Project Overview

PulseNet is a Fabric mod that replaces Minecraft's default per-packet network flushing with a smart batching system. Outgoing packets are grouped and flushed together, drastically reducing kernel syscall overhead and event loop task scheduling while keeping combat, chat, and other latency-sensitive packets instant. Designed to work seamlessly alongside other Fabric mods via Mixin compatibility.

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Installation

PulseNet is a server-side Fabric mod. Drop it into your mods/ folder alongside Fabric API.

Requirements:

• Fabric Loader 0.18.5+

• Fabric API

• Minecraft 26.1+

• Java 25+

• Latest Builds: https://modrinth.com/mod/pulsenet

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Features

Feature	Description
Smart Packet Batching	Groups outgoing packets within a tick and flushes them in a single kernel syscall instead of one per packet. Supports three modes: smart_execution, strict_tick, and interval.
Write Queue	Replaces per-packet event loop task submissions with a single batched write task, eliminating lambda allocations and cross-thread scheduling overhead.
Packet Coalescing	Bundles similar low-priority packets (particles, sounds) into BundlePackets, reducing the client's received packet count.
Explosion Optimization	Detects mass block changes from explosions and replaces individual block update packets with a full chunk resend when a configurable threshold is exceeded.
Packet Classification	Automatically classifies packets as Critical, Instant, Chat, Ignored, or Coalesce — ensuring latency-sensitive packets (keepalive, disconnect, combat) always bypass the buffer. Fabric infrastructure packets (minecraft:register, minecraft:unregister) are handled at the Connection level to prevent mod handshake failures.
Real-Time Metrics	Built-in metrics system tracking logical/physical PPS, bandwidth, CPU usage, memory savings, and write queue efficiency. Viewable via commands or an in-game boss bar.
Mixin Compatibility	Uses a @WrapOperation approach that runs after all other mixins (Polymer, server-side translations, etc.), ensuring full compatibility with the Fabric mod ecosystem.
Hot-Reloadable Config	All settings are configurable via pulse.properties and in-game commands (/pulse config, /pulse reload) with no restart required.

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Commands

Command	Description
/pulse	Displays the current PulseNet version.
/pulse reload	Reloads the configuration from disk.
/pulse config	View and modify all configuration settings in-game.
/pulse netstats [network|cpu|ram|all]	Displays real-time network, CPU, and memory statistics.
/pulse netstats bar	Toggles the metrics boss bar overlay.
/pulse netstats reset	Resets all metrics counters to zero.
/pulse packetNames	Lists all observed packet class names and channel IDs.
/pulse packetNames classes	Lists only observed packet class names.
/pulse packetNames channels	Lists only observed custom payload channel IDs.
/pulse packetNames reset	Clears the observed packet name lists.

Config Commands

The following commands can be used to adjust configurable settings in the pulse.properties file without a server reboot (Use /pulse reload after running these commands to hotswap changes). These commands can be suffixed with a value to set the setting, or used without a value to view the current setting.

• /pulse config batchingEnabled Master toggle for the smart packet batching system. When true, outgoing packets are buffered and flushed in batches instead of individually. (default: true)
• /pulse config batchingMode Batching mode: smart_execution (flush on tick + limits), strict_tick (flush only on tick end), interval (flush on a timer). (default: smart_execution)
• /pulse config batchingMaxBatchSize Maximum number of packets to buffer before forcing a flush. (default: 1024)
• /pulse config batchingMaxBatchBytes Maximum bytes to buffer before forcing a flush. (default: 32000)
• /pulse config batchingFlushInterval Interval in milliseconds for the INTERVAL batching mode. (default: 25)
• /pulse config batchingSafetyMarginBytes Safety margin in bytes subtracted from the max batch bytes limit to prevent overflow. (default: 64)
• /pulse config batchingInstantPackets List of packet class names that should flush the buffer immediately when sent. (default: ClientboundHurtAnimationPacket, ClientboundDamageEventPacket, ClientboundBlockEntityDataPacket)
• /pulse config batchingIgnoredPackets List of packet class names that should always bypass the buffer entirely. (default: [])
• /pulse config batchingInstantChannels List of plugin channel IDs (e.g. axiom:hello) whose custom payload packets should flush the buffer immediately when sent. Use /pulse packetNames channels to discover channel IDs. (default: [])
• /pulse config batchingIgnoredChannels List of plugin channel IDs whose custom payload packets should always bypass the buffer entirely. Use /pulse packetNames channels to discover channel IDs. Note: minecraft:register and minecraft:unregister are handled at the Connection level and always bypass the buffer regardless of this list. (default: [])
• /pulse config batchingChatPacketsBypass When true, chat-related packets bypass the buffer for instant delivery. (default: true)
• /pulse config batchingOffThreadBypass When true, packets sent from off the server thread bypass the buffer. (default: true)
• /pulse config batchingWriteQueue When true, buffered packets are queued and written in a single event loop task instead of calling Connection.send() per packet, eliminating per-packet lambda allocations and cross-thread task scheduling. (default: true)
• /pulse config batchingPacketCoalescing When true, packets in the coalesce list are bundled together into BundlePackets on flush, reducing the client's received packet count. (default: true)
• /pulse config batchingCoalescePackets List of packet class names to coalesce into BundlePackets (e.g. particles, sounds). Supports inner classes with dot syntax (Foo.Bar). (default: ClientboundLevelParticlesPacket, ClientboundSoundPacket, ClientboundSoundEntityPacket)
• /pulse config batchingCoalesceBundleLimit Maximum number of sub-packets per BundlePacket. Vanilla client enforces a hard limit of 4096. (default: 4000)
• /pulse config optExplosionsEnabled When true, block updates from explosions are grouped by chunk and replaced with full chunk resends if they exceed the threshold. (default: true)
• /pulse config optExplosionsBlockChangeThreshold Number of block changes in a single chunk required to trigger a full chunk resend instead of individual updates. (default: 512)
• /pulse config optExplosionsLogOptimizations When true, logs a message each time the explosion optimization replaces block updates with a chunk resend. (default: false)
• /pulse config metricsEnabled When true, the metrics collection system is active and computes network statistics. (default: true)
• /pulse config metricsUpdateInterval How often (in seconds) the metrics system recomputes derived statistics. (default: 1)
• /pulse config metricsModuleNetwork Enables the network metrics module (PPS, bandwidth). (default: true)
• /pulse config metricsModuleCpu Enables the CPU metrics module (process CPU usage estimation). (default: true)
• /pulse config metricsModuleMemory Enables the memory metrics module (saved allocation estimation). (default: true)
• /pulse config metricsModuleWriteQueue Enables the write queue metrics module (event loop task savings tracking). (default: true)

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Permission Nodes

PulseNet uses the Fabric Permissions API for command permissions. Each node has a fallback vanilla permission level for servers without a permissions mod.

General

Node	Default	Description
pulsenet.pulse	ALL	Access the /pulse base command (shows version)
pulsenet.reload	GAMEMASTERS	Reload the PulseNet config file
pulsenet.netstats	GAMEMASTERS	View network, CPU, and memory statistics
pulsenet.netstats.bar	GAMEMASTERS	Toggle the metrics boss bar overlay
pulsenet.netstats.reset	GAMEMASTERS	Reset all metrics counters to zero
pulsenet.packetnames	GAMEMASTERS	List observed packet class names and channel IDs

Config

Config commands are generated dynamically per config value. The <name> below corresponds to the camelCase config key (e.g. batchingEnabled, metricsUpdateInterval).

Node	Default	Description
pulsenet.config	GAMEMASTERS	List all config values
pulsenet.config.<name>.get	GAMEMASTERS	Read a specific config value
pulsenet.config.<name>.set	GAMEMASTERS	Change a specific config value

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	Links in Chat	Makes URLs posted in chat clickable.

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Support and Contributions

PulseNet is an open-source project by PulseMC. We welcome contributions regarding Netty, Mixin, and protocol-level optimizations.

• Pulse Discord: Join our community
• Boris's Discord: Boris's Modding Discord
• Issues: Report bugs on GitHub

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