> I know there are a number of headers used to control cross-site access to websites
Mostly these headers are designed around preventing reading content. Sending content generally does not require anything.
(As a kind of random tidbit, this is why csrf tokens are a thing, you can't prevent sending so websites test to see if you were able to read the token in a previous request)
This is partially historical. The rough rule is if it was possible to make the request without javascript then it doesn't need any special headers (preflight)
Mostly these headers are designed around preventing reading content. Sending content generally does not require anything.
(As a kind of random tidbit, this is why csrf tokens are a thing, you can't prevent sending so websites test to see if you were able to read the token in a previous request)
This is partially historical. The rough rule is if it was possible to make the request without javascript then it doesn't need any special headers (preflight)