Are ID fields of Graph objects globally unique?

Question

We are using Graph api to sync user's calendar items, tasks and emails.

Each of those objects have 'id' property. Are those globally unique? Is there a situation that for example Appointment and Email object can have same ID?

Answer 1

Hi @Zarko Petrovic

Yes, the object id is a unique identifier used to refer to the target object, it is impossible for different objects to have the same object id.

However, object ids are not immutable. For example, this value changes when mail is moved from one container (such as a folder or calendar) to another. To change this behavior, use the Prefer: IdType="ImmutableId" header. See Get immutable identifiers for Outlook resources for more information.

Hope this helps.

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Answer 2

Hi Zarko,

Good afternoon and thank you for the question. Please create a ticket since we need to verify this with our product engineers and make sure that we will be providing correct information.

Thanks!