The REST API supports responses in several formats. You specify the response format using the query parameter f. A list of valid formats is included below where f is a parameter.
To view the Services Directory page for the root directory an ArcGIS Spatial Data Server, use a derivative of the following URL:
Note that since "html" is the default value, you are not required to include this parameter in the URL. This means that the above URL is equivalent to the following URL:
To retrieve the information in a JSON object, you would use the following URL:
You can also reference a callback function in the URL:
If you want the JSON object to be more readable, you can use pjson. You should not include this parameter in your production applications as it will affect performance. Use this parameter for debugging purposes only.