How to post an Instagram carousel and Story from one set of slides

The two shapes

Carousels and Stories have different frames. Carousels in UGC API are cropped to 4:5 (1080x1350). Stories are full-screen 9:16 (1080x1920). One set of slides can serve both if you design for it.

• Design at 1080x1920.
• Keep all text and key visuals inside the center 1080x1350 area. That area survives the 4:5 crop.
• Keep the top and bottom 250px of the Story frame free of text, since Instagram draws the profile bar and reply field there.
• The center 4:5 area already sits inside those margins, so one rule covers both.

How Meta's API builds a carousel

1. Create a child container for each image with is_carousel_item=true.
2. Create a parent container with media_type=CAROUSEL and the list of child IDs.
3. Wait for the parent to reach FINISHED, then media_publish it.

Meta allows up to 20 items per carousel and crops all items to the first item's aspect ratio. A carousel counts as one post toward the account's 24-hour limit.

Stories are separate: one STORIES container per frame, each published on its own. Each frame counts toward the 24-hour limit.

With UGC API: one request

curl https://ugcapi.dev/v1/posts \
  -H "Authorization: Bearer ugc_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "accounts": ["acc_ig_01"],
    "format": "slideshow",
    "media": [
      "https://cdn.example.com/c/1.jpg",
      "https://cdn.example.com/c/2.jpg",
      "https://cdn.example.com/c/3.jpg",
      "https://cdn.example.com/c/4.jpg",
      "https://cdn.example.com/c/5.jpg",
      "https://cdn.example.com/c/6.jpg"
    ],
    "caption": "6 desk upgrades under $30. Save this for later.",
    "options": { "instagram": { "story": true, "story_slides": "first" } }
  }'

We publish the carousel, then the first slide as a Story. Credits: 2. With story_slides: 'all' you get 6 Story frames in order, for 7 credits.

First slide or all slides?

Make the Story frames work

• Add a small 'New post' marker to the first frame when it's a teaser.
• Number frames ('1/6') in a full sequence so viewers keep tapping.
• End the carousel with a save or follow prompt. In Stories, the last frame can say 'Full list on my profile'.
• Interactive stickers aren't available through Meta's API, so put calls to action in the image.

Add TikTok and Facebook

Add TikTok and Facebook account IDs to accounts and the same slides become a TikTok photo post and a Facebook multi-photo post. Turn on tiktok.auto_music so the TikTok version isn't silent. See the slideshow API and posting a TikTok slideshow via API.

Checklist

1. Account is a Business or Creator account.
2. Slides are JPEG, 1080x1920, text in the center 4:5 area.
3. 20 slides or fewer.
4. Story frame count fits the account's day.
5. Webhook handler stores each permalink.

For Story-specific details, see Instagram Story API and the Story guide.

Carousels vs Reels for UGC

Carousels are slower to make an impression than Reels but often earn saves and shares, since people come back to lists and how-tos. Many UGC teams run both from the same idea: a talking-head Reel for reach and a carousel version for saves. With UGC API that is two posts, one video and one slideshow, which you can schedule on different days for the same account. Track which one brings more profile visits before you commit to a format mix.