REST API to get Jenkins Global configuration

I am working on the automation of project creation in Jenkins and wrote a Python script for that. In the script, I am getting input from users for different fields like git credentials and SSH server and creating the job. For now, the user can provide any random input for these fields and the project will be created.

Do we have any REST API in Jenkins through which we can fetch the global configuration/parameters from Jenkins and verify user input against these parameters?

eg. While we take the SSH server name from the user we will verify it with Jenkins global SSH configuration and alert the user if the SSH server name is not from the configured ones.

why not use a credential parameter type, which will list the credentials that are available?

Thanks for answering, I wrote a Python script to create the project in Jenkins, I am preparing an XML file and creating the project by posting it through REST API. While taking input in Python script I need some REST API that can fetch Global parameters from Jenkins and verify user input.

We have plugins in Jenkins, like - Publish Over SSH.
Do we have some script like Groovy or something, through which we can list Plugin data, where we will have ‘configured server names’ and all?