> For the complete documentation index, see [llms.txt](https://xoxoday.gitbook.io/plum/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xoxoday.gitbook.io/plum/developer-resources/overview-of-reward_api/concepts.md).

# Concepts

- [Staging Environment](https://xoxoday.gitbook.io/plum/developer-resources/overview-of-reward_api/concepts/staging-environment.md): This section walks you through the process of testing our different API in a staging environment.
- [Catalog](https://xoxoday.gitbook.io/plum/developer-resources/overview-of-reward_api/concepts/catalog-refresh.md): Xoxoday offers a vast collection of vouchers that can be ordered via the Rewards API.
- [Error Handling](https://xoxoday.gitbook.io/plum/developer-resources/overview-of-reward_api/concepts/errors.md): Xoxoday Plum Pro API uses conventional HTTP status codes to indicate success or failure. Responses with a status code starting with 4xx or 5xx can be considered as failed. The API returns errors in JS
- [Standard HTTP status code summary](https://xoxoday.gitbook.io/plum/developer-resources/overview-of-reward_api/concepts/errors/standard-http-status-code-summary.md)
- [Errors related to API](https://xoxoday.gitbook.io/plum/developer-resources/overview-of-reward_api/concepts/errors/errors-related-to-api.md)
- [Exchange Rates](https://xoxoday.gitbook.io/plum/developer-resources/overview-of-reward_api/concepts/exchange-rates-1.md): This section deals with exchange rates during currency conversion.