This function is a synchronous wrapper around PerformHttpRequest which will await the data internally, preventing the need for callbacks. It's available on server build 9515 and newer
PerformHttpRequestAwait(string url, string method = 'GET', string data = '', table headers = {}, table options = { followLocation = true })
local errorCode, resultData, resultHeaders, errorData = PerformHttpRequestAwait("http://some-cool-url.here/some-important-document.txt")
print("Error Code: " .. errorCode)
print("Result Data: " .. resultData)
print("Result Headers: " .. resultHeaders)
print("Error Data: " .. errorData)