How to add events into Emails & Activities in the API as another person?

In the example above, the contact, Sam Jones <sam@apple.com> has emailed someone. The avatar and heading are for Sam.

If I was to add an activity on the contact’s behalf, I’d want to add the contact’s avatar & name rather than my own (which is what would happen by default).

Is there a way to add that the Contact as the person who performed the activity rather than the person who added it using the API?

So far, this seems to be a limitation of the create_timeline_item mutation.

Dev Sidekick says:

Looking at the available arguments for create_timeline_item, there is no parameter to specify a different user as the activity performer. The mutation's arguments are:

• item_id, custom_activity_id, title, timestamp (required)
• content, summary, time_range, url, phone, location (optional)

[create_timeline_item]

None of these allow you to attribute the activity to a specific contact or user other than the API caller. The knowledge sources do not mention any way to override the author/performer of a timeline item via the API.

You may want to work around this by including the contact's name in the title, summary, or content fields to make it clear the activity was performed on their behalf — but this would be purely cosmetic text, not a true attribution change.