Threads supports text, image, carousel, and video posts. One Threads account per workspace.
Connect
curl -X POST "https://backend.postsiva.com/unified/oauth/url" \
-H "Content-Type: application/json" \
-H "X-API-Key: psk_live_YOUR_KEY" \
-d '{"platform": ["threads"]}'
Post types
| Type | Endpoint | Text limit |
|---|
| Text | POST /unified/post/text | 500 characters |
| Image | POST /unified/post/image | 500 chars (caption) |
| Carousel | POST /unified/post/carousel | 2,200 chars (caption) |
| Video | POST /unified/post/video | 2,200 chars (caption) |
Text posts are limited to 500 characters. Image, carousel, and video captions allow up to 2,200 characters.
Text post
curl -X POST "https://backend.postsiva.com/unified/post/text" \
-H "Content-Type: application/json" \
-H "X-API-Key: psk_live_YOUR_KEY" \
-d '{
"platforms": ["threads"],
"default_text": "Quick thought for Threads — keep it under 500 chars."
}'
threads.threads_text to override default_text when posting to multiple platforms:
{
"platforms": ["threads", "linkedin"],
"default_text": "Longer LinkedIn version with full context and details...",
"threads": {
"threads_text": "Short Threads version."
}
}
Image posts
Provide default_image_id or default_image_url (HTTPS). Postsiva auto-uploads URLs and posts with the resolved media ID:
{
"platforms": ["threads"],
"default_text": "Photo caption.",
"default_image_url": "https://cdn.example.com/photo.jpg"
}
POST /media/upload and pass default_image_id.
Character validation
Text posts exceeding 500 characters return 422:
{
"detail": "Max text character limit for threads is 500. Received 520 characters in threads_text/default_text."
}
{
"platforms": ["threads", "bluesky", "linkedin"],
"default_text": "Cross-posted update.",
"threads": {
"threads_text": "Threads: short take."
},
"linkedin": {
"post_to_personal": true
}
}
Scheduling and drafts
{
"platforms": ["threads"],
"default_text": "Scheduled thread.",
"scheduled_time": "2026-07-12T18:00:00Z"
}
Common errors
| Error | Cause | Fix |
|---|
NOT_CONNECTED | Threads not linked | Complete Meta OAuth |
422 text limit | Over 500 chars on text post | Shorten or use image post for longer caption |
| Missing media | No default_image_id or default_image_url | Upload via /media/upload or pass HTTPS URL |