Which REST operations on issues will add the user as a watcher?

[Mike Howells]

Some operations done on issues via REST appear to add the user as a watcher. This is a problem if the user is an automated service as the service's account starts getting Jira notification emails. 

Which operations add the user as a watcher? Is it possible to prevent a user becoming a watcher?

[Alexey Matveev]

Hello,

A user becomes a watcher, if this user creates an issue in Jira. But you can disable this feature in the user profile. You can find more info here:

https://confluence.atlassian.com/adminjiraserver071/configuring-the-user-default-settings-802592314.html