> ## Documentation Index > Fetch the complete documentation index at: https://docs.renaiss.xyz/llms.txt > Use this file to discover all available pages before exploring further. # List buyback offers > Find cards this wallet can sell back through your integration. Each offer includes its payout tiers and expiry times. 1. Refresh the wallet’s offers before showing the payout. 2. Read `buybackTiers` in order. The first unexpired tier’s `amountInUsdt` is the current price. The `expiresAt` of the last tier with a positive amount is the offer deadline. 3. Have the wallet sign the reviewed offer to [settle the buyback](https://docs.renaiss.xyz/api-reference/gacha/settle-buyback.md). See [buybacks and delivery](https://docs.renaiss.xyz/gacha.md#buybacks-and-delivery) for what happens to a card after the window closes. ## Request Builder key required ## Response ## Error codes Match the HTTP status and response text to a row below. For guidance on codes shared across endpoints, see [Error meanings and recovery](https://docs.renaiss.xyz/api-reference/errors.md). | HTTP | Error code | Text field | Response text and recovery | | :- | :- | :- | :- | | `400` | `WRONG_REQUEST_PARAMS` | `message` | `Bad request - invalid parameters` A field is missing or has the wrong form. Fix the request and send it again. | | `401` | `API_AUTH_INVALID_CREDENTIAL` | `error` | `Invalid authentication credential` The builder key is malformed, unknown, expired or revoked. Check the key. Do not retry with the same key. | | `401` | `API_AUTH_MISSING_CREDENTIAL` | `error` | `Required authentication credential is missing` No builder key was sent. Send your builder key in the `x-builder-api-key` header. | | `403` | `API_AUTH_CREDENTIAL_NOT_ALLOWED` | `error` | `Credential is not allowed by this policy` This route takes a builder key only. Remove the `Authorization` header and any other credential, then send the request again. | | `403` | `GACHA_V3_BUILDER_NOT_ACCEPTED_ON_PUBLIC_API` | `error` | `This builder checks out on its own surface, not on the public API` This builder key cannot be used on this API. Do not retry; contact Renaiss. | | `429` | `API_AUTH_RATE_LIMITED` | `error` | `Authentication rate limit exceeded` The builder key hit its rate limit. Wait a little, then retry at a lower rate. | | `500` | `API_AUTH_ERROR` | `error` | `Internal server error` | | `500` | `FUNCTION_ERROR` | `error` | `Internal server error` | | `500` | `OFFER_QUERY_FAILED` | `error` | `Internal server error` Read again after a short wait. | | `500` | Other code | `error` | `Internal server error` | ## OpenAPI ````yaml api-reference/openapi.json GET /v2/gacha/buyback/offers openapi: 3.1.1 info: version: 1.0.0 title: Renaiss Builder API v2 description: >- Builder API v2 for gacha, marketplace and redemption with external wallets on BNB Smart Chain (chain 56). Any active, approved builder key can prepare purchases. A collectible is an item a wallet can pull, trade, sell back or redeem, such as a card. This API calls every such item a collectible (e.g. cards), in paths, fields and descriptions. Browse publicly, then prepare and sign actions with the buyer wallet. Gacha history and buyback offers require your builder key; purchases and buybacks also require a wallet action signature. Private shipping data and redemption require a wallet access token, which the API issues from a registered partner origin after the wallet signs a sign-in message. Gacha and marketplace never use a wallet access token. Keep the builder key on your backend. The acting wallet is an EOA or a deployed ERC-1271 contract account. EIP-7702 delegated accounts, ERC-6492 and ERC-8010 wrapped signatures and Renaiss-managed Safes are refused (a Safe only after its signature verified). A pull to a contract account that cannot receive ERC-721 tokens returns `CONTRACT_WALLET_CANNOT_RECEIVE_NFT`. A failed chain read returns `API_AUTH_ERROR` (500). Wallet access tokens and redemption are EOA only. servers: - url: https://api.renaiss.xyz description: BNB Smart Chain - url: https://dev-api.renaiss.xyz description: BNB testnet security: [] tags: - name: Gacha v2 description: >- Direct-EOA pack browsing, purchases, collectible (e.g. card) reveals, purchase history and buybacks. Start here; no wallet access token is needed. - name: Marketplace description: >- Public collectible (e.g. card) browsing and external-wallet asks, bids, purchases and cancellations. Trading requires builder authorization and wallet action signatures. - name: Users description: >- What one wallet address has and did: its collectibles (e.g. cards), their total market value and its activities. The whole wallet, whichever builder it used. Requires your builder key only. - name: Redemption description: >- Shipping eligibility, quotes, redemption preparation, submission and tracking. Requires your builder key and a wallet access token for the same wallet. - name: Wallet access tokens description: >- Get, refresh and revoke the wallet access tokens that Redeem needs. The wallet signs a sign-in message (valid 5 minutes, one use); the API returns a wallet access token (15 minutes) and a refresh token (7 days, single use). Register exact partner frontend origins with Renaiss before use. Gacha and marketplace never use a wallet access token. paths: /v2/gacha/buyback/offers: get: tags: - Gacha v2 summary: List a wallet's eligible buybacks for this builder description: >- Find cards this wallet can sell back through your integration. Each offer includes its payout tiers and expiry times. parameters: - schema: type: string required: true name: buyerWalletAddress in: query - schema: type: integer minimum: 1 maximum: 100 default: 20 required: false name: limit in: query - schema: type: - integer - 'null' minimum: 0 maximum: 10000 default: 0 required: false name: offset in: query responses: '200': description: Success content: application/json: schema: type: object properties: offers: type: array items: type: object properties: cardPackId: type: string settlementId: type: string description: >- 32 bytes encoded as 0x followed by 64 hexadecimal digits. tokenId: type: string vendingMachineAddress: type: string description: >- 20-byte, 0x-prefixed wallet or contract address. Use lowercase or a valid checksum. buybackTiers: type: array items: type: object properties: buybackPercentage: type: number description: >- Percent of the card's base value, e.g. 90 means 90%. amountInUsdt: type: string description: Price in USDT with 18 decimals in this tier. expiresAt: type: string description: >- When this tier ends. The tier still applies at that moment. required: - buybackPercentage - amountInUsdt - expiresAt description: >- Every buyback tier of this collectible, past ones too, soonest end first. The price now is the `amountInUsdt` of the first tier whose `expiresAt` has not passed; a tier still applies at its `expiresAt`. A buyback signs the sum of those prices over its collectibles. If a tier ends before the buyback reaches Renaiss, the buyback returns 409 `GACHA_V3_BUYBACK_PRICE_CHANGED`: read the offers again and sign the new amount. The offer ends at the `expiresAt` of the last positive-amount `buybackTiers` item. required: - cardPackId - settlementId - tokenId - vendingMachineAddress - buybackTiers required: - offers '400': description: >- The request was refused before anything happened. See [error codes and recovery](/api-reference/gacha/list-buybacks#http-errors). content: application/json: schema: type: object properties: code: type: string enum: - WRONG_REQUEST_PARAMS message: type: string description: A short sentence about what went wrong. required: - code - message example: code: WRONG_REQUEST_PARAMS message: Bad request - invalid parameters '401': description: >- The builder key is missing or not accepted. See [error codes and recovery](/api-reference/gacha/list-buybacks#http-errors). content: application/json: schema: type: object properties: error: type: string description: A short sentence about what went wrong. code: type: string enum: - API_AUTH_MISSING_CREDENTIAL - API_AUTH_INVALID_CREDENTIAL required: - error - code example: error: Required authentication credential is missing code: API_AUTH_MISSING_CREDENTIAL '403': description: >- The builder key is not allowed to make this request. See [error codes and recovery](/api-reference/gacha/list-buybacks#http-errors). content: application/json: schema: type: object properties: error: type: string description: A short sentence about what went wrong. code: type: string enum: - API_AUTH_CREDENTIAL_NOT_ALLOWED - GACHA_V3_BUILDER_NOT_ACCEPTED_ON_PUBLIC_API required: - error - code example: error: Credential is not allowed by this policy code: API_AUTH_CREDENTIAL_NOT_ALLOWED '429': description: >- Too many requests with this builder key. See [error codes and recovery](/api-reference/gacha/list-buybacks#http-errors). content: application/json: schema: type: object properties: error: type: string description: A short sentence about what went wrong. code: type: string enum: - API_AUTH_RATE_LIMITED required: - error - code example: error: Authentication rate limit exceeded code: API_AUTH_RATE_LIMITED '500': description: >- A failure on our side. Retry later. See [error codes and recovery](/api-reference/gacha/list-buybacks#http-errors). content: application/json: schema: type: object properties: error: type: string description: A short sentence about what went wrong. code: type: string required: - error - code example: error: Internal server error code: FUNCTION_ERROR security: - builderAuth: [] components: securitySchemes: builderAuth: type: apiKey in: header name: x-builder-api-key description: >- Your approved builder API key. Keep it on your backend. Gacha and marketplace writes also require wallet action signatures. Redeem also needs a wallet access token, a Bearer token the API issues after the wallet signs a sign-in message. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.