Instagram Reels API limits: 3 collaborators, no carousel, audio tags

Three limits on Meta's IG User Media reference shape a Reels batch: collaborators takes a list of up to 3 Instagram usernames, Reels cannot appear in carousels, and music tagging is available only for original audio (read 2026-10-02). None of the three is a property of the video file, so they are decisions for your publish step.

How many collaborators can a Reel have?

Up to 3 usernames, passed as collaborators. The page says the field works for Feed images, Reels and Carousels, and is not supported for Stories. A related field, branded_content_sponsor_ids, takes at most 2 IDs for a partnership label, which is a separate limit.

Can I put a Reel in a carousel?

No. The Reels limitations say Reels cannot appear in carousels, and the carousel section adds that to create carousel item containers you create image or video containers instead, because reels are not supported there. A carousel holds up to 10 images, videos, or a mix.

If a batch mixes formats, split it up front: a Reel container for the 9:16 clip, and image or video items for the carousel. For stills taken from one clip, video frames can extract up to 24 per call.

Does generated music count as original audio?

The page does not say. It states only that music tagging is available for original audio and that audio_name can be renamed once, either when creating the Reel or later from the audio page. If your clip carries a soundtrack you generated and mixed in, test one Reel on a real account and see how Instagram treats the audio before you plan around music tags.

What should I do?

Cap collaborators at 3 in your own validation, route carousel items through image or video containers, and treat music tags as unavailable until a test proves otherwise. Probe the video itself with video inspect for the spec items it can see.