Hermoso is a marketing MCP server: 301 tools over one OAuth’d endpoint that let an agent research the ads already running in a market, generate finished image and video ads, publish them, and build the paid campaigns behind them. ChatGPT reaches all of it through one connection. This page is about one slice of that — what ChatGPT can actually do on YouTube, and what YouTube will not let it do.
Connect Hermoso to ChatGPT
- Copy the connector URL.
https://app.hermoso.ai/mcp - ChatGPT → Settings → Connectors → Add connector. Name it Hermoso and paste the URL. Connectors may need developer mode switched on once, under Settings → Connectors → Advanced.
- Connect and approve. Sign in with your Hermoso account when the consent page opens — no key to paste.
- Ask ChatGPT for something. “Pull my three closest competitors’ longest-running ads and remix the best hook into a 9:16 video,” or “post this render to the channel.” The agent picks the tools; you approve the spend.
If the connector option is not visible, that is the developer-mode toggle rather than anything on our side; Hermoso’s endpoint is the same streamable-HTTP URL every other client uses.
Then connect YouTube itself, once, under Settings → Connectors in Hermoso. That is an OAuth consent screen, so it is the one step that needs a browser — everything after it is a tool call.
The YouTube tools ChatGPT gets
post_to_youtube— uploads a finished video with a title, a description of up to 5,000 characters, up to 30 tags, and a privacy setting.schedule_post— queues the upload — with the description and tags carried through, which is not something to take for granted.set_youtube_thumbnail— puts a designed thumbnail on the upload. It is the single biggest lever on click-through, and YouTube otherwise picks a frame more or less at random.make_thumbnail— generates that thumbnail in the first place.update_youtube_video / list_youtube_videos— edit an upload’s metadata, or list your own uploads — including unlisted and private ones a public search cannot see.youtube_video_insights / youtube_channel— views, watch time, average view percentage and subscribers gained.list_youtube_comments / reply_to_youtube_comment— read and answer comments as the channel.
The unit really is a video: post_to_youtube takes a videoUrl and there is no image path at all. Two smaller gates worth knowing before an automated upload: a Google project that has not been verified has videos.insert locked to private regardless of what you ask for, and custom thumbnails need a phone-verified channel.
YouTube limits worth knowing before you automate anything
| Text | A YouTube title is capped at 100 characters — and a scheduled item’s text becomes the title. The description is a separate field of up to 5,000 characters, carrying up to 30 tags. It is enforced when the post is created or queued — refused while you are still there to fix it, rather than silently cut on the way out. |
|---|---|
| Visibility | Public, unlisted or private. There is no Studio draft — “YouTube’s API can upload as public, unlisted or private, but it cannot create a Studio draft”, so unlisted is the closest thing to a review state, and it is what an immediate post defaults to so an ad-ready upload is not accidentally public. |
| Carousel | Refused, by name. “YouTube’s unit is a video, not a set of stills. Turn the slides into a video (Hermoso can stitch them) and post that instead, or drop YouTube from this post.” That is not a limitation Hermoso invented to avoid work — it is what YouTube is — and the refusal comes at enqueue, with the way forward attached, rather than as a silently posted first slide. |
| Which account | None — YouTube publishes to the connected channel. |
Try it in ChatGPT
Ask for it in ordinary language — these are sentences, not a DSL:
“Take this film, write a title under 100 characters and a full description with our link, pick ten tags, generate three thumbnail options, and upload it unlisted.”
That walks make_thumbnail → post_to_youtube → set_youtube_thumbnail → youtube_video_insights. Tool calls run in the chat and you approve them there, so nothing publishes without you seeing the caption first.
ChatGPT on YouTube: the part that bites
The description is where most automated YouTube uploads go wrong — the caption becomes the title, which is capped at 100 characters, and the description is a separate 5,000-character field that carries the links and the CTA. Ask for both explicitly. Thumbnails need a phone-verified channel, and an unverified Google project has uploads locked to private no matter what privacy you request.
ChatGPT is the only client that renders Hermoso’s inline widgets; anywhere else the same tools return plain structured results.
Research YouTube before you post
search_youtube searches the public YouTube index — which is a different question from “what have I uploaded”, and list_youtube_videos is the tool for that one. For a competitor’s film, analyze_video returns the voiceover, the on-screen text and the beat list with timestamps, which is what you actually want before rebuilding a hook.
The paid half
Hermoso’s Google Ads tools build search, display and Performance Max campaigns — the whole tree in one atomic operation, read back from Google before your agent narrates it — plus Keyword Planner volumes, conversion actions, and sitelinks and callouts created and attached. There is no YouTube video-campaign builder, and it would be wrong to imply one; a YouTube video asset can be uploaded and attached, but the campaign types Hermoso creates are search, display and Performance Max.
What ChatGPT cannot do on its own
An agent with a budget is only useful if the blast radius is bounded, so the fence is in the server rather than in a prompt. Every ad campaign, ad set, ad group and ad is created paused, and the status switches that arm real money refuse to run without an explicit confirmation flag. Every render is quoted first — hermoso_capabilities publishes each model’s exact credit cost before anything spends — and credits are reserved before the first provider call and settled at the exact cost afterwards, so a failed dispatch refunds rather than leaving you billed for nothing. Deletes are confirm-gated too, and every campaign tree is read back from the ad platform before your agent tells you what it built.
One step is deliberately not headless: linking an account is an OAuth consent screen, so you connect the channel once in a browser. Everything after that is a tool call.
The rest of the matrix
From ChatGPT, post to: Facebook · Instagram · Threads · TikTok · X · LinkedIn · Pinterest — or see everything ChatGPT can publish to.
Post to YouTube from: Claude · Claude Code · Cursor · Codex · Cline · OpenClaw · Hermes
Frequently asked questions
Can ChatGPT post to YouTube?
Yes, through Hermoso's MCP server. In ChatGPT, add https://app.hermoso.ai/mcp as a custom connector and approve it with your Hermoso account — there is no key to paste. ChatGPT then has 301 tools, including the ones that publish to YouTube — and the ones that research the ads already running in your market and render the creative in the first place.
How do I connect YouTube to ChatGPT?
Two steps, once each. In ChatGPT, add https://app.hermoso.ai/mcp as a custom connector and approve it with your Hermoso account — there is no key to paste. Then connect YouTube inside Hermoso under Settings → Connectors, which is an OAuth consent screen in a browser. After that ChatGPT publishes to YouTube as an ordinary tool call.
Can ChatGPT post a carousel to YouTube?
No, and the refusal says why rather than saying "unsupported": YouTube’s unit is a video, not a set of stills. Hermoso can stitch the slides into a video and post that instead. ChatGPT calls the same publish tool either way, and a channel that cannot carry a carousel is refused with the real reason attached.
Can ChatGPT run YouTube ads as well as posting?
Hermoso builds Google Ads search, display and Performance Max campaigns, with Keyword Planner volumes and conversion actions. There is no YouTube video-campaign builder, and we do not imply one.
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