pinterest.cover_image.mime_allowed - letmepost.dev

What it checks

The reachability probe of pinterest.coverImageUrl records the response’s Content-Type header. If it isn’t one of the allowlisted image mimes, preflight fails before the video upload runs. Allowed: image/jpeg, image/png, image/webp.

Why

Pinterest’s pin endpoint expects the cover URL to serve a real image — HEIC, GIF, AVIF, or application/octet-stream from a misconfigured CDN all surface upstream as opaque pin failures. Preflight maps that to a clear remediation.

Failure response

{
  "error": {
    "code": "preflight_failed",
    "rule": "pinterest.cover_image.mime_allowed",
    "platform": "pinterest",
    "message": "Cover image mime type 'image/heic' is not allowed on Pinterest.",
    "remediation": "Use one of: image/jpeg, image/png, image/webp."
  }
}

Remediation

Re-encode the cover image to JPEG:

sips -s format jpeg cover.heic --out cover.jpg
# or
ffmpeg -i cover.heic cover.jpg

Then host the JPEG (or PNG / WebP) URL.