Auto Pin a Comment on YouTube Videos With an API or AI Agent

A pinned comment on YouTube is the first thing viewers see under your video, and it’s where links actually get clicked. Doing it by hand means waiting for the upload to go live, writing the comment, then pinning it. With Creator OS you pass firstComment when you upload and the comment is posted and pinned automatically, the moment the video is live (or at the scheduled time). It works from the API, the CLI, and from Claude or ChatGPT through MCP.

  upload + firstComment
        |
        v
  video goes live (now, or at schedule_at)
        |
        v
  comment posted from your channel ---> pinned to the top
  "Free template: https://go.creatoros.ca/...  00:00 intro
   02:14 setup  05:40 results"

Why pin a comment on every video

• Descriptions are hidden. On mobile, most viewers never expand the description. The pinned comment is visible without a tap.
• It’s the best spot for your offer. Free download, newsletter, app link. Track it with a trackable short link to see exactly how many clicks each video drives.
• It sets the conversation. A question in the pinned comment (“Which tool should I test next?”) gets the replies started.
• Shorts too. Shorts don’t have a usable description, so the pinned comment is the only place for a link.

How to do it

From Claude or ChatGPT

With the YouTube MCP server connected, include it in the request:

• “Upload tutorial.mp4, public tomorrow at 10am, and pin a comment with the template link and these chapters.”
• “For every Short I post this week, pin a comment pointing to the full video.”

From the API

POST /v1/posts
{
  "content": "How I automated my socials with Claude",
  "media": ["med_..."],
  "platforms": [{
    "platform": "youtube",
    "account_id": "acc_...",
    "options": {
      "title": "How I Automated My Socials With Claude",
      "visibility": "public",
      "firstComment": "Free setup guide: https://go.creatoros.ca/xyz\n\n00:00 Intro\n02:14 Setup\n05:40 Results"
    }
  }],
  "schedule_at": "2026-10-10T10:00:00",
  "timezone": "America/New_York"
}

Up to 10,000 characters. With an immediate post it goes up right away; with a schedule, at the scheduled time.

What to put in it

1. One link, first line. The thing you most want clicked.
2. Chapters if the video is long. Viewers jump straight to what they need.
3. A question to start replies.

Then let your AI handle the replies: “Every evening, answer new comments on my latest video that ask a question.” See replying to comments with AI.

Comment funnels on YouTube

YouTube doesn’t have DMs, so a classic comment-to-DM funnel isn’t possible. The pattern that works instead: put the resource link in the description and pinned comment, ask people to comment a keyword, and auto-reply to those comments telling them where the link is. Engagement goes up and people find the link.

Other platforms with a first comment

The same firstComment field works on Instagram (feed posts and carousels), Facebook, LinkedIn and Threads (as a first reply). Only YouTube pins it. See post options.

Prefer to watch? The KevBuildsApps YouTube channel walks through builds like this one, start to finish.

Get started

Creator OS plans start at $19.99/month with the API, MCP server and CLI. Sign up, connect YouTube, and every upload gets its pinned comment.