Scenario

In JIRA Cloud, it's possible to create and transition an issue using this endpoint:

/rest/api/2/issue

Sample JSON body:

{ 
	"fields": {
		"project": {
			"key": "TEST"
		},
		"summary": "Test Summary",
		"description": "Test Description",
		"issuetype": {
			"name": "Story"
		}
	},
	"transition": {
		"id": "21"
	}
}

According to Cloud REST API doc, it seems the transition parameter has been enabled and works as intended.

This however doesn't work in JIRA Server. With the same endpoint and JSON body, an issue is created but not transitioned. According to Server REST API doc, it seems transition hasn't been enabled.

Suggestion

1. Enable transition for JIRA Server REST API so that an issue can be created and transitioned with this single endpoint:

   /rest/api/2/issue

2. Document this feature clearly in the respective docs above.
   It's even better to have a full checklist of differences between Cloud and Server REST APIs.

Workaround

For JIRA Server, once an issue is created, take note of its ID in the response, e.g.:

{
    "id": "12407",
    "key": "TEST-31",
    "self": "http://10.60.2.88:8770/jira770/rest/api/2/issue/12407"
}

then use this (POST) endpoint to transition it:

/rest/api/2/issue/12407/transitions

Sample JSON body:

{ 
	"transition": {
		"id": "21"
	}
}