How to integrate Quaderno MCP with Mastra AI

This guide walks you through connecting Quaderno to Mastra AI using the Composio tool router. By the end, you'll have a working Quaderno agent that can calculate tax rate for a u.s. sale, create an invoice for a new customer, email finalized invoice to a client through natural language commands. This guide will help you understand how to give your Mastra AI agent real control over a Quaderno account through Composio's Quaderno MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Quaderno is a tax compliance platform that automates tax calculations, invoicing, and reporting for businesses globally. It helps you streamline tax processes and stay compliant without manual effort.

76 Tools

Introduction

This guide walks you through connecting Quaderno to Mastra AI using the Composio tool router. By the end, you'll have a working Quaderno agent that can calculate tax rate for a u.s. sale, create an invoice for a new customer, email finalized invoice to a client through natural language commands.

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

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

Also integrate Quaderno with

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 Quaderno tools
  • Connect Mastra's MCP client to the Composio generated MCP URL
  • Fetch Quaderno 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 Quaderno 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 Quaderno MCP server, and what's possible with it?

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.

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:

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

Step-by-step Guide

Step by step09 STEPS
1

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
2

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 Quaderno through MCP.
3

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
4

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
5

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
6

Create a Tool Router session for Quaderno

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

  const composioMCPUrl = session.mcp.url;
  console.log("Quaderno MCP URL:", composioMCPUrl);
What's happening:
  • create spins up a short-lived MCP HTTP endpoint for this user
  • The toolkits array contains "quaderno" for Quaderno access
  • session.mcp.url is the MCP URL that Mastra's MCPClient will connect to
7

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 Quaderno toolkit
8

Create the Mastra agent

typescript
const agent = new Agent({
    name: "quaderno-mastra-agent",
    instructions: "You are an AI agent with Quaderno 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
9

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: {
        quaderno: 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 Quaderno 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 Quaderno 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: ["quaderno"],
  });

  const composioMCPUrl = session.mcp.url;

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

  const composioTools = await mcpClient.getTools();

  const agent = new Agent({
    name: "quaderno-mastra-agent",
    instructions: "You are an AI agent with Quaderno 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: { quaderno: 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 Quaderno 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 Quaderno action and event your agent gets out of the box.

Add Expense Payment

Adds a payment to an existing expense in Quaderno.

Calculate Tax Rate

Tool to calculate applicable tax rate for given address and transaction type.

Create Contact

Tool to create a new contact (customer or vendor).

Create Coupon

Tool to create a new discount coupon in Quaderno.

Create Estimate

Creates a new estimate/quote in Quaderno for a customer with line items.

Create Evidence

Tool to create a new location evidence for tax compliance.

Create Expense

Tool to create a business expense in Quaderno.

Create Invoice

Creates a new invoice in Quaderno for a customer with line items.

Create Product

Creates a new product that can be used as a line item in invoices, credit notes, and expenses.

Create Receipt

Creates a new receipt in Quaderno documenting payment for goods or services.

Create Recurring

Tool to create a recurring document in Quaderno that automatically generates invoices on a schedule.

Create Report Request

Tool to request a new report generation in Quaderno.

Create Tax ID

Tool to create a tax ID in a specific jurisdiction.

Create Transaction

Tool to create a sale or refund transaction in Quaderno.

Create Webhook

Tool to create a new webhook in Quaderno to receive event notifications.

Delete Contact

Tool to permanently delete a contact by ID.

Delete Coupon

Tool to permanently delete a coupon.

Delete Estimate

Permanently deletes an estimate from Quaderno by its ID.

Delete Expense

Permanently deletes an expense from Quaderno by its ID.

Delete Product

Tool to permanently delete a product by ID.

Delete Recurring

Tool to permanently delete a recurring by ID.

Delete Tax ID

Permanently deletes a registered tax ID from your Quaderno account.

Delete Webhook

Tool to permanently delete a webhook by ID.

Deliver Credit Note

Sends a credit note to the customer via email.

Deliver Estimate

Delivers an estimate to the customer via email.

Deliver Invoice

Delivers an invoice to the customer via email.

Deliver Receipt

Sends a receipt to the customer via email.

Get Authorization

Tool to retrieve account credentials and verify API access.

Get Estimate

Tool to retrieve the details of an existing estimate by ID.

List Contacts

Tool to list contacts, paginated and filterable by name, email, or tax ID.

List Coupons

Tool to list all coupons.

List Credits

Tool to list all credit notes from Quaderno.

List Estimates

Tool to list all estimates in the account, paginated and sorted by creation date (newest first).

List Evidence

Tool to list all evidence objects.

List Expenses

List all expenses from Quaderno with pagination support.

List Invoices

Tool to list all invoices from Quaderno with filtering support.

List Tax Jurisdictions

Tool to list all tax jurisdictions.

List Products

List all products (goods and services) from your Quaderno account.

List Receipts

Tool to list all receipts from Quaderno with optional filtering by search query, date range, payment state, processor ID, or customer ID.

List Recurrings

List all recurring documents (invoices, expenses, or estimates) from your Quaderno account.

List Registered Tax IDs

Tool to list all registered tax IDs.

List Reporting Requests

Retrieves all reporting requests for the account with their current status and download URLs.

List Sessions

List Quaderno Checkout sessions with optional filtering and pagination.

List Tax Codes

Tool to list all supported tax codes.

List Webhooks

Tool to list all webhooks.

Mark Invoice Uncollectible

Tool to mark an invoice as uncollectible (bad debt).

Ping API Service

Tool to check if the Quaderno API service is up and verify credentials.

Record Invoice Payment

Tool to record a payment on an existing invoice.

Remove Invoice Payment

Tool to remove a payment from an invoice.

Retrieve Contact

Tool to retrieve details of an existing contact by ID.

Retrieve Contact by Processor ID

Tool to retrieve a contact by external payment processor customer ID and gateway name.

Retrieve Coupon

Retrieve detailed information about a specific coupon by its ID.

Retrieve Credit Note

Tool to retrieve details of an existing credit note by ID.

Retrieve Evidence

Retrieves a specific evidence object by its ID.

Retrieve Expense

Tool to retrieve details of an existing expense by ID.

Retrieve Invoice

Tool to retrieve details of an existing invoice by ID.

Retrieve Tax Jurisdiction

Tool to retrieve a tax jurisdiction by ID.

Retrieve Product

Tool to retrieve details of an existing product by ID.

Retrieve Receipt

Tool to retrieve details of an existing receipt by ID.

Retrieve Recurring

Tool to retrieve details of an existing recurring document by ID.

Retrieve Reporting Request

Tool to retrieve the status and download URL of a specific report request by ID.

Retrieve Tax Code

Tool to retrieve a specific tax code by ID.

Retrieve Tax ID

Tool to retrieve details of a specific tax ID by its ID.

Update Contact

Tool to update an existing contact in Quaderno.

Update Coupon

Tool to update an existing coupon.

Update Credit Note

Tool to update a credit note.

Update Estimate

Updates an existing estimate in Quaderno by modifying allowed fields.

Update Evidence

Tool to update an evidence object.

Update Expense

Updates an existing expense in Quaderno by modifying allowed fields.

Update Invoice

Updates an existing invoice in Quaderno by modifying allowed fields.

Update product

Tool to update a product; unspecified fields remain unchanged.

Update Recurring

Tool to update a recurring document in Quaderno.

Update Tax ID

Tool to update an existing tax ID in Quaderno.

Update Webhook

Tool to update an existing webhook configuration.

Validate Tax ID

Tool to validate a tax ID.

Void Credit Note

Tool to void a credit note.

FAQ

Frequently asked questions

With a standalone Quaderno MCP server, the agents and LLMs can only access a fixed set of Quaderno tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Quaderno 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 Quaderno tools.

Yes, absolutely. You can configure which Quaderno 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 Quaderno data and credentials are handled as safely as possible.

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