Tradier supports a couple different response formats. The way you should request a specific format is using the standard HTTP header Accept
.
This is the default format of the API due to its ubiquity in the financial space. You can omit or use the following Accept header to get XML: application/xml
Note: XML format will be removed in future versions of all Tradier APIs.
JSON format is lightweight and readable. It is recommended you use this format for your requests. You should use the following Accept header to get JSON: application/json
All APIs support GZip compression if sending the appropriate headers. For example:
Accept-Encoding: gzip