What tool should I be using to inspect the JSON data returned as a result of making a rest api call to the sharepoint online or Office365 site. The browsers return xml and I am having issues using fiddler. It comes back with error messages about authentication or permission denied.
Login with the credentials of SharePoint tenancy and make sure your user is authenticated to do the operation. I prefer chrome to this operation and recommend to use "Advanced REST client" or Postman REST extension. Finally, make sure your request headers are used accordingly.
'Accept': 'application/json;odata=verbose', 'Content-Type': 'application/json;odata=verbose', 'X-RequestDigest': xx, 'X-HTTP-Method': 'xx', 'If-Match': "xx"
This should work and if this helped, dont forget to mark which make others life easy.
Thanks for all the responses, however I have not heard from anyone about installing and enabling the "Postman Interceptor" (for Postman) or "ARC Cookie Exchanger" for Advanced REST Client. Without enabling these Chrome extensions the authenticaton will not work even if I had logged on the 0365 site in Chrome. Following are the screenshots from both pages on how to enable them: