How to integrate Quaderno MCP with Codex

Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Quaderno MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or app, whichever you prefer.

Composio removes the Authentication handling completely from you. We handle the entire integration lifecycle, and all you need to do is just copy the URL below, authenticate inside Codex, and start using it.

Why use Composio?

Apart from a managed and hosted MCP server, you will get:

• CodeAct: A dedicated workbench that allows GPT to write its code to handle complex tool chaining. Reduces to-and-fro with LLMs for frequent tool calling.
• Large tool responses: Handle them to minimise context rot.
• Dynamic just-in-time access to 20,000 tools across 870+ other Apps for cross-app workflows. It loads the tools you need, so GPTs aren't overwhelmed by tools you don't need.

How to install Quaderno MCP in Codex

Codex CLI

Run the command in your terminal.

This will auto-redirect you to the Rube authentication page.

Once you're authenticated, you will be able to access the tools.

Verify the installation by running:

codex mcp list

If you otherwise prefer to use config.toml, add the following URL to it. You can get the bearer token from rube.app → Use Rube → MCP URL → Generate token

[projects."/home/user/composio"]
trust_level = "untrusted"

[mcp_servers.rube]
bearer_token_env_var = "your bearer token"
enabled = true
url = "https://rube.app/mcp"

Codex in VS Code

If you have installed Codex in VS Code.

Then: ⚙️ → MCP Settings → + Add servers → Streamable HTTP:

Add the Rube MCP URL: https://rube.app/mcp and the bearer token.

To verify, click on the Open config.toml

Make sure it's there:

[mcp_servers.composio_rube]
bearer_token_env_var = "your bearer token"
enabled = true
url = "https://rube.app/mcp"

Codex App

Codex App follows the same approach as VS Code.

1. Click ⚙️ on the bottom left → MCP Servers → + Add servers → Streamable HTTP:

2. Restart and verify if it's there in .codex/config.toml

[mcp_servers.composio_rube]
bearer_token_env_var = "your bearer token"
enabled = true
url = "https://rube.app/mcp"

3. Save, restart the extension, and start working.

The Quaderno MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Quaderno account. It provides structured and secure access to your tax automation, invoicing, and compliance workflows, so your agent can calculate taxes, generate invoices, manage contacts and products, and handle essential document delivery on your behalf.

• Automated tax rate calculation: Ask your agent to instantly determine the correct tax rate for any address or transaction type before creating invoices or processing sales.
• Invoice creation and delivery: Let your agent generate detailed invoices for customers and deliver them directly via email, ensuring seamless billing operations.
• Contact and product management: Easily create new customer or vendor contacts, add new products, or permanently delete outdated items from your Quaderno account—all through your agent.
• Expense and tax ID cleanup: Direct your agent to remove specific expenses or registered tax IDs when they're no longer needed, keeping your records tidy and up to date.
• Credit note and coupon handling: Your agent can deliver finalized credit notes to customers and permanently delete coupons as part of your accounting and revenue operations.

Conclusion

You've successfully integrated Quaderno with Codex using Composio's Rube MCP server. Now you can interact with Quaderno directly from your terminal, VS Code, or the Codex App using natural language commands.

Key benefits of this setup:

• Seamless integration across CLI, VS Code, and standalone app
• Natural language commands for Quaderno operations
• Managed authentication through Composio's Rube
• Access to 20,000+ tools across 870+ apps for cross-app workflows
• CodeAct workbench for complex tool chaining

Next steps:

• Try asking Codex to perform various Quaderno operations
• Explore cross-app workflows by connecting more toolkits
• Build automation scripts that leverage Codex's AI capabilities