| `environment` | **{check-circle}** | string (max 32 chars) | Name of the source environment, such as `production` or `staging` |
| `source` | **{check-circle}** | string (max 32 chars) | Name of the source application, such as `gitlab-rails` or `gitlab-javascript` |
| `plan` | **{dotted-circle}** | string (max 32 chars) | Name of the plan for the namespace, such as `free`, `premium`, or `ultimate`. Automatically picked from the `namespace`. |
| `extra` | **{dotted-circle}** | JSON | Any additional data associated with the event, in the form of key-value pairs |