How to integrate HTML/CSS to Image MCP with Mastra AI

This guide walks you through connecting HTML/CSS to Image to Mastra AI using the Composio tool router. By the end, you'll have a working HTML/CSS to Image agent that can render html as images, create images from templates, transform images, manage templates, and track usage through natural language commands. This guide will help you understand how to give your Mastra AI agent real control over a HTML/CSS to Image account through Composio's HTML/CSS to Image MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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HTML/CSS to Image

Api Key

HTML/CSS to Image is an API for converting HTML, CSS, URLs, and templates into images and PDFs. Use it to generate clean visual assets, screenshots, and documents without running browser infrastructure.

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Introduction

This guide will help you understand how to give your Mastra AI agent real control over a HTML/CSS to Image account through Composio's HTML/CSS to Image MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

Also integrate HTML/CSS to Image with

OpenAI Agents SDK Claude Agent SDK Claude Code Claude Cowork Codex OpenClaw Hermes CLI Google ADK LangChain Vercel AI SDK LlamaIndex CrewAI

TL;DR

Here's what you'll learn:

Set up your environment so Mastra, OpenAI, and Composio work together
Create a Tool Router session in Composio that exposes HTML/CSS to Image tools
Connect Mastra's MCP client to the Composio generated MCP URL
Fetch HTML/CSS to Image tool definitions and attach them as a toolset
Build a Mastra agent that can reason, call tools, and return structured results
Run an interactive CLI where you can chat with your HTML/CSS to Image agent

What is Mastra AI?

Mastra AI is a TypeScript framework for building AI agents with tool support. It provides a clean API for creating agents that can use external services through MCP.

Key features include:

MCP Client: Built-in support for Model Context Protocol servers
Toolsets: Organize tools into logical groups
Step Callbacks: Monitor and debug agent execution
OpenAI Integration: Works with OpenAI models via @ai-sdk/openai

What is the HTML/CSS to Image MCP server, and what's possible with it?

The HTML/CSS to Image MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your HTML/CSS to Image account. It provides structured and secure access to your image generation, reusable templates, generated files, and usage data, so your agent can create images, render templates, transform files, manage templates, and monitor usage on your behalf.

HTML and webpage rendering: Have your agent turn HTML and CSS or public web pages into hosted images, including protected pages that require request headers.
Batch image creation: Direct your agent to generate up to 25 images at once from HTML, CSS, or web pages using shared or image-specific settings.
Reusable template management: Let the agent create Handlebars templates, list your existing templates, and update them with new HTML, CSS, or render settings.
Image retrieval and transformation: Instruct your agent to download generated images, convert their format, resize them, crop them, or permanently delete files you no longer need.
Account usage tracking: Have your agent review recent hourly, daily, monthly, and billing-period image usage for your connected account.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step09 STEPS

Prerequisites

Before starting, make sure you have:

Node.js 18 or higher
A Composio account with an active API key
An OpenAI API key
Basic familiarity with TypeScript

Getting API Keys for OpenAI and Composio

OpenAI API Key

Go to the OpenAI dashboard and create an API key.
You need credits or a connected billing setup to use the models.
Store the key somewhere safe.

Composio API Key

Log in to the Composio dashboard.
Go to Settings and copy your API key.
This key lets your Mastra agent talk to Composio and reach HTML/CSS to Image through MCP.

Install dependencies

bash

npm install @composio/core @mastra/core @mastra/mcp @ai-sdk/openai dotenv

Install the required packages.

What's happening:

@composio/core is the Composio SDK for creating MCP sessions
@mastra/core provides the Agent class
@mastra/mcp is Mastra's MCP client
@ai-sdk/openai is the model wrapper for OpenAI
dotenv loads environment variables from .env

Set up environment variables

bash

COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_user_id_here
OPENAI_API_KEY=your_openai_api_key_here

Create a .env file in your project root.

What's happening:

COMPOSIO_API_KEY authenticates your requests to Composio
COMPOSIO_USER_ID tells Composio which user this session belongs to
OPENAI_API_KEY lets the Mastra agent call OpenAI models

Import libraries and validate environment

typescript

import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Agent } from "@mastra/core/agent";
import { MCPClient } from "@mastra/mcp";
import { Composio } from "@composio/core";
import * as readline from "readline";

import type { AiMessageType } from "@mastra/core/agent";

const openaiAPIKey = process.env.OPENAI_API_KEY;
const composioAPIKey = process.env.COMPOSIO_API_KEY;
const composioUserID = process.env.COMPOSIO_USER_ID;

if (!openaiAPIKey) throw new Error("OPENAI_API_KEY is not set");
if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set");
if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set");

const composio = new Composio({
  apiKey: composioAPIKey as string,
});

What's happening:

dotenv/config auto loads your .env so process.env.* is available
openai gives you a Mastra compatible model wrapper
Agent is the Mastra agent that will call tools and produce answers
MCPClient connects Mastra to your Composio MCP server
Composio is used to create a Tool Router session

Create a Tool Router session for HTML/CSS to Image

typescript

async function main() {
  const session = await composio.create(
    composioUserID as string,
    {
      toolkits: ["htmlcss_to_image"],
    },
  );

  const composioMCPUrl = session.mcp.url;
  console.log("HTML/CSS to Image MCP URL:", composioMCPUrl);

What's happening:

create spins up a short-lived MCP HTTP endpoint for this user
The toolkits array contains "htmlcss_to_image" for HTML/CSS to Image access
session.mcp.url is the MCP URL that Mastra's MCPClient will connect to

Configure Mastra MCP client and fetch tools

typescript

const mcpClient = new MCPClient({
    id: composioUserID as string,
    servers: {
      nasdaq: {
        url: new URL(composioMCPUrl),
        requestInit: {
          headers: session.mcp.headers,
        },
      },
    },
    timeout: 30_000,
  });

console.log("Fetching MCP tools from Composio...");
const composioTools = await mcpClient.getTools();
console.log("Number of tools:", Object.keys(composioTools).length);

What's happening:

MCPClient takes an id for this client and a list of MCP servers
The headers property includes the x-api-key for authentication
getTools fetches the tool definitions exposed by the HTML/CSS to Image toolkit

Create the Mastra agent

typescript

const agent = new Agent({
    name: "htmlcss_to_image-mastra-agent",
    instructions: "You are an AI agent with HTML/CSS to Image tools via Composio.",
    model: "openai/gpt-5",
  });

What's happening:

Agent is the core Mastra agent
name is just an identifier for logging and debugging
instructions guide the agent to use tools instead of only answering in natural language
model uses openai("gpt-5") to configure the underlying LLM

Set up interactive chat interface

typescript

let messages: AiMessageType[] = [];

console.log("Chat started! Type 'exit' or 'quit' to end.\n");

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
  prompt: "> ",
});

rl.prompt();

rl.on("line", async (userInput: string) => {
  const trimmedInput = userInput.trim();

  if (["exit", "quit", "bye"].includes(trimmedInput.toLowerCase())) {
    console.log("\nGoodbye!");
    rl.close();
    process.exit(0);
  }

  if (!trimmedInput) {
    rl.prompt();
    return;
  }

  messages.push({
    id: crypto.randomUUID(),
    role: "user",
    content: trimmedInput,
  });

  console.log("\nAgent is thinking...\n");

  try {
    const response = await agent.generate(messages, {
      toolsets: {
        htmlcss_to_image: composioTools,
      },
      maxSteps: 8,
    });

    const { text } = response;

    if (text && text.trim().length > 0) {
      console.log(`Agent: ${text}\n`);
        messages.push({
          id: crypto.randomUUID(),
          role: "assistant",
          content: text,
        });
      }
    } catch (error) {
      console.error("\nError:", error);
    }

    rl.prompt();
  });

  rl.on("close", async () => {
    console.log("\nSession ended.");
    await mcpClient.disconnect();
    process.exit(0);
  });
}

main().catch((err) => {
  console.error("Fatal error:", err);
  process.exit(1);
});

What's happening:

messages keeps the full conversation history in Mastra's expected format
agent.generate runs the agent with conversation history and HTML/CSS to Image toolsets
maxSteps limits how many tool calls the agent can take in a single run
onStepFinish is a hook that prints intermediate steps for debugging

Complete Code

Here's the complete code to get you started with HTML/CSS to Image and Mastra AI:

typescript

import "dotenv/config";
import { openai } from "@ai-sdk/openai";
import { Agent } from "@mastra/core/agent";
import { MCPClient } from "@mastra/mcp";
import { Composio } from "@composio/core";
import * as readline from "readline";

import type { AiMessageType } from "@mastra/core/agent";

const openaiAPIKey = process.env.OPENAI_API_KEY;
const composioAPIKey = process.env.COMPOSIO_API_KEY;
const composioUserID = process.env.COMPOSIO_USER_ID;

if (!openaiAPIKey) throw new Error("OPENAI_API_KEY is not set");
if (!composioAPIKey) throw new Error("COMPOSIO_API_KEY is not set");
if (!composioUserID) throw new Error("COMPOSIO_USER_ID is not set");

const composio = new Composio({ apiKey: composioAPIKey as string });

async function main() {
  const session = await composio.create(composioUserID as string, {
    toolkits: ["htmlcss_to_image"],
  });

  const composioMCPUrl = session.mcp.url;

  const mcpClient = new MCPClient({
    id: composioUserID as string,
    servers: {
      htmlcss_to_image: {
        url: new URL(composioMCPUrl),
        requestInit: {
          headers: session.mcp.headers,
        },
      },
    },
    timeout: 30_000,
  });

  const composioTools = await mcpClient.getTools();

  const agent = new Agent({
    name: "htmlcss_to_image-mastra-agent",
    instructions: "You are an AI agent with HTML/CSS to Image tools via Composio.",
    model: "openai/gpt-5",
  });

  let messages: AiMessageType[] = [];

  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: "> ",
  });

  rl.prompt();

  rl.on("line", async (input: string) => {
    const trimmed = input.trim();
    if (["exit", "quit"].includes(trimmed.toLowerCase())) {
      rl.close();
      return;
    }

    messages.push({ id: crypto.randomUUID(), role: "user", content: trimmed });

    const { text } = await agent.generate(messages, {
      toolsets: { htmlcss_to_image: composioTools },
      maxSteps: 8,
    });

    if (text) {
      console.log(`Agent: ${text}\n`);
      messages.push({ id: crypto.randomUUID(), role: "assistant", content: text });
    }

    rl.prompt();
  });

  rl.on("close", async () => {
    await mcpClient.disconnect();
    process.exit(0);
  });
}

main();

Conclusion

You've built a Mastra AI agent that can interact with HTML/CSS to Image through Composio's Tool Router. You can extend this further by:

Adding other toolkits like Gmail, Slack, or GitHub
Building a web-based chat interface around this agent
Using multiple MCP endpoints to enable cross-app workflows

TOOLS

Supported Tools

Every HTML/CSS to Image action and event your agent gets out of the box.

Create Image

Create a hosted image from HTML/CSS or an internet-reachable webpage, including authenticated pages using request headers.

Create Image from Template

Create an image from a reusable template using the latest version or an explicitly selected version.

Create Images Batch

Create 1 to 25 hosted images from HTML/CSS or internet-reachable webpages in one request, including authenticated pages using shared or per-image headers.

Create Template

Create a reusable Handlebars HTML/CSS image template.

Delete Image

Permanently delete one generated image and clear its HCTI CDN cache.

Delete Images Batch

Permanently delete multiple generated images and clear their HCTI CDN caches.

Get or Transform Image

Download a generated image by ID, optionally converting its format, resizing it, or cropping it.

Get Usage

Return recent hourly, daily, monthly, and billing-period image usage for the connected account.

List Templates

List reusable image templates owned by the connected account, including their current version, source, and render settings.

Update Template

Create a new version of an existing template using replacement Handlebars HTML and optional CSS or render settings.

FRAMEWORKS

How to build HTML/CSS to Image MCP Agent with another framework

OpenAI Agents SDK

Use HTML/CSS to Image MCP with OpenAI Agents SDK

Claude Agent SDK

Use HTML/CSS to Image MCP with Claude Agent SDK

Claude Code

Use HTML/CSS to Image MCP with Claude Code

Claude Cowork

Use HTML/CSS to Image MCP with Claude Cowork

Codex

Use HTML/CSS to Image MCP with Codex

OpenClaw

Use HTML/CSS to Image MCP with OpenClaw

Hermes

Use HTML/CSS to Image MCP with Hermes

CLI

Use HTML/CSS to Image MCP with CLI

Google ADK

Use HTML/CSS to Image MCP with Google ADK

LangChain

Use HTML/CSS to Image MCP with LangChain

Vercel AI SDK

Use HTML/CSS to Image MCP with Vercel AI SDK

LlamaIndex

Use HTML/CSS to Image MCP with LlamaIndex

CrewAI

Use HTML/CSS to Image MCP with CrewAI

MORE TOOLKITS

Explore Other Toolkits

Toolkit marketplace

Are.na

Api Key

Are.na is a creative research platform for collecting images, links, notes, and ideas in channels. Use it to organize inspiration, build knowledge maps, and connect research across projects.

Bannerbite

Api Key

Bannerbite is a creative automation platform for generating images and videos from reusable projects and templates. It helps teams produce on-brand visual assets faster without rebuilding designs from scratch.

Builder.io

Api Key

Builder.io is a visual development platform for managing content, models, assets, and Space configuration. Use it to ship editable digital experiences faster without waiting on every code change.

Canva

Oauth2

Canva is a drag-and-drop design suite for creating professional graphics, presentations, and marketing materials. It makes it easy for anyone to design with beautiful templates and a vast library of elements.

FAQ

Frequently asked questions

With a standalone HTML/CSS to Image MCP server, the agents and LLMs can only access a fixed set of HTML/CSS to Image tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from HTML/CSS to Image and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. Mastra AI fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right HTML/CSS to Image tools.

Yes, absolutely. You can configure which HTML/CSS to Image scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your HTML/CSS to Image data and credentials are handled as safely as possible.

Start with HTML/CSS to Image.It takes 30 seconds.

Managed auth, hosted MCP servers, and every HTML/CSS to Image tool your agent needs.Free to start.

Start building

Customer stories

Teams ship real agents on Composio

GET STARTED FOR FREE BOOK A DEMO

Karan skipped his own birthday party to fix our critical issue. It was 10pm and he diverted his Waymo to help us instead. This really sets the bar — it shows the commitment you need when users rely on your software.

Harsha Gaddipati

Co-founder, Slashy

A lot of students tell us that the moment their connected tools start talking to each other inside Opennote feels almost magical. The agent just knows them, and it's immensely helped keep new users on the platform.

Abhi Arya

Co-founder, Opennote

We chose Composio over Pipedream because it delivered depth where it mattered — niche tools and tricky edge cases other platforms simply ignored. That gave us confidence to scale without compromising.

Nirman Dave

CEO, Zams

As a solo builder, shipping fast is life or death. The only way I can outcompete incumbents is by outmanoeuvring them. Getting bogged down managing agent auth would have been a death sentence.

Ryan Yu

Founder, Extra Thursday

Before Composio, adding tool integrations was slow and resource-intensive. Each one could take weeks of engineering time, and maintaining them meant constantly keeping up with API changes.

Tomisin Jenrola

Founder & CEO, SwarmZero

With hands-on help from their founder, we integrated Gmail and Google Drive in just 30 minutes. This level of personal support and commitment is exactly what startups should strive for.

Jerome Leclanche

Co-Founder, Ingram Technologies

How to integrate HTML/CSS to Image MCP with Mastra AI

Connect HTML/CSS to Image without auth hassles

Introduction

Also integrate HTML/CSS to Image with

TL;DR

What is Mastra AI?

What is the HTML/CSS to Image MCP server, and what's possible with it?

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

How the Composio SDK works

Step-by-step Guide

Prerequisites

Getting API Keys for OpenAI and Composio

Install dependencies

Set up environment variables

Import libraries and validate environment

Create a Tool Router session for HTML/CSS to Image

Configure Mastra MCP client and fetch tools

Create the Mastra agent

Set up interactive chat interface

Complete Code

Conclusion

Supported Tools

How to build HTML/CSS to Image MCP Agent with another framework

OpenAI Agents SDK

Claude Agent SDK

Claude Code

Claude Cowork

Codex

OpenClaw

Hermes

CLI

Google ADK

LangChain

Vercel AI SDK

LlamaIndex

CrewAI

Explore Other Toolkits

Are.na

Bannerbite

Builder.io

Canva

Frequently asked questions

What are the differences in Tool Router MCP and HTML/CSS to Image MCP?+

Can I use Tool Router MCP with Mastra AI?+

Can I manage the permissions and scopes for HTML/CSS to Image while using Tool Router?+

How safe is my data with Composio Tool Router?+

Start with HTML/CSS to Image.It takes 30 seconds.

Teams ship real agents on Composio