how do i detect httpservice:postasync() failure?

[wintry scaffold]

PostAsync returns the body of the response as a string. Could be your desired response or an error message. No way to really tell

If you want more details, like a response code, you'd need to use RequestAsync that requires more setup

[vestal frost]

you could use pcall

so
local s,e =pcall(function() return httpservice:PostAsync() end) if not s then print(e) end

[pale zodiac]

i tried this but it still fails sometimes

[vestal frost]

if it fails you could try to get it again

[pale zodiac]

No I mean is says success but there was a error

[wintry scaffold]

print the error message, what is it

[pale zodiac]

it is 429 i think

[wintry scaffold]

That means you're sending too many requests to the server at that URL. Most servers don't like having too many requests from one computer, so it limits it.

[pale zodiac]

but it should still work if pcall right?

[wintry scaffold]

Nope.

The pcall catches the error in sending it, like the function itself doesn't return any runtime errors.

The error you received is a network error, which Roblox doesn't consider an error (as the request still reached the destination and was processed)