rest/api/2/issue/<issue-id>/transitions returns empty array - jira

Question

I've created an issue that follows this workflow:
When I call rest/api/2/issue/<issue-id>/transitions after creating an issue (which is in OPEN status now) it returns the following JSON:
{
"expand": "transitions",
"transitions": [
{
"id": "4",
"name": "Start Progress",
"to": {
"self": "URL",
"description": "This issue is being actively worked on at the moment by the assignee.",
"iconUrl": "URL",
"name": "In Progress",
"id": "3",
"statusCategory": {
"self": "URL",
"id": 4,
"key": "indeterminate",
"colorName": "yellow",
"name": "In Progress"
}
},
"fields": {}
}
]
}
When I make the same call after I change the issue status to "IN PROGRESS" I get back
{
"expand": "transitions",
"transitions": []
}
My questions are:
In the first response shown above, I expected the transitions to "CLOSED" and "RESOLVED" along with the one to "IN PROGRESS". But I only get back the one leading to "IN PROGRESS". Why?
I expected the second response to contain the transitions to "CLOSED", "RESOLVED" and "OPEN", but it returns an empty array. Why?
Please explain the responses from this API
What call should I make to get the next possible transitions?

Answer 1

This is probably a permission issue. The API only shows the transitions that are available to the current user, thus if you are not allowed to execute the CLOSE or RESOLVE transitions due to conditions in the project workflow, they will not appear in the JSON object.
See getTransitions from the JIRA REST API :
Get a list of the transitions possible for this issue by the current user, along with fields that are required and their types.
In order to get the transitions, you can either log in with an account that has the required permissions (check the corresponding workflow) or modify the conditions of the transition in this workflow.