A comprehensive networking and server-authority mod for Valheim dedicated servers. Combines compression, send-rate tuning, queue management, server-side simulation, RPC filtering, and a per-client auto-tuner into a single drop-in plugin.
Valheim's vanilla networking is built around small, friend-group sessions. It works fine for 4 people and starts visibly straining around 8+. This mod replaces the bottlenecks:
You don't need to be a networking engineer to run a heavily-modded server with this. That's the point... I'd rather you not touch your configs at all if you dont understand what they do.
The mod now ships with an auto-tuner that handles config adjustments. Most users should never need to touch a config setting again. (only settings that a client should ever touch will be player sync settings per prefernce)
When a client connects to a server for the first time, the mod runs a brief network/hardware probe:
The result is one of three tiers — LOW, MED, or HIGH — combining hardware capability and link quality. The tier is cached per-server for 7 days; reconnecting picks up where you left off.
After the initial probe, the mod periodically re-probes latency every 5 minutes. Each result goes into a rolling buffer. This catches:
The cache is updated whenever consensus changes, so the next reconnect starts with the corrected tier.
When the mod runs on a dedicated server with Enable Server Auto-Tune = true (the default), the server scores its own CPU/RAM at startup and applies a server-tier preset to:
The send-rate Min stays at a safe baseline regardless of server tier so Steam can always back off
The server also collects tier reports from connected clients and periodically logs the median client tier with suggestions, so an admin can see at a glance whether the server's settings actually match the audience joining.
These run on the dedicated server (the mod auto-detects). Effects are visible to all connected clients regardless of whether they have the mod installed.
| Feature | What it does |
|---|---|
| ZSTD compression | Compresses outbound traffic with a tuned dictionary. Significant bandwidth saving on busy servers, especially with large modded worlds. |
| Higher Steam send rates | Vanilla caps at ~150 KB/s; we open Min/Max up to 1024 KB/s. Less waiting during big fights or zone bursts. |
| Larger send queue | Default 80KB instead of vanilla ~10KB. Fewer dropped updates under burst load. |
| Steam SendBufferSize tuning | Per-connection outbound buffer up to 2MB. Directly addresses errors during initial-sync floods with heavy modpacks. |
| ZDO delta compression | On resyncs, only the fields that changed are sent — not the whole ZDO. Big savings on creatures/players where 1-2 fields change per tick. |
| Distance-based ZDO throttling | Distant objects (creatures/structures beyond ~500m) update at a lower rate. Combat-range objects stay full speed. |
| AI LOD throttling | Distant AI runs FixedUpdate at half speed. Server CPU saving with possible visible effect for nearby players depending on throttle distance. |
| WearNTear server optimization | Skips structural support recalculation for full-health/Inf health or fully intact pieces. Big CPU win on servers with large built bases. |
Vanilla Valheim relies on whichever client is "near" an object to simulate it. This mod makes the server authoritative instead:
Server authority is server-only behavior. Clients receive the results but don't run the simulation themselves.
If you're a player joining someone else's server, your config has dozens of settings...
but the ONLY section relevant to you is Player Sync.
Everything else is either server-driven or auto-tuned.
If you believe you know best, feel free to adjust, but adjusting settings incorrectly
can easily make the mod have the opposite effect from intended...
The Player Sync section has four options:
Enable Client-Side Interpolation (default: off) Smooths other players' movement on your screen by interpolating between received network positions, eliminating the small snapping that comes from discrete network ticks. Most players don't need this — the rest of the mod's improvements deliver positions smoothly enough on their own, and interpolation adds a small render-lag. Turn ON if you still see other players snap/teleport on a healthy connection.
Enable Client-Side Prediction (default: off) Extrapolates other players forward using their last known velocity. Helps on high-latency (>100ms) connections where interpolation alone can't cover the gap. Auto-tune may flip this on automatically if your measured ping warrants it. Leave it off otherwise — it can overshoot at low ping.
Smoothing Min Interval (default: 0.0s) Below this inter-packet arrival rate, smoothing is disabled and vanilla movement renders directly. 0 means "always smooth"; raise it only on LAN/very low-latency servers if you want fast packets to bypass smoothing.
Smoothing Max Interval (default: 0.20s) Above this inter-packet arrival rate, smoothing runs at full strength. Between Min and Max the strength fades in linearly. Raise for a more aggressive fade (less smoothing on borderline connections); lower for a snappier ramp to full smoothing.
Everything else in the config is either server-only or auto-tuned.
The mod automatically disables server-only features on clients regardless of what you set.
so that you can't manually toggle Enable Server-Side Simulation on your client,
but im not smart enough to know how to hide the config to only clients while allowing admins and servers to see it.
VAGhettoNetworking.dll into BepInEx/plugins/ on every machine that should have it.Built on the shoulders of BetterNetworking and Serverside Simulations. The general approach to ZDO throttling, RPC routing/AoI filtering, and ZSTD wire compression took inspiration from those mods and from the Comfy Valheim BetterZeeRouter pattern. The auto-tuner, rolling monitor, server self-tune, and Steam send-buffer tuning are original to this mod as far as I know... but theres only so many different ways to do networking mods in valheim
License: see LICENSE in the repo.