I want to integrate my integrate my Salesforce Org to this Attendance device to store all the attendance records.
I am already familiar with socket based PHP libraries and SDKs but I am required to Integrate my SF Org directly with Zkteco attendance device in order to store date-time records into the org, is there an API documentation for REST or SOAP integration?
Modern ZK Devices communicate with cloud services using PUSH protocol.You can check your device, under network configuration, if there is a way to set an ADMS server. If there is, it means it supports cloud services, otherwise, only standalone SDK is available.
PUSH protocol communication is similar to REST, however, transfer between the device and the server is simpler, not using JSON neither XML.
Unfortunately, you have to purchase information about PUSH protocol from ZKTeco or hire a third party person who could do the development for you. For that reason, you will not be able to find much information over the Internet.
The only site that has some information is this: https://docs.nufaza.com/docs/devices/zkteco_attendance/push_protocol/. If you read it, you can try to deduce how to manage it by yourself.
If you have other question after reading that page, you can ask me here.
BTW, that site is not mine, but it was a good reference when I learned PUSH protocol.