Guides

Media & images

Upload media once to get an id, then attach it to a post. Each network has its own limits. A media set that isn't valid for one target fails just that target.

Upload

POST the raw bytes with the correct Content-Type. You get back a MediaAsset.

curl -X POST https://api.postlake.dev/v1/media \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: image/jpeg" \
  --data-binary @photo.jpg

{ "id": "med_abc", "url": "https://…", "contentType": "image/jpeg", "size": 208134 }

Supported: JPEG, PNG, WebP images; MP4 video. Video-only networks (YouTube, TikTok) require a video asset.

Attach. Globally or per platform

Put ids in media to attach to every account, or use mediaOverrides to give each platform its own set (a square image for Instagram, a video for TikTok).

{
  "text": "Launch day",
  "media": ["med_abc"],
  "mediaOverrides": { "tiktok": ["med_video"] },
  "accounts": ["acc_ig", "acc_tt"]
}

Per-platform media limits

Platform	Media
Bluesky	Up to 4 images, or 1 video
Threads	Image carousel, or video
Instagram	Image or video (Reels)
TikTok / YouTube	Video only
X, LinkedIn, Facebook	Images and video
Pinterest	Image or video (needs a `boardId`)

These are the practical rules today; call GET /v1/platforms/{platform} for the live, authoritative limits (max count, size, aspect) so you, or an agent, can validate before posting.

Alt text

Provide accessibility alt text per media item through platformOptions / media alt overrides. If a media set is invalid for a target, that target fails with a clear error and the others still publish, see Errors.