Luau API

xllify.ExcelFunction()

Register a function for Excel, aka: xllify.fn

Usage

xllify.ExcelFunction(metadata, function_body)
xllify.fn(metadata, function_body)

Metadata fields:

• name (string) - Excel function name (e.g., "MyFunc")

• description (string) - Function description (optional)

• category (string) - Excel category (optional)

• execution_type (string) - "sync" or "async" (default: "sync")

Basic example

xllify.ExcelFunction({
    name = "ADD",
    description = "Add two numbers",
    category = "Math"
}, function(x, y)
    return x + y
end)

Async example

xllify.ExcelFunction({
    name = "DELAYED_MESSAGE",
    description = "Returns a message after a delay",
    execution_type = "async"
}, function(seconds, message)
    async.sleep(seconds)  -- Non-blocking sleep
    return message
end)

---

Built-in properties

xllify.version

Get xllify version:

Example

xllify.ExcelFunction({
    name = "GetVersion"
}, function()
    return xllify.version
end)

---

Async functions

Async functions (with execution_type = "async") can use non-blocking operations via the async namespace.

async.sleep()

Non-blocking sleep (async functions only):

Signature

async.sleep(seconds)

Example:

Countdown example

xllify.ExcelFunction({
    name = "COUNTDOWN",
    execution_type = "async"
}, function(start)
    for i = start, 1, -1 do
        async.sleep(1)
    end
    return "Done!"
end)

async.http_get()

Non-blocking HTTP GET (async functions only, Windows only):

Signature

result = async.http_get(url)

Returns a table with:

• status - HTTP status code

• body - Response body (if successful)

• error - Error message (if failed)

Example

xllify.ExcelFunction({
    name = "FETCH_DATA",
    execution_type = "async"
}, function(url)
    local result = async.http_get(url)
    if result.error then
        error(result.error)
    end
    return result.body
end)

async.http_post()

Non-blocking HTTP POST (async functions only, Windows only):

Signature

result = async.http_post(url, body, content_type)

Parameters:

• url - URL to POST to

• body - Request body

• content_type - Content-Type header (optional, defaults to "application/json")

Returns same table structure as http_get().

---

Blocking functions

For non-async (sync) functions, blocking versions are available globally.

sleep()

Blocking sleep (sync functions only):

Signature

sleep(seconds)

http.get()

Blocking HTTP GET (sync functions only):

Signature

result = http.get(url)

http.post()

Blocking HTTP POST (sync functions only):

Signature

result = http.post(url, body, content_type)

---

Standard libraries

All standard Luau libraries are available:

-- String
string.upper, string.lower, string.format, etc.

-- Table
table.insert, table.remove, table.concat, etc.

-- Math
math.sin, math.cos, math.sqrt, etc.

-- OS
os.time, os.date, etc.

---

Logging

Use the log namespace to write log messages:

log.trace("Trace message")
log.debug("Debug message")
log.info("Info message")
log.warn("Warning message")
log.error("Error message")
log.critical("Critical message")

---

Excel types

Excel Type	Luau Type
Number	number
String	string
Boolean	boolean
Range	table (2D array)
Empty	nil

---

Error handling

Use error() to return errors to Excel:

Example

xllify.ExcelFunction({
    name = "DIVIDE"
}, function(a, b)
    if b == 0 then
        error("Cannot divide by zero")
    end
    return a / b
end)

Excel shows: #ERROR: Cannot divide by zero