# External References

External References allows users see which objects (one of `Assignment`, `BillingMilestone`, `CustomField`, `CustomFieldChoice`, `CustomFieldSet`, `CustomFieldValue`, `Estimate`, `EstimateScenario`, `EstimateScenarioResource`, `Expense`, `ExpenseBudget`, `Invoice`, `Participation`, `Post`, `RateCard`, `Role`, `Skill`, `StatusReport`, `Story`, `StoryAllocationDay`, `Submission`, `SurveyAnswer`, `SurveyQuestion`, `SurveyResponse`, `SurveyTemplate`, `TimeEntry`, `TimeOffEntry`, `User`, `Vendor`, `Workspace`, `WorkspaceAllocation`, `WorkspaceGroup`, or `WorkspaceResource`
are synced with third party systems. This allows you to view the sync status of items in
addition to the integration specifics for a synced object.
Objects that are synced with a third party system have external integration
attributes that include the corresponding ID of the third-party object with
which it is synced, a link that allows you to view the object in the third
party system, the status of the external object in the external system,
the status of the sync, and a link to exceptions.

 - [GET /external_references](https://developer.kantata.com/kantata/specification/external-references/get%20external%20references.md): Returns external references, for objects of particular types, that are synced with the third-party systems. This endpoint returns structured External Reference objects. As with all Kantata OX API endp
 - [POST /external_references/create_or_update](https://developer.kantata.com/kantata/specification/external-references/create%20or%20update%20external%20reference.md): This endpoint returns structured External Reference objects. As with all Kantata OX API endpoints, the returned data will be referenced in sorted order in the `results` array and will be indexed by ID
 - [DELETE /external_references/{id}](https://developer.kantata.com/kantata/specification/external-references/delete%20external%20reference.md): The response will contain no content and an HTTP 204 status code if the request was successful, or a [standard Kantata OX error message](#section/Errors) explaining why the object could not be deleted