social-post

Social Post (YouTube, Facebook, Mastodon)

Create and schedule posts to YouTube, Facebook Pages, and Mastodon using the your social MCP server. This skill covers platforms that work through standard posting without platform-specific complexity.

Prerequisites

Plans: Free Starter (15 posts/month), Pro, Premium

Getting Started

1. Create account at your-publisher.example/register (free)
2. Connect platforms via OAuth in SocialPublisher Dashboard:
   • YouTube: Google OAuth (requires YouTube channel)
   • Facebook: Facebook OAuth (Pages only, not personal profiles)
   • Mastodon: OAuth (mastodon.social instance)
3. Get API key at your-publisher.example/settings/api
4. Configure MCP in Claude Desktop (~/.claude/claude_desktop_config.json):

{
  "mcpServers": {
    "social-poster": {
      "type": "http",
      "url": "https://mcp.your-publisher.example",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

REST API Fallback

If MCP is unavailable, use the REST API directly:

Base URL: https://api.your-publisher.example/api/v1

Authentication: x-social-poster-key header

# Get connected platforms
curl -X GET "https://api.your-publisher.example/api/v1/platform-connections" \
  -H "x-social-poster-key: sk_your_api_key"

# Create a post
curl -X POST "https://api.your-publisher.example/api/v1/create-post" \
  -H "x-social-poster-key: sk_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "platforms": ["youtube-UCxxx", "facebook-123456", "mastodon-789"],
    "content": "Your post content",
    "scheduledTime": "2026-03-25T10:00:00Z"
  }'

Platform ID Formats:

• YouTube: youtube-{channel_id} (e.g., youtube-UCxxx)
• Facebook: facebook-{page_id} (e.g., facebook-112233445566)
• Mastodon: mastodon-{id} (e.g., mastodon-456)

📖 Docs: docs.your-publisher.example

Plan Limits

Plan	Posts/month	Price
Starter	15	Free
Pro	100/account	$2.99/account/month
Premium	500/account	$9.99/account/month

---

YouTube

Video-only platform - every post requires a video file.

Platform Limits

Feature	Limit
Video title	100 characters
Video description	5,000 characters
Video duration	12 hours
Video size	512 MB (SocialPublisher limit)
Video formats	MP4, MOV, AVI, MKV, WebM

Platform Settings (via REST API)

{
  "platformSettings": {
    "youtube": {
      "privacy": "public",
      "title": "My Video Title"
    }
  }
}

Setting	Values	Default
privacy	"public", "unlisted", "private"	"public"
title	string	Derived from first 70 chars of content

Note: platformSettings is not available via MCP - use REST API for these settings.

YouTube Examples

Upload this tutorial video to YouTube:
"How to Build a REST API in 10 Minutes - Complete guide for beginners"

Upload this as an unlisted video (for internal sharing):
"Internal demo - Q1 dashboard features"

YouTube Restrictions

1. Video required: YouTube does not support text-only or image posts
2. Single video only: One video per post
3. Processing time: Videos take seconds to minutes to process after upload
4. Token refresh: YouTube tokens expire after ~6 months, reconnect if needed

---

Facebook

Pages only - posts go to Facebook Pages, not personal profiles.

Platform Limits

Feature	Limit
Post text	2,200 characters (frontend) / 63,206 (API)
Images	Up to 10 per post
Image size	10 MB
Video duration	45 minutes
Video size	512 MB (SocialPublisher limit)

Multi-Page Support

If you manage multiple Facebook Pages, each gets its own platform ID:

• facebook-112233445566 (Page 1)
• facebook-778899001122 (Page 2)

You can post to multiple pages in a single request.

Facebook Examples

Post this announcement to my Facebook Page:
"We're thrilled to announce our new product launch! Visit our website to learn more."

Post this to both my Facebook Pages:
"Holiday notice: Our offices will be closed on Monday."

Share these event photos on Facebook:
"Highlights from our company retreat! Great team, great memories."

Facebook Restrictions

1. Pages only: Cannot post to personal profiles via API
2. WebP auto-converted: WebP images become JPEG automatically
3. 59-day token: Tokens auto-refresh, but may need reconnection if it fails
4. No mixed media: A post can have images OR video, not both

---

Mastodon

Fediverse platform - posts federate across the decentralized network.

Platform Limits

Feature	Limit
Post text	500 characters
Images	Up to 4 per post
Image size	16 MB
Video size	~99 MB
Image formats	JPEG, PNG, GIF, WebP
Video formats	MP4, WebM, MOV

Mastodon Examples

Post this to Mastodon:
"Hello fediverse! We just shipped a major update to our open-source project. #opensource"

Share this screenshot on Mastodon:
"New feature: dark mode is here! #ui #darkmode"

Mastodon Restrictions

1. mastodon.social only: Currently connects only to mastodon.social instance
2. Public visibility: All posts are public by default
3. No auto-threading: Unlike X/Twitter, Mastodon doesn't split long content
4. 500-char strict: Content over 500 characters will be rejected

---

Available Tools (All Platforms)

create_post

Create a new post on any platform.

Parameters:

• platforms: Array of platform IDs (e.g., ["youtube-UCxxx", "facebook-123", "mastodon-456"])
• content: Post text
• scheduledTime: ISO 8601 datetime (required - for immediate posting, use current time + 1 minute)

get_upload_url

Get presigned URL for media uploads.

Parameters:

• postGroupId: Post ID to attach media to
• fileName: File name
• contentType: MIME type
• type: "image" or "video"

list_posts / update_post / delete_post

Manage scheduled and draft posts.

---

Cross-Platform Posting

Post to multiple platforms at once:

Post this video to YouTube and this text to Facebook and Mastodon:
"Announcing our new feature - watch the demo!"

SocialPublisher handles platform-specific requirements automatically:

• YouTube gets the video with title/description
• Facebook gets the text + video
• Mastodon gets the text (500 char limit applies)

---

Troubleshooting

Platform	Error	Solution
YouTube	"Video required"	Attach a video file
YouTube	"Account disconnected"	Reconnect via dashboard
Facebook	"Page not found"	Verify page connection
Facebook	"Token expired"	Reconnect page in dashboard
Mastodon	"Content too long"	Shorten to under 500 chars
Mastodon	"Too many images"	Reduce to 4 or fewer
All	Rate limit errors	Wait and retry