debug.getstack Synchronous

getstack

Read the register values of a visible Luau stack frame. It helps diagnose an active call when you need its current values, not just the function’s compiled metadata.

Syntax

Luau

debug.getstack(level: number, index: number?) -> any OR {[number]: any}

Parameters

Function parameters
Parameter	Type	Description
`level`	`number`	Visible stack level; level 1 is the immediate caller.
`index`	`number?`	Optional one-based register slot. Omit it for all slots.

Returns

any OR {[number]: any}

One register value when index is supplied; otherwise a table of frame slots.

Usage notes

Stack slot positions are implementation details; inspect a frame before assuming an index has a particular local variable.

Example

Luau

local function inspect(value)
    local slots = debug.getstack(1)
    print("Frame slots:", #slots, "argument:", value)
end
inspect("sample")