MostlyRender

MCP server (AI agents)

Let an AI agent — Claude Desktop, Claude Code, Cursor, or any Model Context Protocol client — render images and PDFs from your templates, and screenshot live URLs, as tool calls. It’s the same REST API you’d call yourself, exposed as agent tools.

There’s one Mostly Tiny MCP server (mostlytiny-mcp). You can run it two ways — scoped to just MostlyRender, or signed in to your whole Mostly Tiny account. Both expose the same MostlyRender tools; pick by how much of the toolkit you want.

Run the server with a single MostlyRender key and it exposes only the render tools — a small, focused tool surface, which is what agents pick from most reliably. Create a key in Settings → API keys (mr_live_… or mr_test_…), then:

Claude Code:

bash
claude mcp add mostly-tiny --env MOSTLYRENDER_API_KEY=mr_live_xxx -- npx -y mostlytiny-mcp

Claude Desktop / Cursor (claude_desktop_config.json · .cursor/mcp.json):

json
{
  "mcpServers": {
    "mostly-tiny": {
      "command": "npx",
      "args": ["-y", "mostlytiny-mcp"],
      "env": { "MOSTLYRENDER_API_KEY": "mr_live_xxx" }
    }
  }
}

Use an mr_test_… key while wiring up — test renders don’t touch your live usage.

# The whole toolkit — hosted, sign-in (no key)

Using more than one product? Add the hosted server by URL and sign in with your Mostly Tiny account in the browser (OAuth 2.1 — no API key to manage). You get every live product’s tools at once: render an image and make a QR code, generate a privacy policy, add a map — from one install.

bash
claude mcp add --transport http mostly-tiny https://mcp.mostlytiny.io

Either way, the always-on mostlytiny_catalog tool lets an agent discover the rest of the portfolio (and how to switch a product on) — so you can start with MostlyRender and grow into the toolkit without reinstalling anything.

# MostlyRender tools

Tool What it does
mostlyrender_list_templates List your templates (id, name, size, engine). Call this first — each layer name is a render parameter.
mostlyrender_render Render a template to PNG / JPEG / WebP / PDF → public asset URL. Overrides layers by name.
mostlyrender_render_batch Render many variations of one template in a single call.
mostlyrender_screenshot Capture any public URL as an image or PDF.
mostlyrender_render_by_url Render-on-the-fly via a signed URL (OG images, <img> tags).
mostlyrender_get_render Check an async render’s status and get its result URL.
mostlyrender_get_account Return the connected account’s plan, usage and email.

# A typical agent flow

The agent discovers a template, sees its layers are named title, subtitle and badge, then renders it — no human in the loop:

text
You:   Make a launch image titled "We raised our Series A".
Agent: → mostlyrender_list_templates   → tpl_launch (layers: title, subtitle, badge)
       → mostlyrender_render            { template: "tpl_launch",
                                          modifications: { title: "We raised our Series A",
                                                           badge: "News" } }
       ← https://img.mostlyrender.com/r/rnd_9f3a.png

Because the layer name is the parameter, an agent can introspect a template and fill it correctly with nothing wired up. See Templates as parameters.

# Authentication

The scoped server authenticates with your API key — the same key the REST API and SDKs use; the hosted server uses your signed-in Mostly Tiny account instead. Renders made by an agent are billed exactly like any other render: by usage, never blocked.

Variable Required Default
MOSTLYRENDER_API_KEY yes (scoped mode) —
MOSTLYRENDER_BASE_URL no https://api.mostlyrender.com