Connect YouTube first
- 01
Open Accounts in 1Post and choose Connect.
- 02
Pick Google.
- 03
Sign in with Google and approve access for the YouTube channel you want to post to.
- 04
Choose the YouTube channel in 1Post. It is ready to pick in the composer.
Then GET /v1/accounts returns the id of the YouTube channel to use in the request.
YouTube posts go into one of the account's playlists; GET /v1/accounts/{id}/targets lists them.
Send a post to YouTube
YouTube refuses a post without media, so upload the file first and put its id in media_ids (POST /v1/media/uploads, or POST /v1/media to fetch a public address). Then schedule the post.
curl https://api.get1post.com/v1/posts \
-H "Authorization: Bearer $ONEPOST_API_KEY" \
-H "Idempotency-Key: youtube-first-post" \
-d '{"accounts":["ACCOUNT_ID"],"parts":[{"text":"How we plan a month of posts in one hour.","media_ids":["MEDIA_ID"]}],"schedule_at":"2026-11-02T15:00:00Z"}'The reply is 202 with the post (status scheduled) and one destination for YouTube, which moves from queued to published or failed.
What you can send to YouTube
- Video
- Shorts
- Title, description and tags
- Privacy, made for kids and synthetic media labels
- Thumbnail
- Playlists
What YouTube publishes
- The tag list can hold 500 characters in total. Commas between tags count, and a tag with a space counts two extra characters for the quotation marks YouTube adds.
YouTube rules the request is checked against
| Rule | What 1Post checks |
|---|---|
| Text limit | 5,000 characters, counted by code points |
| Title limit | 100 characters |
| Description limit | 5,000 characters |
| Tags | 500 characters in total |
| Media accepted | Video |
| Videos per post | 1 |
| Threads | No |
| First comment | No |
| Posts per day, per connected account (1Post) | 10 |
The same table with sources is on the YouTube specs page.
YouTube options in the request
- Media is required: YouTube refuses a post without it. Upload the file first (POST /v1/media/uploads, or POST /v1/media to fetch a public address) and list its id in the media_ids of a part.
Check the post before it is queued
Add "dry_run": true to test a post: nothing is kept, a valid one answers 200 and a broken one answers 422 naming the rule.
{
"error": {
"code": "invalid_for_platform",
"message": "youtube refuses this post: YouTube counts 5,032 of 5,000 characters in part 1. (text_too_long).",
"fix": "Fix the rule named in the message and send the post again.",
"retryable": false,
"request_id": "REQUEST_ID"
}
}An assistant connected to the MCP server sends the same fields to create_post; set one up.