Postman

Postman is a free application to streamline API calls for development and test with an easy-to-use UI. It is capable of saving libraries of API calls which makes it easy to manage, save, and load API workflows.

You can download Postman from its website here.

1264 — Postman workspace, with a login example

Postman automatically saves the session cookie after the initial login, so subsequent API calls can be made to the device until logout.

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Proxy and SSL Settings
By default, Postman enables SSL certificate verification. To change the default behavior, in Postman, go to Settings -> General -> 'SSL certificate verification' and turn the setting off.
To add proxy information, go to Settings -> Proxy