Publish to Instagram, Facebook, TikTok, YouTube, X or Bluesky. This posts publicly unless the platform's privacy setting says otherwise, so confirm the content with the user first. `post` is exactly the JSON body of POST /api/v1/posts: Instagram takes image, legacy image-only images, reel, story, or mixed image/video carousel. Instagram video can be base64 MP4 or {"url": "https://..."}; prefer a URL for large video. Image altText and coordinate userTags, video username-only userTags, Reel shareToFeed, collaborators, and isAiGenerated are supported where Instagram allows them; hashtags go in caption. Instagram waits for processing and returns only after publication; Stories expire after 24 hours and may have no permalink. Facebook takes image, images, reel or video (base64); TikTok takes video (prefer {"url": "https://..."} over base64) or photos, with music_usage_confirmed: true. Call get_tiktok_creator_info before a TikTok post. TikTok videos publish publicly (privacy_level PUBLIC_TO_EVERYONE or omitted); any other video privacy_level is refused. Photos take any level from get_tiktok_creator_info. post_mode MEDIA_UPLOAD sends a draft to the creator's TikTok inbox instead of publishing. YouTube takes video (prefer {"url": "https://..."}), title, privacy_status (public, unlisted or private) and made_for_kids, all required; ask the user for privacy_status and made_for_kids rather than choosing them. publish_at schedules a private video to go public. Until Adeli passes YouTube's API audit, YouTube keeps every upload private: the result says so with privacyRestricted. X takes text (280 characters, a link counts as 23) and media: up to 4 images, or 1 GIF, or 1 video, as base64 or a video {"url"}; thread is a list of further posts, each a reply to the one before. Every X post is billed at X's price ($0.015, or $0.20 with a link), and a thread that fails part-way returns 207 with the posts that went live. Bluesky takes text (300 characters; links, @mentions and #hashtags become links), and either up to 4 images as base64 with altText each (over 2 MB are resized) or one MP4 video (base64 or {"url"}, up to 100 MB), plus optional langs, and thread like X. Bluesky posting is free. TikTok, Facebook and YouTube video publish asynchronously: poll get_tiktok_post_status, get_facebook_post_status or get_youtube_post_status with the returned publishId. Multipart uploads are REST-only.