How to Schedule Threads Posts via API
Publish text posts, images, and videos to Threads using the PostFast API. Schedule content programmatically with full media support.
Threads is Meta's text-based conversation app that competes with X (Twitter). Using the PostFast API, you can schedule posts to Threads including text-only posts, single images or videos, and carousels of images, videos or both.
Threads posts support up to 500 characters of text, and you can attach up to 10 images and videos, mixed in one carousel if you like. The platform integrates with Instagram, so your Threads account is linked to your Instagram profile.
Key capabilities when scheduling Threads posts via API include text posts (up to 500 characters), image and video posts (a single item, or a carousel of up to 10), and cross-posting to Instagram if desired. You can also give each post its topic with the threadsTopicTag control, one topic per post.
API Parameters
| Parameter | Type | Description |
|---|---|---|
threadsTopicTag | string | The post's topic on Threads: one topic per post, 1-50 characters, with no "." or "&". It shows as the post's topic in Threads, and if the text also contains a #hashtag, the topic wins and the hashtag stays plain text. Like every control, it applies to every post in the request. |
Code Example
const response = await fetch('https://api.postfa.st/social-posts', {
method: 'POST',
headers: {
'pf-api-key': 'YOUR_API_KEY',
'Content-Type': 'application/json'
},
body: JSON.stringify({
"posts": [
{
"content": "Just shipped a new feature! Building in public is the way. 🚀\n\nWhat are you working on today?",
"mediaItems": [
{
"key": "image/a1b2c3d4-e5f6-7890-1234-567890abcdef.jpg",
"type": "IMAGE",
"sortOrder": 0
}
],
"scheduledAt": "2025-01-31T10:00:00.000Z",
"socialMediaId": "99012833-a6df-75b8-e150-889099883005"
}
],
"controls": {
"threadsTopicTag": "Building in public"
}
})
});
const data = await response.json();
Did You Know?
Tips
Keep posts concise - Threads users expect quick, conversational content
Use line breaks to improve readability for longer posts
Include a question to encourage replies and boost engagement
Schedule during peak hours (typically 9 AM - 12 PM and 7 PM - 9 PM)
Schedule to Threads, Instagram, and more from one API
Common Pitfalls
More than 10 items will cause an error. Split larger sets into separate posts.
URLs count toward your 500 character limit. Long URLs can consume significant space.
Unlike X, Threads does not support editing posts after publishing. Double-check content before scheduling.
Frequently Asked Questions
What media types does Threads support?
Threads supports images (JPEG, PNG) and videos (MP4). A post can carry a single image or video, or a carousel of up to 10 items, and a carousel can mix images and videos.
Can I cross-post to Instagram and Threads simultaneously?
Yes, you can schedule separate posts to both platforms using the same API call by including multiple posts with different socialMediaId values.
Does Threads support hashtags?
Threads gives each post one topic instead of hashtags. Set it with the threadsTopicTag control and it shows as the post's topic in Threads. If the text also contains a #hashtag, the topic you set wins and the hashtag stays plain text.