Optional replacement caption. At least one field in the body is required;
empty payloads are rejected with 422 invalid_payload.
Target-specific limit. Hosted Accounts targets cap captions at 500
characters. BYO caps follow the selected platform and media type:
Facebook 63,206; Instagram 2,200; TikTok 2,200 for video captions / 4,000
for photo-post descriptions; LinkedIn 3,000; Pinterest 800; YouTube 5,000
bytes.
Optional TikTok description override. Photo/slideshow posts: max 4,000
UTF-16 runes. For video posts, Genviral keeps this field for
compatibility and uses it as a fallback source when deriving the TikTok
title if title is blank.
Optional Pinterest topic tags (up to 30). Multi-word tags are supported.
Genviral appends these tags to the Pinterest description, so
caption + appended tags must still fit Pinterest’s 800-character
description limit.
Pass null to clear stored Pinterest settings from the post.
tiktok and pinterest updates are mutually exclusive in one request.
Include only the platform-specific object that matches your targeted
accounts. Other platform-specific objects (for example facebook,
instagram, linkedin, or youtube settings) are rejected with
422 invalid_payload.
Not mutable after creation. Partner API treats external_id as the
create-time idempotency key, so PATCH requests that try to change it return
409 external_id_immutable.
Optional TikTok post URL for background music (e.g.,
https://www.tiktok.com/@genviral/video/1234567890). Pass null to remove
existing music without changing media. This field is TikTok-only.
Instagram’s official publishing API does not support music/sound selection
for carousels or Reels, so update requests that include Instagram accounts
with music_url will be rejected.
Caption: enforced against the targeted accounts. Hosted Accounts targets stay at 500 characters. BYO caps follow platform limits: Facebook 63,206; Instagram 2,200; TikTok 2,200 for video captions and 4,000 for photo-post descriptions; LinkedIn 3,000; Pinterest 800; YouTube 5,000 bytes.
Video: MP4/MOV/M4V/AVI, under 100MB. If duration metadata is present, we enforce 15–60 seconds; when duration is missing we proceed with a warning. ~9:16 aspect recommended.
Slideshow: 1–35 images, JPG/JPEG/PNG, each under 5MB. ~9:16 aspect recommended.
Music: TikTok-only. Instagram’s official API does not support music/sound selection for carousel posts or Reels, so requests with music_url are rejected when any Instagram account is selected.
TikTok settings: supported only when all selected accounts are TikTok BYO accounts.
tiktok.post_mode = MEDIA_UPLOAD: supported only for media.type = slideshow (photo posts).
tiktok.video_cover_timestamp_ms: supported for video DIRECT_POST requests.
Pinterest settings: supported only when at least one selected account is Pinterest.
pinterest.tags: up to 30 tags, each 1–100 characters (spaces allowed). Tags are appended to the final Pinterest description, which still must fit 800 characters.
Update responses can include warnings about missing media metadata. They are
informational so you can re-upload media before Hosted Accounts reject it.