Bulk update of issues

Trying to figure out how to bulk update issues in the same way that Jira cloud does. Looked through the documentation but it was not clear how to do bulk updates. For instance, if I have 150 issue ids, and I want to:
Add a label
Change the assignee
Add a comment

Is there a single endpoint that one can use? Jira cloud makes it appear that it submits an update and then gets status updates as to how many of the issues were updated. Its not clear if this is completely done via the UI, ie does it make 450 calls? Does it break the calls down into chunks?

I know I could run a bulk update and look at the calls made, but I’d rather not touch our instance.

Any leads to the right section of the API docs would be appreciated

In short, no such API is available. The request has been gathering interest since 2018.

There is only a bulk create currently.

So how does Jira front end do bulk updates? Does it make a call for each endpoint?

Of course the Cloud site can, you can simply open developer tools and look at it.

I bulk add comment “Bulk comment” on two issues and this is what I found:

{"issueKeys":["PROJ1-53","PROJ1-54"],"operation":"EDIT","payload":{"fields":["comment"],"params":{"comment":"Bulk comment","commentProperty":"[{\"key\":\"sd.public.comment\",\"value\":{\"internal\":\"true\"}}]"}}}

But the thing is, there is no available documentation and it can change without warning.

Maybe bulk update via a CSV file instead: