# How to connect Customjs to Claude Cowork ```json { "title": "How to connect Customjs to Claude Cowork", "toolkit": "Customjs", "toolkit_slug": "customjs", "framework": "Claude Cowork", "framework_slug": "claude-cowork", "url": "https://composio.dev/toolkits/customjs/framework/claude-cowork", "markdown_url": "https://composio.dev/toolkits/customjs/framework/claude-cowork.md", "updated_at": "2026-05-12T10:08:04.911Z" } ``` ## Introduction Cowork is Anthropic's AI agent for knowledge work. Think of it as Claude Code for everything else. It works autonomously with your computer, local files, and applications to accomplish complex tasks. This guide walks you through the easiest and most secure way to connect your Customjs account to Cowork via Composio Connect, enabling it to convert this HTML invoice to PDF file, take a screenshot of your company homepage, merge these three PDF reports into one, and more such actions on your behalf without compromising your account security. ## Also integrate Customjs with - [OpenAI Agents SDK](https://composio.dev/toolkits/customjs/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/customjs/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/customjs/framework/claude-code) - [Codex](https://composio.dev/toolkits/customjs/framework/codex) - [OpenClaw](https://composio.dev/toolkits/customjs/framework/openclaw) - [Hermes](https://composio.dev/toolkits/customjs/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/customjs/framework/cli) - [Google ADK](https://composio.dev/toolkits/customjs/framework/google-adk) - [LangChain](https://composio.dev/toolkits/customjs/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/customjs/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/customjs/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/customjs/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/customjs/framework/crew-ai) ## Connect Customjs to Claude Cowork ### Connecting Customjs to Claude Cowork 1. Open Customize In Claude Desktop, click Customize in the left sidebar, then select Connectors and click the + icon at the top. 2. Add the Composio MCP server Click Add custom connector and paste in the Composio MCP server URL: ```bash https://connect.composio.dev/mcp ``` ## What is Claude Cowork? Claude Cowork is Anthropic's agent for general knowledge work. It can use your computer, files, and connected applications to complete longer-running tasks across your work tools. With Composio Connect, Cowork can securely access apps like Customjs through MCP without you sharing account credentials directly with the agent. ## What is the Customjs MCP server, and what's possible with it? The Customjs MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Customjs account. It provides structured and secure access to your Customjs automations, so your agent can convert HTML to PDFs and images, capture website screenshots, merge PDF files, and run custom browser scripts on your behalf. - HTML to PDF and PNG conversion: Instantly generate high-quality PDFs or PNG images from any HTML markup or template using agent commands. - Automated webpage screenshot capture: Have your agent take precise, up-to-date screenshots of any public webpage for documentation, monitoring, or reporting. - PDF merging and file handling: Let your agent combine multiple PDF files into a single document, perfect for reports or document consolidation tasks. - Headless browser automation with Puppeteer: Empower your agent to execute custom Puppeteer scripts—scraping data or capturing advanced browser screenshots as PNGs. - Secure API key authentication: Ensure that all actions are performed securely by verifying your Customjs API key through the agent-managed authentication flow. ## Supported Tools | Tool slug | Name | Description | |---|---|---| | `CUSTOMJS_AUTHENTICATE_API_KEY` | Authenticate CustomJS API Key | Authenticate and validate a CustomJS API key. Returns workspace details, request limits, and decoded JWT token information including user email. Use this to verify an API key is valid before making other CustomJS API calls. | | `CUSTOMJS_CONVERT_HTML_TO_PDF` | Convert HTML to PDF | Convert HTML content to a PDF document. Use this tool to generate PDF files from raw HTML markup. Supports: - Complete HTML documents or fragments - Inline CSS styling (colors, fonts, tables, borders, backgrounds) - Unicode characters and special symbols - Multi-page documents Returns raw PDF bytes suitable for file storage or download. | | `CUSTOMJS_CONVERT_HTML_TO_PNG` | Convert HTML to PNG | Tool to convert HTML string to PNG image. Use when you need a PNG from HTML after preparing your markup. | | `CUSTOMJS_MERGE_PDFS` | Merge multiple PDFs into one | Merge multiple PDF files from URLs into a single PDF document. Use this tool when you need to combine two or more PDF documents into one. The PDFs are merged in the order provided. All input URLs must be publicly accessible. Returns a downloadable merged PDF file. | | `CUSTOMJS_RUN_PUPPETEER_SCRIPT` | Run Puppeteer Script | Execute a Puppeteer script in a headless browser and capture a screenshot. Use this tool for browser automation tasks such as navigating to URLs, interacting with page elements, extracting data, or capturing visual snapshots of web pages. The script runs in a sandboxed Puppeteer environment with access to a 'page' object. | ## Supported Triggers None listed. ## Creating MCP Server - Stand-alone vs Composio SDK The Customjs MCP server connects Claude Cowork to your Customjs account through Composio. Once connected, Cowork can use the available Customjs tools and triggers to complete tasks on your behalf. ## Complete Code None listed. ## How to build Customjs MCP Agent with another framework - [OpenAI Agents SDK](https://composio.dev/toolkits/customjs/framework/open-ai-agents-sdk) - [Claude Agent SDK](https://composio.dev/toolkits/customjs/framework/claude-agents-sdk) - [Claude Code](https://composio.dev/toolkits/customjs/framework/claude-code) - [Codex](https://composio.dev/toolkits/customjs/framework/codex) - [OpenClaw](https://composio.dev/toolkits/customjs/framework/openclaw) - [Hermes](https://composio.dev/toolkits/customjs/framework/hermes-agent) - [CLI](https://composio.dev/toolkits/customjs/framework/cli) - [Google ADK](https://composio.dev/toolkits/customjs/framework/google-adk) - [LangChain](https://composio.dev/toolkits/customjs/framework/langchain) - [Vercel AI SDK](https://composio.dev/toolkits/customjs/framework/ai-sdk) - [Mastra AI](https://composio.dev/toolkits/customjs/framework/mastra-ai) - [LlamaIndex](https://composio.dev/toolkits/customjs/framework/llama-index) - [CrewAI](https://composio.dev/toolkits/customjs/framework/crew-ai) ## Related Toolkits - [Supabase](https://composio.dev/toolkits/supabase) - Supabase is an open-source backend platform offering scalable Postgres databases, authentication, storage, and real-time APIs. It lets developers build modern apps without managing infrastructure. - [Codeinterpreter](https://composio.dev/toolkits/codeinterpreter) - Codeinterpreter is a Python-based coding environment with built-in data analysis and visualization. It lets you instantly run scripts, plot results, and prototype solutions inside supported platforms. - [GitHub](https://composio.dev/toolkits/github) - GitHub is a code hosting platform for version control and collaborative software development. It streamlines project management, code review, and team workflows in one place. - [Ably](https://composio.dev/toolkits/ably) - Ably is a real-time messaging platform for live chat and data sync in modern apps. It offers global scale and rock-solid reliability for seamless, instant experiences. - [Abuselpdb](https://composio.dev/toolkits/abuselpdb) - Abuselpdb is a central database for reporting and checking IPs linked to malicious online activity. Use it to quickly identify and report suspicious or abusive IP addresses. - [Alchemy](https://composio.dev/toolkits/alchemy) - Alchemy is a blockchain development platform offering APIs and tools for Ethereum apps. It simplifies building and scaling Web3 projects with robust infrastructure. - [Algolia](https://composio.dev/toolkits/algolia) - Algolia is a hosted search API that powers lightning-fast, relevant search experiences for web and mobile apps. It helps developers deliver instant, typo-tolerant, and scalable search without complex infrastructure. - [Anchor browser](https://composio.dev/toolkits/anchor_browser) - Anchor browser is a developer platform for AI-powered web automation. It transforms complex browser actions into easy API endpoints for streamlined web interaction. - [Apiflash](https://composio.dev/toolkits/apiflash) - Apiflash is a website screenshot API for programmatically capturing web pages. It delivers high-quality screenshots on demand for automation, monitoring, or reporting. - [Apiverve](https://composio.dev/toolkits/apiverve) - Apiverve delivers a suite of powerful APIs that simplify integration for developers. It's designed for reliability and scalability so you can build faster, smarter applications without the integration headache. - [Appcircle](https://composio.dev/toolkits/appcircle) - Appcircle is an enterprise-grade mobile CI/CD platform for building, testing, and publishing mobile apps. It streamlines mobile DevOps so teams ship faster and with more confidence. - [Appdrag](https://composio.dev/toolkits/appdrag) - Appdrag is a cloud platform for building websites, APIs, and databases with drag-and-drop tools and code editing. It accelerates development and iteration by combining hosting, database management, and low-code features in one place. - [Appveyor](https://composio.dev/toolkits/appveyor) - AppVeyor is a cloud-based continuous integration service for building, testing, and deploying applications. It helps developers automate and streamline their software delivery pipelines. - [Backendless](https://composio.dev/toolkits/backendless) - Backendless is a backend-as-a-service platform for mobile and web apps, offering database, file storage, user authentication, and APIs. It helps developers ship scalable applications faster without managing server infrastructure. - [Baserow](https://composio.dev/toolkits/baserow) - Baserow is an open-source no-code database platform for building collaborative data apps. It makes it easy for teams to organize data and automate workflows without writing code. - [Bench](https://composio.dev/toolkits/bench) - Bench is a benchmarking tool for automated performance measurement and analysis. It helps you quickly evaluate, compare, and track your systems or workflows. - [Better stack](https://composio.dev/toolkits/better_stack) - Better Stack is a monitoring, logging, and incident management solution for apps and services. It helps teams ensure application reliability and performance with real-time insights. - [Bitbucket](https://composio.dev/toolkits/bitbucket) - Bitbucket is a Git-based code hosting and collaboration platform for teams. It enables secure repository management and streamlined code reviews. - [Blazemeter](https://composio.dev/toolkits/blazemeter) - Blazemeter is a continuous testing platform for web and mobile app performance. It empowers teams to automate and analyze large-scale tests with ease. - [Blocknative](https://composio.dev/toolkits/blocknative) - Blocknative delivers real-time mempool monitoring and transaction management for public blockchains. Instantly track pending transactions and optimize blockchain interactions with live data. ## Frequently Asked Questions ### What are the differences in Tool Router MCP and Customjs MCP? With a standalone Customjs MCP server, the agents and LLMs can only access a fixed set of Customjs tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Customjs and many other apps based on the task at hand, all through a single MCP endpoint. ### Can I use Tool Router MCP with Claude Cowork? Yes, you can. Claude Cowork 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 Customjs tools. ### Can I manage the permissions and scopes for Customjs while using Tool Router? Yes, absolutely. You can configure which Customjs 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. ### How safe is my data with Composio Tool Router? 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 Customjs data and credentials are handled as safely as possible. --- [See all toolkits](https://composio.dev/toolkits) · [Composio docs](https://docs.composio.dev/llms.txt)