How do I use the Cirium Flex APIs? Jeff Moyer June 10, 2020 21:44 Updated Follow The web services are RESTful, returning either XML or JSON. We also offer SOAP endpoints. The interactive documentation allows you to enter your search criteria, then cut/paste the correct syntax into your custom software. More information: https://developer.flightstats.com/api-docs/how_to Related articles How do I register to use the APIs? Where can I find the Cirium Flex API reference documentation? What is a Cirium API and when would I use one? What is the Flight Features API? How do I add authentication to my Alerts API callbacks? Comments 0 comments Article is closed for comments.