How to integrate Xero MCP with Mastra AI

This guide walks you through connecting Xero to Mastra AI using the Composio tool router. By the end, you'll have a working Xero agent that can list all active xero tenant connections, show latest contacts added this week, retrieve all open quotes for this month through natural language commands. This guide will help you understand how to give your Mastra AI agent real control over a Xero account through Composio's Xero MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Xero is cloud-based accounting software for small businesses, offering invoicing, bookkeeping, and real-time financial reports. It helps you manage business finances efficiently from anywhere.

41 Tools

Introduction

This guide walks you through connecting Xero to Mastra AI using the Composio tool router. By the end, you'll have a working Xero agent that can list all active xero tenant connections, show latest contacts added this week, retrieve all open quotes for this month through natural language commands.

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

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

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

The Xero MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Xero account. It provides structured and secure access to your accounting data, so your agent can retrieve contacts, manage connections, update invoices, and monitor quotes automatically on your behalf.

  • Connection management: Instantly list all active Xero tenant connections linked to your account, making it easy for your agent to select and operate on the right organization.
  • Contact retrieval and lookup: Fetch detailed, up-to-date lists of business contacts including filtering, paging, and incremental updates to keep your records synchronized and actionable.
  • Quote management and tracking: Retrieve, filter, or search through your sales quotes so your agent can help you stay on top of prospective business and follow up faster.
  • Invoice updating and automation: Modify details of existing invoices—such as amounts, due dates, and line items—allowing your agent to keep your invoicing accurate and up to date without manual edits.

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 Xero 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 Xero

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

  const composioMCPUrl = session.mcp.url;
  console.log("Xero MCP URL:", composioMCPUrl);
What's happening:
  • create spins up a short-lived MCP HTTP endpoint for this user
  • The toolkits array contains "xero" for Xero 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 Xero toolkit
8

Create the Mastra agent

typescript
const agent = new Agent({
    name: "xero-mastra-agent",
    instructions: "You are an AI agent with Xero 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: {
        xero: 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 Xero 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 Xero 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: ["xero"],
  });

  const composioMCPUrl = session.mcp.url;

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

  const composioTools = await mcpClient.getTools();

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

Create Bank Transaction

Create a bank transaction in Xero.

Create Contact

Create a new contact in Xero.

Create Invoice

Create a new invoice in Xero.

Create Item

Create an inventory item in Xero.

Create Manual Journal

Create one or more manual journals (journal entries) in Xero with journal lines.

Create Payment

Create a payment in Xero to link an invoice with a bank account transaction.

Create Purchase Order

Create a purchase order in Xero to order goods/services from suppliers.

Get Account

Retrieve a specific account from Xero's chart of accounts by its unique ID.

Get Asset

Retrieve a specific asset by ID from Xero.

Get Balance Sheet Report

Retrieve Balance Sheet report from Xero.

Get Budget

Retrieve a budget from Xero.

Get Connections

Tool to list active Xero connections.

Get Contacts

Tool to retrieve a list of contacts.

Get Invoice

Retrieve a specific invoice by ID from Xero.

Get Item

Retrieve a specific item by ID from Xero.

Get Manual Journal

Retrieve a specific manual journal by ID from Xero.

Get Organisation

Retrieve organisation details from Xero.

Get Profit & Loss Report

Retrieve Profit & Loss report from Xero.

Get Project

Retrieve a specific project by ID from Xero.

Get Purchase Order

Retrieve a specific purchase order by ID from Xero.

Get Quotes

Tool to retrieve a list of quotes.

Get Trial Balance Report

Retrieve Trial Balance report from Xero.

List Accounts

Retrieve chart of accounts from Xero.

List Assets

Retrieve fixed assets from Xero.

List Attachments

List all attachments for a specific entity in Xero (invoice, contact, etc.

List Bank Transactions

Retrieve bank transactions from Xero.

List Credit Notes

Retrieve list of credit notes from Xero.

List Files

Retrieve files from Xero Files.

List Folders

Retrieve folders from Xero Files.

List Invoices

Retrieve a list of invoices from Xero.

List Items

Retrieve items (inventory/products) from Xero.

List Journals

Retrieve journals from Xero.

List Manual Journals

Retrieve manual journals from Xero.

List Payments

Retrieve list of payments from Xero.

List Projects

Retrieve projects from Xero.

List Purchase Orders

Retrieve list of purchase orders from Xero.

List Tax Rates

Retrieve tax rates from Xero.

List Tracking Categories

Retrieve tracking categories from Xero.

Update Invoice

Tool to update an existing invoice.

Update Contact

Update an existing contact in Xero.

Upload Attachment

Upload a file attachment to a Xero entity (invoice, contact, etc.

FAQ

Frequently asked questions

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

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

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