A stream key is a unique identifier that tells the ingest server which stream you are sending. It looks like a random code, e.g. f3d397f02fao94685600zo8a6adggfa.

For RTMP, it is typically a random code the last part of the ingest URL. In the above example, it could look like rtmp://ingest-rtmp.eu.mottostreaming.com:1935/live/f3d397f02fao94685600zo8a6adggfa.

For SRT, the stream key is also included, but is often a so-called query parameter in a URL that may contain other information as well. For example, srt://ingest.global.mottostreaming.com:6001?streamid=a8ff4m1a-0ddc-e8f9-338m-fcbb17e1f254&passphrase=f3d397f02fao94685600zo8a6adggfa&latency=1000000.

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See also