# Introduction

The DualEntry Public API provides programmatic access to your organization's accounting data. It's designed for server-to-server integrations using RESTful conventions and JSON format.

## Overview

- **RESTful API**: Standard HTTP methods (GET, POST, PUT, DELETE)
- **JSON Format**: All requests and responses use JSON
- **Secure**: API key-based authentication
- **Versioned**: All endpoints under `/v1/` for stability


## What You Can Build

Build integrations to automate accounting workflows, sync data with external systems, and create custom financial applications.

**Common Use Cases**: Automated invoicing, data synchronization with CRM/ERP systems, custom reporting, third-party integrations with payment processors or e-commerce platforms.

## API Resources

The API provides access to:

- **Setup**: Accounts, Items, Classifications
- **Master Data**: Companies, Customers, Vendors
- **Transactions**: Invoices, Bills, Journal Entries, Payments, Purchase Orders
- **Automation**: Recurring Transactions, Attachments


## Getting Started

1. Get an API key from your DualEntry administrator
2. Include the API key in the `X-API-KEY` header with every request
3. All endpoints require authentication and are rate-limited


**Base URLs**:

- Production: `https://api.dualentry.com`
- Development: `https://api-dev.dualentry.com`


**Next:** [Learn about Authentication →](/authentication)