ChatGPT MCP: make OG images and screenshots in a ChatGPT chat

ChatGPT can make Open Graph images and website screenshots with your templates once Shareglint is added as a custom MCP server: on chatgpt.com you open Plugins, add a custom MCP server with the URL https://shareglint.com/mcp and OAuth authentication, sign in to Shareglint, and then mention the plugin with @ in a chat. ChatGPT calls render_image or take_screenshot and gives you finished image URLs; each render uses one unit of the same quota as the API (100 a month free).

The overview guide explains MCP and covers the other clients. This page is only about ChatGPT.

What ChatGPT can do with the tools

The server exposes render_image, get_image, list_templates, get_template, create_signed_url, get_usage, generate_template, take_screenshot, auto_og_url, create_batch, get_batch. In a chat that means:

• Social cards from a list. Paste five post titles and ask for a blog-og card each. ChatGPT calls render_image five times and returns a table of URLs.
• One design, every platform. sizes: ["og", "square", "portrait", "story"] renders the same card for link previews, an Instagram post, a portrait post and a story in one call. The sizes available: og 1200×630, square 1080×1080, portrait 1080×1350, story 1080×1920, pinterest 1000×1500, youtube 1280×720.
• Product cards. "Make a product-og card for each of these three products with name, tagline and price" — the template's fields come from list_templates.
• Screenshots of public pages. "Screenshot https://example.com on a Pixel 8, full page, ads and cookie banners removed."
• Meta tags. create_signed_url returns a URL and a ready <meta property="og:image"> tag to paste into a CMS.
• Bulk. A Google Sheet link and "one card per row" becomes create_batch; get_batch reports progress and the ZIP link.

Add the server

OpenAI documents the flow in Add custom MCP server; availability by plan is in OpenAI's help article on custom MCP servers. It works on ChatGPT on the web, and workspace permissions apply — in a managed workspace an admin may have to allow it.

1. Go to ChatGPT Plugins, select the + button, then Add custom MCP server.
2. Name it Shareglint and, optionally, describe it ("Renders social images from templates and takes website screenshots").
3. Under Connection, enter the Server URL https://shareglint.com/mcp.
4. Choose OAuth authentication. Leave client credentials empty: Shareglint supports dynamic client registration, so ChatGPT registers itself. (Shareglint does not advertise Client ID Metadata Documents, the other option OpenAI describes.)
5. Review the risk warning, select I understand and want to continue, then Create as a plugin.
6. Install the plugin from your personal plugins (or the workspace where you created it) and complete the Shareglint sign-in and consent screen.

The consent screen names the app and the address it returns to (chatgpt.com). If you belong to several Shareglint workspaces, pick the one whose templates and quota ChatGPT should use. The connection appears under Connected apps in your Shareglint account settings, where Disconnect signs it out at once. Tokens last a day and refresh without asking you again.

Using it in a chat

Type @ in the prompt box and select the Shareglint plugin. OpenAI's guide recommends being explicit when several tools could fit, and it matters here because ChatGPT also has its own image generation. A prompt that names the plugin and the tool, and rules out the alternative, is called reliably:

Use the Shareglint plugin's render_image tool with the blog-og template. Do not generate an image yourself.

Confirmations. ChatGPT asks before running any tool that is not marked read-only. On this server list_templates, get_template, get_image, get_batch, get_usage and create_signed_url are read-only and run straight away; render_image, take_screenshot, create_batch and generate_template spend quota, so ChatGPT shows their input and waits for you. Read the JSON before approving — it is where you spot a truncated title or the wrong template. You can let ChatGPT remember an approval for the rest of the conversation; a new conversation asks again.

Worked example: a week of social cards in one chat

You run a newsletter and want cards for this week's four posts, in link-preview and Instagram sizes, plus a screenshot of the archive page.

(Plugin Shareglint selected with @.) First call list_templates and tell me the fields of blog-og. Then, for each post below, call render_image with template blog-og, sizes og and square, eyebrow "Weekly", site "northwind.dev", accent "#6366f1", author "Maya Chen", and the title exactly as written. Do not generate images yourself. Finally take a screenshot of https://northwind.dev/archive with take_screenshot, full_page true, block_cookie_banners true. Reply with a table: post, og URL, square URL.

1. Why we moved to Postgres
2. Ten things that ruin your sleep
3. The cost of a cold start
4. Shipping on Fridays, revisited

How it plays out:

1. list_templates runs without a prompt and returns the fields: title, eyebrow, author, site, date, reading_time, photo, accent, theme.
2. ChatGPT proposes the first render_image call. You check the payload — "template": "blog-og", "sizes": ["og", "square"], "modifications": {"title": "Why we moved to Postgres", …} — and approve, choosing to remember the approval for this conversation so the other three run without asking.
3. Each call returns two renders with their URLs: the 1200×630 card and the 1080×1080 square.
4. take_screenshot asks for its own approval and returns the archive page as a PNG.

The cost: eight renders for the cards and 2 for the full-page screenshot. Asking again for the same title with the same fields reuses the existing image and uses nothing, so regenerating the table later is free.

Want the cards to look like your brand rather than the stock template? Attach a screenshot of your current card and ask for generate_template (paid plans): it returns HTML, CSS, fields and a free preview, and saves only when you say so.

Troubleshooting

The plugin is missing from the @ menu. It is created but not installed. Open Plugins, find it under your personal plugins (or the workspace you created it in) and install it.

"Add custom MCP server" is not there. Your plan or workspace does not allow custom MCP servers, or it is ChatGPT outside the web app. In a Business or Enterprise workspace, ask an admin; workspace restrictions such as Lockdown also apply.

ChatGPT draws an image instead of calling the tool. Name the plugin and the tool and add "do not generate an image yourself", as above. ChatGPT's own images will not have your template's layout.

New tools or changed descriptions do not show up. ChatGPT keeps the tool list it scanned. Open the app's details page in settings and refresh it; the same page lets you switch individual tools off.

Sign-in loops or fails. Remove the plugin and add it again with OAuth and no static credentials, then finish the consent screen in the same window. Check that you signed in to the Shareglint account you meant to.

quota_exceeded. The month's renders are used up; get_usage shows the numbers. Nothing is charged past the quota — see pricing.

A screenshot fails. Only public http(s) pages can be captured. A page behind a login, localhost or a private address is refused, and a failed screenshot returns its unit.

API key needed for something else. ChatGPT never needs one. For scripts and automations, create a key in the dashboard and use the HTTP API — or no-code tools such as n8n and Make.