-2ms per client tickThe engine is designed to stay inside this budget even when fully enabled.

Frequently asked questions #

Does this work on servers without the mod?
Yes. HeroSync is client-side and requires nothing on the server.
Will it get me banned?
It compensates for latency like predictive clients do — it never fabricates confirmations. Always check server rules first; some communities restrict predictive behaviour even when it is client-side.
Which versions are supported?
1.21 through 1.21.11 plus experimental 26.x builds (26.1 → 26.2). Keep the build matched to your Minecraft version.
Does it change my actual ping?
No — it changes how lag feels by making your inputs register locally (0ms perceived delay), then reconciling with the server.
Can I turn it off?
Yes — individual features and the whole framework can be disabled from config/herosync.json, or tuned from the in-game settings screen.
How much does it affect performance?
It keeps a sub-2ms per-client-tick performance budget, even with everything enabled.
Is there a command interface?
Yes — /herosync exposes status, transaction lists, registration toggles, stats, a debug overlay (F3+L) and reload. Run /herosync status to see current state, /herosync transaction list to inspect recent transactions, and /herosync stats for per-tick cost and reconciliation counters.
Can other mods integrate with it?
Yes — it ships a developer API (HeroSyncAPI) with registration rules, packet classifiers, snapshot providers and compatibility adapters.
What happens when the server disagrees with me?
The rollback engine reverses only what needs reversing — backed by state snapshots for consistent rollback points — instead of rubber-banding your whole position.

Compatibility #

PropertyValue
Loader / platformFabric
Minecraft versions1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4, 1.21.5, 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10, 1.21.11, 26.1, 26.1.1, 26.1.2, 26.2
Latest versionr1.4.0

26.x builds are experimental (bundled-mappings).

Learn more. Step-by-step walkthroughs live in the tutorials, with install guides for every platform and a general guide to configuration. Still stuck? Open the support portal and we'll reply from support@herostudios.dev.
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