Post to Bluesky from ChatGPT

ChatGPT can post to Bluesky, read the replies and answer DMs, all as tool calls in one chat. Links get a proper preview card, because Hermoso builds it and Bluesky does not.

Hermoso is a marketing MCP server: 850+ 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 Bluesky, and what Bluesky will not let it do.

Connect Hermoso to ChatGPT

  1. Copy the connector URL. https://app.hermoso.ai/mcp
  2. ChatGPT → Settings → Connectors → Add connector. Name it Hermoso and paste the URL. Connectors may need developer mode switched on once, under Settings → Connectors → Advanced.
  3. Connect and approve. Sign in with your Hermoso account when the consent page opens — no key to paste.
  4. 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 Bluesky itself, once, under Settings → Connectors in Hermoso, with your handle and a Bluesky app password. There is no consent screen: the app password is made in Bluesky’s own settings, and it can be revoked there without touching your real password.

The Bluesky tools ChatGPT gets

  • post_to_bluesky — publishes a post as the connected account: up to 300 characters, with up to four images and alt text, or one MP4 video with optional caption tracks. A link with no media gets a preview card, which Hermoso builds because Bluesky does not fetch one.
  • schedule_post — queues it on the calendar every other channel shares, with the 300-character cap checked when it is queued rather than when it fires.
  • list_bluesky_posts — the account’s own recent posts with their AT-URIs and live counts, marking reposts so someone else’s post is never read as yours.
  • bluesky_post_metrics / bluesky_account — likes, reposts, replies, quotes and bookmarks per post, and followers, following and post count for your account or any public one.
  • list_bluesky_convos / read_bluesky_dm / send_bluesky_dm — read and answer direct messages, including message requests from people the account does not follow.
  • manage_bluesky_convo / react_to_bluesky_dm / mark_bluesky_convo_read — accept a request, mute, lock or leave a conversation, react with one emoji, and clear unread counts.
  • delete_bluesky_post — removes a post, after a first call that deletes nothing and reads back what would go.

Bluesky connects with an app password rather than a sign-in screen: create one in Bluesky’s settings and paste it with the handle under Settings → Connectors. Tick direct-message access when you create it, or the DM tools will tell you the password cannot chat, which is a property of the password and not a broken connection. Two more Bluesky rules Hermoso checks before sending: a video needs a confirmed email on the Bluesky account, and a link card and an image cannot share a post. Publishing costs no credits, because Bluesky charges nothing per call.

Bluesky limits worth knowing before you automate anything

TextA Bluesky post is capped at 300 characters and, separately, at 3,000 bytes, so an emoji-heavy post can be under 300 characters and still too long. 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.
VisibilityPublic only. A Bluesky post is a public record on the AT Protocol, and there is no unlisted, private or draft form of one. The review happens before the call, never after it.
Carousel2 to 4 images, images only. Four is Bluesky’s own number, from the AT Protocol lexicon for an image embed, and a fifth is refused rather than dropped. A video is a different embed that carries exactly one clip, and a post has a single embed, so a Bluesky post is images, one video or a link card: one of the three.
Which accountNone, unless the brand has connected more than one Bluesky account. Then account names which, and several with none named is refused by name rather than guessed.

Try it in ChatGPT

Ask for it in ordinary language — these are sentences, not a DSL:

“Share our launch blog post on Bluesky with a short hook under 300 characters and a link card, then list the DM requests we have not answered.”

That walks get_brandgenerate_imagepost_to_blueskybluesky_post_metrics. Tool calls run in the chat and you approve them there, so nothing publishes without you seeing the caption first.

ChatGPT on Bluesky: the part that bites

Bluesky does not fetch link previews. Paste a bare URL and it shows as plain blue text, so Hermoso fetches the page and builds the card itself whenever a post has a link and no media. The catch is that a post carries one embed: a link card, images or a video, never two. If ChatGPT attaches a render, the card is skipped and the reply says so, while the link stays clickable.

ChatGPT is the only client that renders Hermoso’s inline widgets; anywhere else the same tools return plain structured results.

Research Bluesky before you post

There is no Bluesky ad library and no Bluesky search in Hermoso, so competitor research there comes down to one honest thing: bluesky_account reads any public account’s followers, following and post count, which is enough to size a competitor and chart it week by week. Everything else in the research surface (the Meta, Google and LinkedIn ad libraries, organic TikTok, Instagram, YouTube, Reddit and Threads) is unaffected.

The paid half

There is no Bluesky ads product in Hermoso, and we do not imply one. Bluesky here is organic: publish, schedule, read, reply and measure. The paid tools cover Meta, Google Ads, Microsoft Advertising, Reddit Ads, LinkedIn, Pinterest, X Ads, TikTok Ads, Snapchat Ads, ChatGPT Ads and Apple Search Ads.

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 yours: creating the Bluesky app password and connecting it once. Everything after that is a tool call.

The rest of the matrix

From ChatGPT, post to: Facebook · Instagram · Threads · TikTok · YouTube · X · LinkedIn · Pinterest · Telegram — or see everything ChatGPT can publish to.

Post to Bluesky from: Claude · Claude Code · Cursor · Codex · Cline · OpenClaw · Grok Bot · Hermes · Gemini CLI · Perplexity · Le Chat

Frequently asked questions

Can ChatGPT post to Bluesky?

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 850+ tools, including the ones that publish to Bluesky — and the ones that research the ads already running in your market and render the creative in the first place.

How do I connect Bluesky 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 create an app password in Bluesky's settings (tick direct-message access if you want the DM tools) and paste it with your handle under Settings → Connectors in Hermoso. After that ChatGPT publishes to Bluesky as an ordinary tool call.

Can ChatGPT post a carousel to Bluesky?

Up to a point: 2 to 4 images, images only, which is the limit in Bluesky’s own lexicon. A video goes up as its own post, one clip per post, because a Bluesky post carries a single embed. 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 Bluesky ads as well as posting?

No. There is no Bluesky ads product in Hermoso. Bluesky here is organic: publish, schedule, read engagement, and handle replies and DMs.

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