# 概述

Offer chains are a sequence of steps, each containing an item that users receive for free or purchase as part of an active offer. Offer chains can include exclusive items available only within the chain, as well as items at discounted prices compared to store prices. For detailed information on configuring this marketing tool, refer to the [Offer chains](https://developers.xsolla.com/zh/liveops/promotion-tools/offer-chains/) section.

To configure offer chains, use API calls from the **Admin** subsection. To display chains and implement the logic for working with items that users receive, use API calls from the **Client** subsection.

<b>Example of offer chain configuration flow:</b>

1. Create items using the API calls from the **Admin** subsection of the [Virtual items and currency](https://developers.xsolla.com/zh/api/catalog/virtual-items-currency-overview) or [Bundles](https://developers.xsolla.com/zh/api/catalog/bundles-admin) groups.

2. Create a chain using the [Create offer chain](https://developers.xsolla.com/zh/api/liveops/offer-chain-admin/admin-create-offer-chain) API call. To activate the chain, pass the `is_enabled: true` parameter.

3. Implement offer chain display. To do this, request the list of available chains using the [Get current user's offer chains](https://developers.xsolla.com/zh/api/liveops/offer-chain-client/get-offer-chains-list) API call. The response contains all active chains with their steps and statuses.

4. Implement the logic for working with items that users receive:

- If the step item is free, use the [Claim free offer chain step](https://developers.xsolla.com/zh/api/liveops/offer-chain-client/claim-user-offer-chain-step-reward) API call. Pass `offer_chain_id` and `step_number` in the request.

- If the step item is paid, use the [Create order for paid offer chain step](https://developers.xsolla.com/zh/api/liveops/offer-chain-client/order-user-offer-chain-step-reward) API call. Pass `offer_chain_id` and `step_number` in the request. The response returns an `order_id` and token to open the payment UI.

5. Configure order status tracking, e.g., using [webhooks](https://developers.xsolla.com/zh/webhooks/section/overview), to promptly receive data on claimed or purchased items and grant them to the user.

![Reward chain configuration flow](https://cdn.xsolla.net/developers/current/images/api_docs/offer-chains-overview.svg)