Lync

Buffer networking for Roblox.

Releases · Install · Example · API · Codecs · Benchmarks

Schemas, packets, queries, groups, validation, rate limiting. Every send batches into one buffer per player per frame; identical frames XOR to ones already in flight; delta codecs collapse unchanged state to a single byte. No code generation.

Install

Wally — add to your wally.toml:

Lync = "axp3cter/lync@2.3.3"

npm (roblox-ts):

npm install @axpecter/lync

import Lync from "@axpecter/lync";

Important. Define every packet, query, and group before Lync.start(). Definitions assign sequential 7-bit IDs that both peers must agree on; defining late on one side desyncs the wire.

Example

Shared — ReplicatedStorage.Net

local Lync = require(game.ReplicatedStorage.Lync)

return table.freeze({
    State = Lync.packet("State", Lync.deltaStruct({
        position = Lync.vec3,
        health   = Lync.float(0, 100, 0.5),
        status   = Lync.enum("idle", "moving", "attacking", "dead"),
        alive    = Lync.bool,
    })),

    Hit = Lync.packet("Hit", Lync.struct({
        targetId = Lync.int(0, 65535),
        damage   = Lync.float(0, 200, 0.1),
    }), {
        rateLimit = { maxPerSecond = 30, burst = 5 },
        validate  = function(data) return data.damage <= 200, "damage" end,
    }),

    Ping = Lync.query("Ping", Lync.nothing, Lync.f64, { timeout = 3 }),
})

Server

local Lync    = require(game.ReplicatedStorage.Lync)
local Net     = require(game.ReplicatedStorage.Net)
local Players = game:GetService("Players")

local alive = Lync.group("alive")
Players.PlayerAdded:Connect(function(p) alive:add(p) end)

Net.Hit:on(function(data, sender) end)
Net.Ping:handle(function() return os.clock() end)

Lync.start()

game:GetService("RunService").Heartbeat:Connect(function()
    Net.State:send(getState(), alive)
end)

Client

local Lync = require(game.ReplicatedStorage.Lync)
local Net  = require(game.ReplicatedStorage.Net)

Lync.start()

local scope = Lync.scope()
scope:on(Net.State, function(state) end)

Net.Hit:send({ targetId = 123, damage = 45 })
local serverTime = Net.Ping:request(nil)

API

Lifecycle

Configure options

Packets

Lync.packet(name, codec, options?)

-- Server
packet:send(data, player)
packet:send(data, Lync.all)
packet:send(data, Lync.except(p1, group1))
packet:send(data, { p1, p2, p3 })
packet:send(data, group)

-- Client
packet:send(data)

-- Both sides
local conn = packet:on(function(data, sender, timestamp) end)
packet:once(fn)
local data, sender, timestamp = packet:wait()
packet:name()
packet:stats() -- requires stats=true

Queries

Lync.query(name, requestCodec, responseCodec, options?)

Request-response on top of two paired registrations. Single-target requests yield until reply or timeout; multi-target requests gather a partial map.

-- Server
query:handle(function(data, player) return response end)
local resp = query:request(data, player)        -- response?
local map  = query:request(data, group)         -- { [Player]: response? }

-- Client
query:handle(function(data) return response end)
local resp = query:request(data)                -- yields; nil on timeout

Groups

Lync.group(name) — named player set. Members auto-removed on PlayerRemoving. Iterable: for player in group do.

Scope

Lync.scope() — batches connections for a single :destroy().

local scope = Lync.scope()
scope:on(packet, fn)
scope:once(packet, fn)
scope:add(rbxConnection)
scope:destroy()

Targets

Server-side :send second arg.

Middleware

-- Return Lync.DROP from onSend to discard a packet.
Lync.onSend(function(data, name, player) return data end)
Lync.onReceive(function(data, name, player) return data end)
Lync.onDrop(function(player, reason, name, data) end)

All return a Connection. A throwing hook surfaces to the caller and aborts the chain at that point.

Connection

Stats

Enable with Lync.configure({ stats = true }).

Debug

capture / stop / dump are reserved no-ops for capture/replay tooling.

Codecs

Numbers

Strings & buffers

Roblox types

Quantized variants

Call as a function for compression.

Composites

Delta — reliable transport only

Tracks the previous frame's value and ships only what changed. Rejected on unreliable = true.

• deltaArray element / deltaMap key+value cannot themselves contain delta state. Use deltaStruct for per-field deltas inside.
• deltaVec3 and deltaCFrame error on out-of-range components.

Meta

Rate limiting

Per-packet, pick one mode:

• Token bucket: { maxPerSecond = N, burst = M }
• Cooldown: { cooldown = seconds }

Global per-player cap: Lync.configure({ globalRateLimit = { maxPerSecond = N } }).

Limits

Benchmarks

rojo serve bench.project.json with one server + one client.

Cross-library — 1000 fires/frame, 10 s

Blink's methodology: same payload reused every frame, identical entity / bool shapes. Other tools from Blink v0.17.1.

Network bandwidth — 100 fires/frame, 8 s

License

MIT