The Luau standard library

What the VM provides, on top of the engine's own API.

Scripts on Aero are Luau scripts. Besides game, Instance, and everything else in the API reference, the VM ships a standard library of its own. The Luau site, luau.org, documents each function.

Libraries

Library What it holds
string Text handling: lengths, casing, patterns, formatting.
table Arrays and dictionaries: insert, remove, sort, freeze.
math Constants and functions, including math.random.
os clock, date, difftime, and time.
coroutine Threads: create, resume, yield, status.
buffer Fixed-size binary buffers.
bit32 Bitwise operations on 32-bit integers.
utf8 UTF-8 encoding and decoding.

os is the narrowed one. Only the four functions above exist. There is no io, and no way for a script to reach files, processes, or environment variables.

vector builds Luau's native vector type. It is separate from the engine's Vector3: every property and method in the reference takes Vector3, and nothing in Aero hands a script a native vector.

debug is removed

Luau ships a debug library that reaches around the language: upvalues, hooks, tracebacks of other threads. The engine removes it before any script runs, so reading debug returns nil. Perf is the supported way to inspect what a script costs.

Base functions

The base globals are Luau's own: assert, error, pcall, xpcall, pairs, ipairs, next, select, unpack, tonumber, tostring, type, typeof, setmetatable, getmetatable, rawget, rawset, rawequal, rawlen, setfenv, and getfenv. Two older names ride along: gcinfo and newproxy.

_G is the globals table and _VERSION is the string Luau.

The run budget

A script that runs too long without yielding is stopped. A single uninterrupted run past five seconds raises Script exceeded its run budget. Yielding ends a run: task.wait, WaitForChild, and a signal's Wait hand control back, and the thread starts a fresh budget when it resumes.

See also