Getting started¶

How to install Lync, declare a schema, and wire the server and client.

Install¶

WallynpmModel

[dependencies]
Lync = "axp3cter/lync@4.0.3"

npm install @axpecter/lync

Then see roblox-ts for the tsconfig.json change.

Take Lync.rbxm from the latest release and place it in ReplicatedStorage.

Declare a namespace¶

Every definition lives in a namespace. Declare it with define, in a module the server and every client require.

ReplicatedStorage/Net.luau

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

return Lync.define("lobby", {
    Ping = Lync.packet(Lync.empty()),
    Notice = Lync.packet(Lync.str(1, 200)),
})

The name is how the two sides find each other. Each namespace gets its own remotes.
define returns the same table, frozen.
When a client joins, its schema is compared with the server's. A client whose schema differs is refused with an error.

A game can have one namespace or several. Separate namespaces can be flushed on their own schedules.

Wire both sides¶

Each side attaches its listeners, calls start once, and calls flush every frame.

ServerScriptService/Net.server.luau

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

Net.Ping:onServer(function(_, player)
    Net.Notice:fireClient(player, "pong")
end)

Lync.start()
RunService.PostSimulation:Connect(function()
    Lync.flush()
end)
game:BindToClose(Lync.close)

StarterPlayerScripts/Net.client.luau

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

Net.Notice:onClient(function(text)
    print(text)
end)

Lync.start()
RunService.PostSimulation:Connect(function()
    Lync.flush()
end)

Net.Ping:fireServer()

The order of things¶

Rule	Why
Require every module that calls `define` before `start`.	`start` opens the namespaces that exist. A `define` after it throws.
Register query responders before `start`.	`start` seals them. Packet and set listeners can attach at any time.
Send after `start`.	Fires, requests, set writes and audiences throw before it.
Flush every frame, from your own function.	Nothing is sent until a flush. A signal connected to `flush` directly passes the frame time, which `flush` reads as a byte budget and refuses.
Bind `close` on the server only.	`BindToClose` is a server API. A client needs no shutdown call.

Lifecycle covers start, flush and close in full. The rest of the guide assumes both sides are wired as above, and marks the lines that must run after start.