> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dualentry.com/llms.txt
> Use this file to discover all available pages before exploring further.

# DualEntry Public API

> Everything for building against the DualEntry Public API: what it is, your first request, authentication, and task-specific guides.

The DualEntry Public API is a RESTful, JSON-based, server-to-server interface for reading and writing your organization's accounting data. Requests authenticate with an API key in the `X-API-KEY` header, sent to `https://api.dualentry.com`; every endpoint requires authentication and is rate-limited. See [Versioning](/developers/guides/versioning-policy) for how the API is versioned and which version to build against.

## What you can build

DualEntry's policy is that anything you can do in the DualEntry UI, you can do through the API. If you find a gap where that isn't true, reach out and we'll close it.

## What this section covers

* **[Quickstart](./quickstart)**: get an API key and make your first authenticated request in under five minutes.
* **[Authentication](./authentication)**: how API keys work, the roles they carry, and both `403` failure modes.
* **[API Keys](./api-keys/index)**: issue, send, and replace an API key.
* **[Core Concepts](./core-concepts/index)**: rate limits, pagination, errors, and idempotent writes.
* **[Building Blocks](./building-blocks/index)**: task-specific guides for attachments, bank feeds, and tax.

## Where to go next

If you're building a production integration for the partner program rather than a one-off script, see [How Custom Integrations Work](/developers/guides/integrations-and-tools/how-custom-integrations-work).