Listing All JIRA Transitions via API

I'm looking to set up smart commits in JIRA, but my developers want to know all the options for their transitions. In order to help them, I'd like to print a cheat-sheet of all transition names (I trust they are smart enough to figure out what does what from there).

But when I look through the REST API documentation, I can only find a way to get the list of transitions for a particular issue (presumably via its status). Is there a way to get the list of all transitions that any ticket can take at any point in its workflow?

You can get all transitions for project with /rest/api/2/project/{projectIdOrKey}/statuses endpoint. Here is response example, look at "statuses" array:

[
    {
        "self": "http://localhost:8090/jira/rest/api/2.0/issueType/3",
        "id": "3",
        "name": "Task",
        "subtask": false,
        "statuses": [
            {
                "self": "http://localhost:8090/jira/rest/api/2.0/status/10000",
                "description": "The issue is currently being worked on.",
                "iconUrl": "http://localhost:8090/jira/images/icons/progress.gif",
                "name": "In Progress",
                "id": "10000"
            },
            {
                "self": "http://localhost:8090/jira/rest/api/2.0/status/5",
                "description": "The issue is closed.",
                "iconUrl": "http://localhost:8090/jira/images/icons/closed.gif",
                "name": "Closed",
                "id": "5"
            }
        ]
    }
]

But it doesn't give you exactly list of transitions that any issue can take at any time, and I'm not sure that such method exist in API.