How to integrate Harvest MCP with Atomic Agent

Atomic Agent is an open-source AI agent that runs on your machine and supports local models through llama.cpp. Connect it to 1,500+ apps through Composio, including Harvest.

This guide uses Atomic Agent's built-in Composio integration. You need Atomic Agent v0.5.6 or later, your own Composio API key, and a Harvest account. See the Atomic Agent documentation for installation instructions.

How Atomic Agent connects to Harvest

Atomic Agent connects to Composio's Tool Router over Streamable HTTP MCP. It discovers the tools needed for your request, and Composio handles account authentication.

Execution and account-connection tools follow Atomic Agent's configured approval policy. Review any approval prompt before allowing an action on your connected account.

Connect Harvest to Atomic Agent

1. Sign up or sign in to the Composio dashboard. Copy your API key.
2. In Atomic Agent, open the Integrations tab and select Composio. Select API key, press e, paste the key, and press Enter. The tools become available immediately, without a restart.
3. Ask Atomic Agent to do something in Harvest. It searches Composio for the right tool.
4. On first use, open the sign-in link returned in the chat. Connect your Harvest account, then return to Atomic Agent to continue.

Headless setup

Add the following line to ~/.atomic-agent/.env, replacing YOUR_COMPOSIO_API_KEY with your key. Start Atomic Agent after saving the file.

The Harvest MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Harvest account. It provides structured and secure access to your time-tracking, invoicing, and project management data, so your agent can create clients, log expenses, send invoices, record payments, and manage estimates automatically on your behalf.

• Client and contact management: Seamlessly create new clients and add contacts to keep your client list up to date without manual entry.
• Estimate creation and communication: Automatically generate new estimates, categorize line items, and send estimate messages or updates to clients.
• Expense tracking automation: Log new expense entries against projects, ensuring accurate financial records and effortless cost tracking.
• Streamlined invoicing and payments: Create professional invoices, categorize invoice items, send invoice notifications, and record payments as soon as they happen.
• Project financial workflow optimization: Let your agent handle the full cycle—from creating clients to sending invoices and tracking payments—saving your team valuable time and reducing errors.

Use Harvest from Atomic Agent

With your account connected, ask Atomic Agent to work with Harvest in natural language. You can connect more apps through the same Composio integration as you need them.

Visit the Atomic Agent website or inspect the Atomic Agent source code.