API for Live and Replay video stream, manage and control

May I know what are the API call that i can use? i am overwhelmed by the documentation

Are the API call free to use? What are the charges like?

There is a sample called WebRTC. This sample uses a RESTful API, but the sample is a pre-release (for VMS 2022 R3) and stable release will be 2023 R1. Also, you will see only live video in this sample, playback does not work.

https://doc.developer.milestonesys.com/html/index.html?base=samples/protocolsamples/webrtc_javascript/readme.html&tree=tree_3.html

But this ImageViewerWpfControl and PlaybackWpfUserControl sample might be interesting for you. It can display live and playback video through the sample.

https://doc.developer.milestonesys.com/html/index.html?base=samples/componentsamples/imageviewerclient/readme.html&tree=tree_2.html