This page will show you, the provided (starting with version 4.0) Rest API to create/read/update/delete metadata values.
Be aware that:
- most of the calls required a logged in user session. (Further details regarding authentication: https://developer.atlassian.com/jiradev/jira-apis/about-the-jira-rest-apis/jira-rest-api-tutorials/jira-rest-api-example-cookie-based-authentication )
- the user interface displays a maximum of 500 metadata values for a project/component/version/user/group, but with the rest interface you can manage more than 500.
Rest API Documentation
Current Rest API Documentation
Base path for the Rest API: Jira_Base_Url/rest/metadata/1.0
e.g. get the first 20 metadata for project JM (as project-admin): https://jira.atlassian.internal/rest/metadata/1.0/project/JM?includeHidden=true&startAt=0&maxResults=20