> ## 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.

# Core Concepts

> The mechanics every DualEntry Public API integration needs to get right: rate limits, pagination, errors, and idempotent writes.

These pages cover the parts of the DualEntry Public API that apply across every resource and endpoint, rather than to any one of them. Read them once, before you write much integration code; the specifics change less often than the resource-level details.

## What this section covers

* **[Rate Limiting](./rate-limiting)**: request quotas and how to request an override.
* **[Pagination](./pagination)**: how list endpoints page, and how to fetch a complete dataset.
* **[Error Handling](./errors)**: DualEntry's error model and which failures are safe to retry.
* **[Idempotency and Write Validation](./idempotency-and-write-validation)**: how to make a write safe to retry without creating a duplicate record.

## Where to go next

For how the API is versioned and what counts as a breaking change, see [Versioning](/developers/guides/versioning-policy). For task-specific guidance (attachments, bank feeds, tax), see [Building Blocks](../building-blocks/index).