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. Le Chat reaches all of it through one connection. This page is about one slice of that — what Le Chat can actually do on Pinterest, and what Pinterest will not let it do.
Connect Hermoso to Le Chat
- Copy the connector URL.
https://app.hermoso.ai/mcp - Le Chat → Intelligence → Connectors → + Add Connector → Custom MCP Connector. Name it Hermoso and paste the URL.
- Press Connect and approve. Le Chat detects Hermoso’s OAuth sign-in with dynamic client registration and opens the consent page. Sign in with your Hermoso account; there is no key to paste.
- Ask Le Chat 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.
Adding a custom connector is an admin action in Le Chat. On the Free, Pro and Student plans the account owner is the admin, so you can add Hermoso yourself, free plan included; on a team plan an admin adds it. The steps are quoted from Mistral’s MCP connector documentation, read on 2026-09-23. Hermoso is not affiliated with or endorsed by Mistral AI.
Then connect Pinterest 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 Pinterest tools Le Chat gets
list_pinterest_boards— the account’s boards, including secret ones, with their ids.create_pinterest_board— makes a new board.post_to_pinterest— creates an image or video Pin on a board you name, with a title, a description, a destination link and alt text.schedule_post— queues the Pin, carryingboardId.list_pinterest_ads_campaigns / pinterest_ads_report— read the paid side.
The limit you need before you plan a Pinterest workflow: this app holds Trial access, and Pinterest refuses Pin creation in production on Trial. Their words, caught on the first real Pin: “Apps with Trial access may not create Pins in production.” Boards and reads do work on Trial — listing boards, creating boards, reading Pins — and Hermoso’s error names the access tier rather than telling you to reconnect, because reconnecting cannot fix it. An upgrade to Standard access is what unblocks Pin creation, and it is pending review. The same tier limits the paid side: on Trial, Pinterest exposes no ad accounts at all.
Pinterest limits worth knowing before you automate anything
| Text | A Pin description is capped at 800 characters and a Pin title at 100. 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, and the control is the board rather than the Pin. A Pin inherits its board’s public or secret state, so “post it somewhere private” is expressed by choosing a secret board — which is why the board is a required argument rather than a default. |
| Carousel | 2 to 5 images, images only. Both bounds come straight from Pinterest’s own v5 OpenAPI (minItems: 2, maxItems: 5), which is the only machine-readable source Pinterest publishes — their developer site is a client-rendered app that returns nothing to a fetch. There is no multi-video source, so a video slide is refused rather than dropped. |
| Which account | boardId, and it is the only identity field refused at enqueue rather than at publish time: “A Pin has to go on a board — pass boardId. Nothing was scheduled: a Pin on the wrong board is a public mistake, so we never choose one for you.” |
Try it in Le Chat
Ask for it in ordinary language — these are sentences, not a DSL:
“List my Pinterest boards, create one for the summer range, and generate five vertical Pin images for it with titles and descriptions.”
That walks list_pinterest_boards → plan_ad → generate_image → post_to_pinterest. Le Chat lets you set each connector function to Always allow or leave it asking. Mistral’s own advice is to pre-authorise read functions and keep write functions on manual approval, and that is the right split here: research and list tools can run freely, anything that publishes, schedules or deletes should ask.
Le Chat on Pinterest: the part that bites
Board listing and creation work on Trial access, so the structure and the creative can be finished today. Pin creation is refused by Pinterest in production for Trial apps. Hermoso’s error names the tier rather than suggesting a reconnect, and a Le Chat conversation that asks again will get the same answer.
Le Chat’s custom connectors do not pick up new tools after you connect; the list is what it loaded at that moment. Hermoso starts a connector on a short list and includes find_tools and call_tool, which reach every other tool by name, so a tool missing from the loaded list is still one request away.
Research Pinterest before you post
There is no Pinterest ad library, so competitor research on Pinterest is not something Hermoso claims. The creative you would run there is well covered by the rest of the studio — make_template_ad and the image models produce the vertical, text-forward stills the surface rewards.
The paid half
Pinterest Ads tools exist — campaign, ad group and an ad that promotes an existing Pin, and archiving rather than deleting, because Pinterest’s ADS API has no delete verb (organic Pins and boards do delete, through delete_pinterest_pin and delete_pinterest_board; it is the paid objects that can only be archived). But the same Trial-access tier that blocks Pin creation exposes no ad accounts, so ad writes are not usable until Standard access lands. That is the honest state, and it is better in a sentence here than discovered on a deadline.
What Le Chat 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 Le Chat, post to: Facebook · Instagram · Threads · TikTok · YouTube · X · LinkedIn · Bluesky · Telegram — or see everything Le Chat can publish to.
Post to Pinterest from: Claude · ChatGPT · Claude Code · Cursor · Codex · Cline · OpenClaw · Grok Bot · Hermes · Gemini CLI · Perplexity
Frequently asked questions
Can Le Chat post to Pinterest?
Yes, through Hermoso's MCP server. In Le Chat, add https://app.hermoso.ai/mcp as a custom connector and approve it with your Hermoso account — there is no key to paste. Le Chat then has 850+ tools, including the ones that publish to Pinterest — and the ones that research the ads already running in your market and render the creative in the first place.
How do I connect Pinterest to Le Chat?
Two steps, once each. In Le Chat, 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 Pinterest inside Hermoso under Settings → Connectors, which is an OAuth consent screen in a browser. After that Le Chat publishes to Pinterest as an ordinary tool call.
Can Le Chat post privately or as a draft to Pinterest?
Visibility on Pinterest lives on the board, not the Pin: a Pin inherits its board’s public or secret state, which is why the board is a required argument rather than a default. Hermoso refuses a visibility Pinterest cannot honour at the moment you ask for it, rather than quietly publishing something weaker.
Can Le Chat run Pinterest ads as well as posting?
The Pinterest Ads tools exist — campaign, ad group, and an ad promoting a Pin — but the same Trial-access tier that blocks Pin creation exposes no ad accounts, so ad writes are not usable until Standard access lands.
Start free — 30 credits at signup and 250+ more to earn, and every feature on every plan. Credits are spent only on AI models and Ad Spy research; posting, scheduling, ads management and analytics are free.
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