Facebook Reels API: Publish Facebook Reels Automatically

Facebook Reels are recommended to people who don’t follow your Page, which makes them one of the cheapest sources of reach left on Facebook. If you already make vertical video for TikTok and Instagram, you’re one field away from posting it as a Facebook Reel too. This guide shows how to publish Reels through the Creator OS API, CLI or from Claude, with a title, cover, first comment and schedule.

  clip.mp4 (9:16)
      |
      +--> Instagram Reel
      +--> TikTok
      +--> YouTube Short
      +--> Facebook Reel   contentType: "reel"
                           title: "Sourdough in 60 seconds"
                           firstComment: "Recipe: https://..."

The same clip, one more Reel

The fields

contentType: "reel": publishes a single vertical video as a Reel instead of a feed video.
title: the Reel’s title, separate from the caption in content.
firstComment: posted right after the Reel goes live. Good for links.
pageId: which Page, when you manage several.
geoRestriction: show it only in up to 25 countries.
Cover: the post-level cover becomes the video thumbnail on Facebook.
facebookSettings.draft: create it as an unpublished draft in Facebook’s Publishing Tools instead.

POST /v1/posts
{
  "content": "60-second sourdough. Save this for Sunday.",
  "media": ["med_..."],
  "cover": "med_cover",
  "platforms": [{
    "platform": "facebook",
    "account_id": "acc_...",
    "options": {
      "contentType": "reel",
      "title": "Sourdough in 60 seconds",
      "firstComment": "Full recipe: https://go.creatoros.ca/..."
    }
  }]
}

Using the simple form ("platforms": ["facebook", "instagram", "tiktok"]) with a vertical video, Creator OS applies each platform’s short-video settings for you.

From Claude

With the Facebook MCP server connected:

“Post clip.mp4 as a Facebook Reel on the bakery Page at noon, title ‘Sourdough in 60 seconds’, recipe link in the first comment.”
“Every short I post to Instagram this week, also post as a Facebook Reel.”
“Which of my Facebook Reels reached the most non-followers this month?”

What works on Facebook Reels

Same edit, native caption. Facebook audiences skew older; captions that explain a bit more tend to do better than TikTok-style one-liners.
Hook in the first second, like every short platform.
Use the title. It shows under the Reel and helps search.
Answer comments. Facebook comments often turn into Messenger conversations, which is where local businesses close sales. See all your DMs in one inbox.

Limits

Reels are a single vertical video. Carousels and Stories are separate content types.
contentType can’t be combined with link carousels.
Drafts in Publishing Tools expire after about 30 days.

Cross-post everything in one call

The real win is posting one short to Reels, TikTok, Shorts and Facebook Reels at once. See cross-posting short video.

Prefer to watch? The KevBuildsApps YouTube channel walks through builds like this one, start to finish.

Get started

Creator OS plans start at $19.99/month with the API, MCP server and CLI. Sign up, connect your Facebook Page, and post your next Reel everywhere.