403 error, api key not working,

Anyone else ever had this issue? Ive been trying to fix this and something is not right. for what I am doing my app does not require oauth or callers … how else can I do this?

“error”: {
“code”: 403,
“message”: “Method doesn’t allow unregistered callers (callers without established identity). Please use API Key or other form of API consumer identity to call this API.”,
“errors”: [
{
“message”: “Method doesn’t allow unregistered callers (callers without established identity). Please use API Key or other form of API consumer identity to call this API.”,
“domain”: “global”,
“reason”: “forbidden”