n8n

1. Create Header Auth credentials in n8n with Authorization=Bearer YOUR_API_KEY.
2. Add an HTTP Request node. POST https://api.post-uno.com/v1/media/upload-url once per file, then a node that PUTs each file to its uploadUrl.
3. Add a last HTTP Request node. POST https://api.post-uno.com/v1/posts with Content-Type JSON.
4. For a carousel, collect the keys into s3Keys. Instagram takes 2 to 10 items. X takes up to 4.
5. Store the jobId you get back and poll https://api.post-uno.com/v1/posts/JOB_ID to see each platform.

{
  "profileId": "={{ $json.profileId }}",
  "s3Keys": ["={{ $json.key1 }}", "={{ $json.key2 }}"],
  "postType": "carousel",
  "caption": "={{ $json.caption }}",
  "platforms": ["instagram", "x"]
}

profileId is a UUID your API key owns. Copy it from profile_id on any account GET /v1/accounts returns. A profile that is not yours, missing, or not a UUID all come back as 404 { "error": "Profile not found" }.