Social media post

Social Media Post via PostFast

You have access to PostFast MCP tools for social media scheduling and management.

Setup Check

If any PostFast tool call fails with an authentication/401 error, tell the user:

1. Go to https://app.postfa.st/dashboard, click API in the sidebar, and generate a key
2. Set the POSTFAST_API_KEY environment variable with the key

Posting Workflow

1. List accounts — Call list_accounts to see connected social media accounts. Each account has an id, platform, platformUsername, displayName, and a connectionStatus (CONNECTED or DISABLED) with an optional disabledReason. If connectionStatus is DISABLED, the account won't publish until the user reconnects it — warn the user and don't schedule to it.

2. Prepare media (if needed) — If the user has images or videos to attach:

   • Use upload_media with the local file path — it handles getting a signed URL, uploading, and returning a key and type (IMAGE or VIDEO)
   • Supported formats: JPEG, PNG, GIF, WebP (images), MP4, WebM, MOV (video)
   • Size limits: 10MB images, 250MB video, 60MB documents (PDF/DOC/DOCX/PPT/PPTX)

3. Create posts — Call create_posts with:

   • socialMediaId: account ID from step 1
   • content: the post text/caption
   • scheduledAt: ISO 8601 datetime (required unless status is DRAFT)
   • mediaItems: array of {key, type, sortOrder} from uploaded media
   • status: SCHEDULED (default) or DRAFT
   • firstComment: optional first comment text, posted automatically after publishing (supported on X, Instagram, Facebook, YouTube, Threads, and TikTok — TikTok: max 1,200 chars, requires a Business API connection)
   • controls: platform-specific settings (see below)
   • You can batch up to 15 posts in a single call — great for content calendars
   • Don't schedule to a DISABLED account — the API rejects it with HTTP 400 socialMediaDisconnected. Saving as DRAFT is still allowed. Check connectionStatus from step 1 first.

4. Confirm — Show the user a summary: which accounts, what content, when scheduled.

Platform-Specific Controls

X (Twitter)

• xRetweetUrl: URL of tweet to retweet (ignores content/media)

Instagram

• instagramPublishType: TIMELINE (default), STORY, or REEL
• instagramTrialReelStrategy: MANUAL or SS_PERFORMANCE — publishes a trial reel, shown only to non-followers until it graduates. MANUAL = the user graduates it in the Instagram app; SS_PERFORMANCE = Instagram graduates it automatically if it performs well. Requires instagramPublishType: REEL and can't be combined with instagramCollaborators (both rejected with HTTP 400 at create time). Omit for a normal reel
• instagramPostToGrid: boolean, default true (for Reels)
• instagramCollaborators: array of usernames to invite as collaborators
• instagramIsAiGenerated: boolean, default false — adds Instagram's "AI info" label. Covers images, reels, stories and carousels (on a carousel it labels the whole post, not individual slides). Set at creation only; the label can't be added or removed after publishing

Facebook

• facebookContentType: POST (default), REEL, or STORY
  • POST: up to 10 photos OR 1 video
  • REEL: 1 video only
  • STORY: 1 image OR 1 video
• facebookReelsCollaborators: array of usernames (for Reels)

TikTok

• tiktokPrivacy: deprecated — TikTok videos use the account default privacy (no per-post control) and photos default to public; use tiktokIsDraft for private posts
• tiktokIsDraft: boolean, default false
• tiktokAllowComments: boolean, default true
• tiktokAllowDuet: boolean, default true
• tiktokAllowStitch: boolean, default true
• tiktokBrandOrganic: boolean, default false
• tiktokBrandContent: boolean, default false
• tiktokAutoAddMusic: boolean, default false
• tiktokIsAigc: boolean, default false (declare the post as AI-generated content — videos and photo posts)
• tiktokTitle: title for photo posts (max 90 chars; photo posts only) — when set, the full content becomes the description; without it, content auto-splits on the first newline into title + description
• tiktokMusicSoundId + tiktokMusicSoundName: attach a pre-cleared Commercial Music Library sound to a photo/carousel post — find sounds with list_tiktok_sounds (the list rotates daily). Mutually exclusive with tiktokAutoAddMusic; not applied when tiktokIsDraft is true. Always set the name alongside the id

YouTube

• youtubeTitle: defaults to first 100 chars of content
• youtubePrivacy: PUBLIC (default), PRIVATE, or UNLISTED
• youtubeTags: array of tag strings
• youtubeCategoryId: YouTube category ID
• youtubeIsShort: boolean, default true
• youtubeMadeForKids: boolean, default false (COPPA compliance)
• youtubeContainsSyntheticMedia: boolean, default false — discloses that the video contains realistic altered or synthetic (AI) content. Sent to YouTube only when true; set at creation only
• youtubePlaylistId: playlist ID (use list_youtube_playlists to find it)
• youtubeThumbnailKey: S3 media key for custom video thumbnail (upload via upload_media or get_upload_urls; JPEG/PNG recommended, max 2MB, min 640px wide, 1280x720 ideal; requires phone-verified YouTube channel)

Pinterest

• pinterestBoardId: required — use list_pinterest_boards to get the boardId
• pinterestLink: destination URL when pin is clicked
• Content is parsed as: first line = pin title (max 100 chars), remaining lines = description (max 800 chars)
• Carousel: 2-5 static images (no videos)

Google Business Profile

• gbpLocationId: required — use list_gbp_locations to get the locationId
• gbpTopicType: STANDARD (default), EVENT, or OFFER
• gbpCallToActionType: BOOK, ORDER, LEARN_MORE, SIGN_UP, CALL, or SHOP
• gbpCallToActionUrl: URL for the CTA button (not needed for CALL, ignored for OFFER)
• gbpEventTitle: title for EVENT/OFFER posts (max 58 chars)
• gbpEventStartDate: start date (ISO 8601, required for EVENT/OFFER)
• gbpEventEndDate: end date (ISO 8601, required for EVENT/OFFER)
• gbpOfferCouponCode: coupon code (OFFER only)
• gbpOfferRedeemUrl: redemption URL (OFFER only)
• gbpOfferTerms: terms and conditions (OFFER only)
• Content max: 1,500 chars. Media: up to 5 images or 1 video. Standard posts expire after 6 months; EVENT/OFFER posts expire at end date.

LinkedIn

• linkedinAttachmentKey: S3 key for document attachment (for document posts)
• linkedinAttachmentTitle: display title for the document (default "Document")
• Cannot mix documents with regular image/video media
• Supported document formats: PDF, DOC, DOCX, PPT, PPTX (max 60MB)

Other Actions

• View posts: list_posts — filter by platforms (comma-separated), statuses (DRAFT, SCHEDULED, PUBLISHED, FAILED), from/to dates, with pagination (page, limit up to 50). Failed or missed posts include a lastError with a code — e.g. MISSED_DISCONNECTED (the account was disconnected when the post was due) or MISSED_NOT_PUBLISHED (missed its slot by more than the 2h grace window)
• Post analytics: get_post_analytics — fetch published posts with performance metrics. Requires startDate and endDate (ISO 8601). Optional filters: platforms, socialMediaIds. Returns impressions, reach, likes, comments, shares, totalInteractions, plus an extras object with platform-specific metrics. Supported: Instagram, Facebook, TikTok, Threads, YouTube, LinkedIn (company pages), Pinterest (Business accounts). Pinterest extras include pin_clicks, outbound_clicks, saves_90d, save_rate_90d; video pins also surface mrc_views, views_10s, avg_watch_time, v50_watch_time, video_starts, quartile_95_views. Video posts also include normalized watch-time on latestMetric: avgWatchTimeSeconds, totalWatchTimeSeconds, videoViews (Facebook, Instagram Reels, YouTube, Pinterest, LinkedIn company pages, TikTok); Instagram posts also include saveRate on latestMetric (saves / reach as a percentage, rounded to 2 decimals; feed posts, reels, and carousels), and Instagram Reels additionally include reelsSkipRate (percentage of viewers who skipped the reel in the first 3 seconds, rounded to 2 decimals; may be absent on low-view reels or until metrics refresh); TikTok also exposes total_time_watched, average_time_watched, and full_video_watched_rate in metric.extras. Note: LinkedIn personal accounts are excluded; Pinterest saves are reported as a rolling 90-day window because Pinterest's API does not expose lifetime save totals (all other Pinterest metrics are lifetime); latestMetric is null if metrics haven't been fetched yet; metric values are strings (bigint). Keep date ranges reasonable as there's no pagination.
• Follower history: get_follower_history — daily follower-count snapshots for one account (socialMediaId), plus currentFollowerCount and a signed delta over the range. Optional from/to (ISO 8601); defaults to the last 90 days, capped at 365. Tracking is forward-only — trackingStartedAt marks when recording began, with no data before it; counts are strings (bigint). Coverage: Facebook Pages, Instagram, YouTube, Pinterest, Threads, Bluesky, Telegram, LinkedIn company pages, and TikTok (not X or personal Facebook)
• Delete a post: delete_post with the post ID
• Connect new accounts: generate_connect_link — creates a secure URL to share with clients/collaborators to connect their accounts. Set expiryDays (1-30) and optionally sendEmail with an email address
• Pinterest boards: list_pinterest_boards — get board IDs before creating Pinterest posts
• YouTube playlists: list_youtube_playlists — get playlist IDs for adding videos to playlists
• GBP locations: list_gbp_locations — get location IDs before creating Google Business Profile posts

Tips

• Always confirm schedule time and target accounts with the user before creating posts.
• If list_accounts shows an account as DISABLED, tell the user to reconnect it before scheduling — scheduled posts to disconnected accounts are rejected, and posts already due get marked missed.
• For content calendars, batch multiple posts in one create_posts call (up to 15).
• When posting to Pinterest, always fetch boards first — pinterestBoardId is required.
• When posting to Google Business Profile, always fetch locations first — gbpLocationId is required.
• Use DRAFT status if the user wants to review posts in the PostFast dashboard before they go live.
• The firstComment feature is useful for adding hashtags on Instagram without cluttering the caption.
• For AI-generated media, set the disclosure control for that platform: instagramIsAiGenerated, youtubeContainsSyntheticMedia, or tiktokIsAigc. All three are set at creation time only — there's no way to add or remove the label after publishing, so ask before scheduling. The other platforms expose no AI flag.