Post to X from Cursor

Hermoso is a marketing MCP server: 830+ 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. Cursor reaches all of it through one connection. This page is about one slice of that — what Cursor can actually do on X, and what X will not let it do.

Connect Hermoso to Cursor

1. Install and sign in.

   npm install -g hermoso && hermoso auth login

   Your browser opens once. Nothing to create and nothing to paste: the credential is stored owner-only in ~/.hermoso/config.json. On a machine with no browser, hermoso auth login --token hmk_… takes a key from Settings → Agents & API keys instead.
2. Add it to ~/.cursor/mcp.json (or the project’s .cursor/mcp.json). No key goes in the file, because hermoso mcp reads the sign-in above:

   { "mcpServers": { "hermoso": { "command": "npx", "args": ["-y", "hermoso", "mcp"] } } }

3. Or use the one-click install from the MCP page. That deeplink installs the hosted URL and leaves authentication to Cursor’s own OAuth flow. Both work, they are just different prerequisites.
4. Ask Cursor 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.

The block above runs the published hermoso npm package on your machine, which is why nothing is pasted and why the tool list costs nothing until a tool is called. If you use the deeplink instead, Cursor performs dynamic client registration against our authorization server and you never hold a key either.

Then connect X 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 X tools Cursor gets

• post_to_x — posts text, an image or a video with alt text, a whole thread, a reply, a quote post, or a poll — and can restrict who is allowed to reply.
• post_x_article — publishes a long-form Article. Write it in Markdown and the headings, lists, quotes, links, code blocks and tables all carry across.
• edit_x_post — rewrites a post you have already published, inside the hour X allows.
• schedule_post — queues it on the shared calendar.
• x_post_metrics — the public counts on a post.
• x_post_insights — advertiser-grade numbers — impressions, link clicks, profile visits, video views and completion quartiles — for the last 28 hours only.
• x_post_insights_historical — the same numbers over any date range, up to 25 posts at a time. This is the one for “how did last month go”.
• x_mentions — who is talking about the brand.
• delete_x_post — removes a post.

X is the only connector that costs money per call, and the numbers are published rather than hidden. Meta, TikTok, LinkedIn, YouTube, Threads and Drive cost nothing per request; X charges us, so those calls bill a small number of credits each. A plain post is priced at $0.015 per request and a post containing a link at $0.200 — roughly 13× more. Deletes, reads and the alt-text metadata write each carry their own price, and insights bill per post returned. Link detection deliberately errs toward assuming a link is present, because guessing wrong the other way costs us 13×. The practical consequence: on X, one good post beats five, and your agent is quoted the price before it posts. Length is the posting account’s, not a flat 280. Hermoso reads the account’s own X subscription and sends up to 25,000 characters where Premium allows it, so a long post goes out whole rather than coming back refused, and nothing is ever truncated. That happens to be the cheap shape too: one long post is a single billed X call where the same words split across five posts are five. X Premium also unlocks two things Hermoso publishes for you: a long-form Article, written in Markdown with its headings, lists, quotes, code blocks and tables intact, and an edit to a post you have already published, inside the hour X allows.

X limits worth knowing before you automate anything

Try it in Cursor

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

“Draft an X thread from the release notes in this branch, keep every post under 280 characters, put the link only in the last post, and price it first.”

That walks get_brand → generate_text → post_to_x → x_post_insights_historical. Cursor surfaces each tool call in the composer before it runs, so a publish is a click rather than a side effect.

Cursor on X: the part that bites

The length refusal is a feature in an editor: Hermoso reads what your account is entitled to — 280 characters ordinarily, up to 25,000 with X Premium — and hands back a clean error naming the overage rather than a truncated post, so the fix is a text edit and a retry. Keep the link in one post — a post carrying a link is priced at roughly 13× a plain one, and a five-post thread that links five times costs what it sounds like.

Put the config in the project’s .cursor/mcp.json rather than the home directory when a repo should always run against one brand; hermoso auth login is what pins the workspace otherwise.

Research X before you post

There is no X ad library to search. X research here is your own account: mentions, post metrics and the historical advertiser numbers. Everything else in the research surface — Meta, Google and LinkedIn ad libraries, organic TikTok, Instagram, YouTube, Reddit and Threads — is unaffected.

The paid half

X Ads landed in August 2026, so X is now both halves. The X Ads API is a separate product on a separate host with its own OAuth 1.0a signing, which is why it arrived after the rest — and Hermoso now builds the whole promoted-post tree on it: campaign, line item (X’s name for an ad group), promoted tweet, targeting, budgets, status and reporting. An X ad promotes a post, so the creative is a post — the same one Hermoso publishes organically. The switch that arms real money refuses to run without an explicit confirmation, exactly as on the other ten platforms. One thing to know before you plan a budget: X grants Ads API access per ad account rather than per app, so there is no OAuth button for it: you add Hermoso’s X user to your ad account at business.x.com → Account access, and it appears in list_x_ads_accounts with the permission level X gave it.

What Cursor 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 Cursor, post to: Facebook · Instagram · Threads · TikTok · YouTube · LinkedIn · Pinterest — or see everything Cursor can publish to.

Post to X from: Claude · ChatGPT · Claude Code · Codex · Cline · OpenClaw · Grok Bot · Hermes

Frequently asked questions

Can Cursor post to X?

Yes, through Hermoso's MCP server. Run npm install -g hermoso && hermoso auth login, then point ~/.cursor/mcp.json at npx -y hermoso mcp. The browser sign-in stores the credential, so no key goes in the file. Cursor then has 830+ tools, including the ones that publish to X — and the ones that research the ads already running in your market and render the creative in the first place.

How do I connect X to Cursor?

Two steps, once each. Run npm install -g hermoso && hermoso auth login, then point ~/.cursor/mcp.json at npx -y hermoso mcp. The browser sign-in stores the credential, so no key goes in the file. Then connect X inside Hermoso under Settings → Connectors, which is an OAuth consent screen in a browser. After that Cursor publishes to X as an ordinary tool call.

What is the X caption limit when posting from Cursor?

That depends on the account, and Hermoso checks rather than guessing. An ordinary X account is capped at 280 characters; one with X Premium goes up to 25,000. Hermoso reads the subscription from X and sends the post, so a long post goes out whole, and nothing is ever truncated. On a Premium account one long post usually reads better than a thread and costs less, because it is a single billed X call where five parts are five. Premium also unlocks long-form Articles, written in Markdown, and an edit to a post already published inside the hour X allows. Hermoso enforces it when the post is created or queued, so Cursor is told immediately rather than failing later when nobody is watching.

Can Cursor run X ads as well as posting?

Yes, since August 2026. X Ads runs on a separate host with its own OAuth 1.0a signing, and Hermoso builds the whole tree on it — campaign, line item, promoted tweet, targeting, budgets, status and reporting. X grants Ads API access per ad account rather than per app, so there is no OAuth button for it: you add Hermoso’s X user to your ad account at business.x.com → Account access.