Same post across all 9 platforms

What happens when you post the same core content to all 9 live platforms at once? This guide walks through a real multi-platform post — showing what adapts per platform, what fails, and how to handle it.

The base content

Campaign: Product launch announcement
Core message: “Announcing VoxBurst 2.0 — unified social scheduling across every platform.”
Media: One JPEG image at https://cdn.example.com/v2-launch.jpg
Goal: Post now to all 9 connected accounts

What each platform receives

Before creating the post, it helps to understand what each platform needs.

Platform	contentType	Media	Caption adaptation needed?	Notes
Instagram	`IMAGE` (required)	Required	Yes — keep under 2,200 chars	No text-only; always pass `contentType`
Twitter / X	`IMAGE`	Optional	Yes — must be ≤280 chars	Links count as 23 chars
LinkedIn	`IMAGE`	Optional	Yes — can be longer and more professional
Facebook	`IMAGE`	Optional	No
Threads	`IMAGE`	Optional	Yes — keep under 500 chars
YouTube	`VIDEO`	Required (video)	N/A	Cannot post image; skip or use a video
Bluesky	`IMAGE`	Optional	Yes — must be ≤300 graphemes
Mastodon	`IMAGE`	Optional	Yes — keep under 500 chars (default)
WhatsApp Business	`IMAGE`	Required for image posts	Yes — keep under 4,096 chars	Requires Business API access; `TEXT` posts also supported

YouTube requires a video. If you are posting an image-based launch, skip YouTube or prepare a separate video asset. Including a YouTube account in accountIds with only an image will fail for that platform while the others succeed.

The create_post call

Targeting 8 platforms (skipping YouTube for this image-based post):


create_post(
  content: "Announcing VoxBurst 2.0 — unified social scheduling across every platform.",
  accountIds: [
    "acc_instagram_abc",
    "acc_twitter_def",
    "acc_linkedin_ghi",
    "acc_facebook_jkl",
    "acc_threads_mno",
    "acc_bluesky_pqr",
    "acc_mastodon_stu",
    "acc_whatsapp_vwx"
  ],
  contentType: "IMAGE",
  mediaUrls: ["https://cdn.example.com/v2-launch.jpg"],
  platformOverrides: {
    "TWITTER": {
      "content": "VoxBurst 2.0 is live 🚀 One tool. Every platform. #SocialMedia #Launch"
    },
    "LINKEDIN": {
      "content": "Today we are shipping VoxBurst 2.0.\n\nWe rebuilt scheduling from the ground up — faster, more reliable, and truly cross-platform. If you manage social content at scale, this changes the workflow."
    },
    "THREADS": {
      "content": "VoxBurst 2.0 drops today. Unified scheduling. 9 platforms. One post."
    },
    "BLUESKY": {
      "content": "VoxBurst 2.0 — schedule across every platform from one place. Shipping today."
    },
    "MASTODON": {
      "content": "VoxBurst 2.0 is out. Cross-platform social scheduling, now unified. #VoxBurst #OpenWeb"
    },
    "WHATSAPP": {
      "content": "VoxBurst 2.0 is live — unified scheduling across every platform. Tap the image for details."
    }
  },
  firstComment: "#VoxBurst20 #ProductLaunch #SocialMedia",
  firstCommentDelay: 60
)

What gets the base caption: Instagram and Facebook (both support long captions and the base text fits).
What gets an override: Twitter/X (280-char limit), LinkedIn (professional tone), Threads (500-char limit), Bluesky (300-grapheme limit), Mastodon (500-char default), WhatsApp (conversational tone, no hashtags).
First comment: Instagram, LinkedIn, and YouTube support it. Facebook support is pending Meta API approval. Threads, Bluesky, Mastodon, and WhatsApp will silently ignore it.

What the response looks like


{
  "id": "post_launch_v2",
  "status": "publishing",
  "platforms": [
    { "platform": "instagram", "status": "pending" },
    { "platform": "twitter", "status": "pending" },
    { "platform": "linkedin", "status": "pending" },
    { "platform": "facebook", "status": "pending" },
    { "platform": "threads", "status": "pending" },
    { "platform": "bluesky", "status": "pending" },
    { "platform": "mastodon", "status": "pending" },
    { "platform": "whatsapp", "status": "pending" }
  ]
}

All 8 platforms are queued. Check results after a few seconds:


get_post(postId: "post_launch_v2")

A realistic outcome (some succeed immediately, one fails):


{
  "status": "partial",
  "platforms": [
    { "platform": "instagram", "status": "published", "platformPostUrl": "https://www.instagram.com/p/..." },
    { "platform": "twitter", "status": "published", "platformPostUrl": "https://x.com/..." },
    { "platform": "linkedin", "status": "published", "platformPostUrl": "https://www.linkedin.com/feed/update/..." },
    { "platform": "facebook", "status": "published", "platformPostUrl": "https://www.facebook.com/..." },
    { "platform": "threads", "status": "published", "platformPostUrl": "https://www.threads.net/..." },
    { "platform": "bluesky", "status": "published", "platformPostUrl": "https://bsky.app/profile/.../post/..." },
    { "platform": "mastodon", "status": "failed", "error": "Instance temporarily unavailable", "retryCount": 0 },
    { "platform": "whatsapp", "status": "published", "platformPostUrl": null }
  ]
}

7 published, 1 failed (Mastodon instance transient error). Status is partial.


retry_post(postId: "post_launch_v2")

Mastodon re-queues. Instagram through Bluesky are untouched.

Key observations across platforms

Aspect	What varies
Caption length	Twitter needs it short (280 chars). Bluesky counts graphemes. Mastodon varies by instance.
contentType	Only Instagram requires it explicitly. Others accept it but don’t mandate it for images.
First comment	Fires on Instagram, LinkedIn, YouTube. Facebook support is pending Meta API approval. Silently ignored on Threads, Bluesky, Mastodon, WhatsApp.
Media	All 8 platforms accept an image. YouTube would need a separate video post.
Character counting	Twitter links = 23 chars. Bluesky emoji = 1 grapheme. Everything else is character-based.
Partial failure	Expected and normal. `retry_post` handles it — never re-posts successful platforms.

Tell your agent

“Post our launch announcement to all connected accounts except YouTube. Use the shared image. Adapt the caption for each platform’s character limit and tone. Add a first comment with hashtags 60 seconds after publishing on platforms that support it.”

The agent will:

Call list_accounts to find all connected account IDs
Call validate_content on the base caption for each platform
Identify which platforms need caption overrides (Twitter, Bluesky, etc.)
Build the platformOverrides map
Call create_post with all account IDs
Check get_post after publishing
Call retry_post if any platform shows failed

Multi-platform example — deeper walkthrough with partial failure and retry
All 9 platforms at a glance — comparison table
Common tasks — individual task recipes