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Guides

Creating Reels

Reels are short-form vertical videos. OmniSocials supports reels on Instagram, Facebook, YouTube (as Shorts), and TikTok. A single POST /posts/create call with type: "reel" can fan out a reel to all four platforms at once.

Supported channels

Channel ID	Platform	Format	Max duration
instagram	Instagram Reels	Vertical 9:16	90 seconds
facebook	Facebook Reels	Vertical 9:16	90 seconds
youtube	YouTube Shorts	Vertical 9:16	60 seconds
tiktok	TikTok	Vertical 9:16 or 16:9	10 minutes

Calling with type: "reel" and a channel that does not support reels (LinkedIn, X, Pinterest, etc.) returns 400.

Minimal example

Code
curl -X POST https://api.omnisocials.com/v1/posts/create \
  -H "Authorization: Bearer $OMNISOCIALS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "reel",
    "content": { "default": "New drop 🔥" },
    "accounts": ["your-instagram-account-id"],
    "media_urls": ["https://example.com/reel.mp4"]
  }'

Reels always require a single video file. Image-only or multi-video reel requests return 400.

Cross-posting a reel across all four platforms

Include every channel ID in accounts and use per-platform options for each platform's specific requirements.

Code
{
  "type": "reel",
  "content": {
    "default": "Behind the scenes from today's shoot",
    "tiktok": "POV: behind the scenes 🎬",
    "youtube": "How we filmed today's shoot #shorts"
  },
  "accounts": [
    "your-instagram-account-id",
    "your-facebook-page-account-id",
    "your-youtube-account-id",
    "your-tiktok-account-id"
  ],
  "media_urls": ["https://example.com/vertical-video.mp4"],
  "instagram": {
    "share_to_feed": true,
    "thumbnail_type": "from-video",
    "thumb_offset": 3000
  },
  "youtube": {
    "title": "Behind the scenes",
    "privacy_status": "public",
    "notify_subscribers": true
  },
  "tiktok": {
    "privacy_level": "PUBLIC_TO_EVERYONE",
    "disable_duet": false,
    "disable_stitch": false
  }
}

Every platform-specific key only applies to its own channel. Instagram ignores the youtube and tiktok blocks. YouTube ignores the instagram and tiktok blocks. And so on.

Platform-specific options

Each reel-capable platform has its own set of options. Pass them under the matching channel ID key.

Instagram reel options

Field	Type	Description
instagram.share_to_feed	boolean	Also show the reel on the profile feed grid
instagram.thumbnail_type	string	from-video or from-library
instagram.thumb_offset	number	Timestamp in milliseconds, used when thumbnail_type is from-video
instagram.cover_url	string	URL of a custom cover image, used when thumbnail_type is from-library

YouTube Shorts options

Field	Type	Description
youtube.title	string	Video title, max 100 characters. Defaults to "YouTube Short".
youtube.tags	array	Discovery tags. Max 500 characters total.
youtube.privacy_status	string	public, private, or unlisted
youtube.category_id	string	YouTube category. Defaults to "22" (People & Blogs).
youtube.made_for_kids	boolean	COPPA disclosure. Disables comments and interactions when true.
youtube.notify_subscribers	boolean	Send the subscriber notification when published
youtube.contains_synthetic_media	boolean	Disclose AI-generated content

TikTok options

Field	Type	Description
tiktok.privacy_level	string	Required. PUBLIC_TO_EVERYONE, MUTUAL_FOLLOW_FRIENDS, FOLLOWER_OF_CREATOR, SELF_ONLY
tiktok.disable_comment	boolean	Disable comments on the reel
tiktok.disable_duet	boolean	Disable duets
tiktok.disable_stitch	boolean	Disable stitches
tiktok.is_aigc	boolean	Disclose AI-generated content
tiktok.brand_content_toggle	boolean	Mark as paid partnership / branded content

TikTok requires privacy_level on every reel. Omitting it returns 400.

Facebook Reels

Facebook has no specific reel option fields. The default reel body works.

Different video per platform

Sometimes you want a slightly different cut for each platform (e.g. a shorter version for YouTube Shorts where the limit is 60 seconds, and a longer cut for TikTok where the limit is 10 minutes). Use the per-platform media_urls shape:

Code
{
  "type": "reel",
  "content": { "default": "Full tutorial" },
  "accounts": [
    "your-youtube-account-id",
    "your-tiktok-account-id"
  ],
  "media_urls": {
    "youtube": ["https://example.com/tutorial-60s.mp4"],
    "tiktok": ["https://example.com/tutorial-full.mp4"]
  },
  "youtube": {
    "title": "Quick tutorial #shorts",
    "privacy_status": "public"
  },
  "tiktok": {
    "privacy_level": "PUBLIC_TO_EVERYONE"
  }
}

Media requirements

Platform	Format	Aspect	Duration	File size
Instagram	MP4	9:16	3 to 90 seconds	Up to 1 GB
Facebook	MP4	9:16	3 to 90 seconds	Up to 1 GB
YouTube Shorts	MP4	9:16	Up to 60 seconds	Up to 256 MB
TikTok	MP4 or MOV	9:16 or 16:9	3 seconds to 10 minutes	Up to 4 GB

Videos outside these constraints are rejected at publish time. OmniSocials does not transcode, trim, or re-encode.

The safest format for cross-platform reels: MP4, H.264 codec, 1080 × 1920 vertical, under 60 seconds, under 100 MB. That passes every platform's requirements.

Thumbnails and cover images

Each platform picks the reel cover differently:

• Instagram: default is the first frame. Override with instagram.thumb_offset (pick a video frame) or instagram.cover_url (supply a custom image).
• Facebook: default is the first frame. No override currently supported through the API.
• YouTube Shorts: YouTube auto-selects the thumbnail. Custom thumbnails for Shorts are not supported by the YouTube API.
• TikTok: TikTok auto-selects a frame. Custom covers can be set under tiktok.video_cover_timestamp_ms (timestamp in milliseconds, pick a frame).

Scheduling reels

Reels are schedulable the same way as feed posts. Add scheduled_at (ISO 8601 UTC).

Code
{
  "type": "reel",
  "content": { "default": "Friday feature" },
  "accounts": [
    "your-instagram-account-id",
    "your-tiktok-account-id"
  ],
  "media_urls": ["https://example.com/reel.mp4"],
  "tiktok": { "privacy_level": "PUBLIC_TO_EVERYONE" },
  "scheduled_at": "2026-04-18T14:00:00Z"
}

Limitations

• Reels must have exactly one video. Multi-video or image reels are rejected.
• type: "reel" is rejected on platforms that do not support reels. Mixing reel-capable and non-reel-capable channels in the same accounts array returns 400.
• YouTube Shorts require the channel to be monetization-eligible on YouTube. Non-eligible channels can still publish but the video may appear as a regular video instead of a Short.
• TikTok branded-content reels (brand_content_toggle: true) go through TikTok's review workflow and may take longer to publish.
• Instagram enforces a 75-day maximum lookahead for scheduled reels. Scheduling further out returns 400.

Related reading

• Creating Posts for the full field reference
• Cross-Posting for the one-request-many-platforms model
• Creating Stories for the ephemeral story workflow
• Instagram, TikTok, YouTube for full per-platform specs