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. Hermes reaches all of it through one connection. This page is about one slice of that — what Hermes can actually do on Facebook, and what Facebook will not let it do.
Connect Hermoso to Hermes
- Create an API key. In Hermoso, open Settings → Agents & API keys and press ＋ Create API key. It looks like
hmk_…and carries real spend authority, so treat it like a password. - Add an MCP server pointing at the hosted endpoint with your key:
{ "url": "https://app.hermoso.ai/mcp", "headers": { "Authorization": "Bearer <your key>" } } - Ask Hermes 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.
Hermoso is not affiliated with or endorsed by the makers of Hermes, and this is not a bespoke integration — it is the same generic HTTP MCP block any conforming client takes. We would rather say that than imply a partnership that does not exist.
Then connect Facebook 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 Facebook tools Hermes gets
post_to_meta— publishes to the Page — text, an image, a video, or a multi-photo post — and takespageIdso it never has to guess which Page.schedule_post— queues the same post for a time you choose, on one calendar shared with every other channel.list_meta_pages— lists the Pages the account has connected, with their ids.manage_meta_post— edits the copy of a published post, or deletes it.list_meta_comments / reply_to_meta_comment / moderate_meta_comment— reads the comments under a post, replies as the Page, and hides or deletes what should not be there.meta_page_insights / meta_post_insights— Page-level and per-post reach, impressions and engagement.upload_meta_asset— puts a finished render into the ad account’s asset library.
Facebook is also the one channel with native remote scheduling — post_to_meta takes a scheduleAt between ten minutes and thirty days out and hands the timing to Meta itself. Instagram and Threads have no such thing in Meta’s API, and passing it for them is refused rather than quietly posted immediately.
Facebook limits worth knowing before you automate anything
| Text | A Facebook post can run to 63,206 characters, which is effectively no limit. 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 or draft. A draft is a genuinely unpublished Page post, which is the useful one for review: it exists in Meta Business Suite and nobody outside can see it. There is no unlisted and no private — “a Facebook Page post is either published or held as an unpublished draft”. |
| Carousel | 2 slides and up, photos only. Meta publishes no maximum for attached_media that we could source, so Hermoso does not invent one and attribute it to Facebook — the only bound is ours, at 30 slides, and the refusal says whose it is: “Facebook publishes no documented maximum for attached_media, so this bound is ours, not theirs.” Video cannot ride in a Facebook photo carousel; that is a different edge on Meta’s API and Hermoso refuses rather than silently dropping the clip. |
| Which account | pageId. It matters the moment a brand connects more than one Page: the publish path refuses by name instead of picking one for you, and a schedule that could not carry the answer would turn that refusal into a failure hours later with nobody watching. |
Try it in Hermes
Ask for it in ordinary language — these are sentences, not a DSL:
“Render this week's image ad from the brand profile and hold it on the Page as an unpublished draft with the caption written.”
That walks find_competitors → search_meta_ads → plan_ad → render_ad → list_meta_pages → post_to_meta. Approval behaviour is yours to configure. Hermoso’s own guarantees do not depend on it: campaigns are born paused, spend switches are confirm-gated, and no generation call runs without a verified account behind it.
Hermes on Facebook: the part that bites
Facebook is the gentlest channel to automate because the draft is genuine — the post exists in Business Suite and nobody outside can see it — and a published post can still be edited or deleted with manage_meta_post. Pin the pageId: with more than one connected Page the publish path refuses to guess rather than picking wrong.
For unattended runs the hermoso CLI with --json is easier to assert on than a tool manifest, and much cheaper in context.
Research Facebook before you post
The Meta Ad Library is the richest public creative archive there is, and search_meta_ads reads it — by keyword or by page — covering both Facebook and Instagram placements. pull_competitor_ads and competitor_teardown build on it, and find_competitors works out who to point them at.
The paid half
Facebook is the deepest paid surface Hermoso has. create_meta_campaign, create_meta_adset and create_meta_ad build the whole tree with real targeting — geography down to a city radius, interests, behaviours, custom audiences and lookalikes, placements, dayparting, bid and cost caps. Everything is created PAUSED with no caller override, and the summary your agent reports is built from a read-back of what Meta actually stored, never from what was requested. Before a budget is committed, preview_meta_ad renders the real ad per placement as a link you can look at and estimate_meta_reach says how many people the targeting actually reaches. One warning that saves money: an ad set created with no locations defaults to the United States only, and the read-back says so loudly.
What Hermes 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 Hermes, post to: Instagram · Threads · TikTok · YouTube · X · LinkedIn · Pinterest — or see everything Hermes can publish to.
Post to Facebook from: Claude · ChatGPT · Claude Code · Cursor · Codex · Cline · OpenClaw
Frequently asked questions
Can Hermes post to Facebook?
Yes, through Hermoso's MCP server. Create an API key in Hermoso under Settings → Agents & API keys, then add https://app.hermoso.ai/mcp to Hermes with an Authorization: Bearer header. Hermes then has 301 tools, including the ones that publish to Facebook — and the ones that research the ads already running in your market and render the creative in the first place.
How do I connect Facebook to Hermes?
Two steps, once each. Create an API key in Hermoso under Settings → Agents & API keys, then add https://app.hermoso.ai/mcp to Hermes with an Authorization: Bearer header. Then connect Facebook inside Hermoso under Settings → Connectors, which is an OAuth consent screen in a browser. After that Hermes publishes to Facebook as an ordinary tool call.
Does Hermes need my Facebook password?
No. You connect Facebook to Hermoso once through an OAuth consent screen in a browser, and Hermes then reaches it as a tool call. Linking an account is the one step that is not headless; nothing after it needs a password, and no credential is ever handed to the model.
Can Hermes research Facebook before it posts?
Yes. The Meta Ad Library is searchable through search_meta_ads by keyword or by page, and it covers Facebook and Instagram placements together.
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