For the JSON Client, use the endpoint "http://mail.yahooapis.com/ws/mail/v1.1/jsonrpc", set the content-type and pass the OAuth headers. For more details, refer to the PHP files ListFolder.php or GetUserData.php.

An Accept header is necessary if you want to get back a response in JSON if an error occurs. A JSON response for an expired token will appear as below:

If Accept is not set then response would be in XML.

Below is a sample OAuth header ($oauthHeaderForJson) before you initiate the JSON or SOAP client .

Use WSDL to construct your SOAP client. You must provide a location URL to your SOAP toolkit and attach the OAuth headers returned from the final OAuth step.