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

# Overview

> Core concepts and best practices for using the Partoo API securely and efficiently.

Welcome to **API Fundamentals**. This section covers everything you need to know to build robust, secure, and well-behaved integrations with the Partoo API.

<CardGroup cols={2}>
  <Card title="Error Codes and Handling" href="/guides/api/getting-started/api-fundamentals/errors" icon="bug">
    Understand and troubleshoot common HTTP and JSON error responses.
  </Card>

  <Card title="Rate Limiting" href="/guides/api/getting-started/api-fundamentals/rate-limits" icon="gauge">
    Learn how to work within API rate limits and handle 429 responses.
  </Card>

  <Card title="Security and API Key Usage" href="/guides/api/getting-started/api-fundamentals/security" icon="key">
    Follow best practices for API key usage and avoid common security mistakes.
  </Card>

  <Card title="Retry Tips and Best Practices" href="/guides/api/getting-started/api-fundamentals/retry-tips" icon="rotate">
    Implement smart retry logic to recover from transient errors and rate limits.
  </Card>
</CardGroup>