> ## 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. # Submit a buyback for polling > Each accepted submission creates a new request. Poll `GET /v2/gacha/buyback/status` with its `requestId` for the outcome. 1. **Sign.** Have the seller sign `BuybackUserAuthorization` for settlement IDs from the same pack. Submit the same body and builder key used by [Settle a buyback](https://docs.renaiss.xyz/api-reference/gacha/settle-buyback.md). An ID from another pack can return HTTP `404` with `EOA_PURCHASE_REJECTED`. 2. **Track.** Save `requestId` from HTTP `202`. [Check buyback status](https://docs.renaiss.xyz/api-reference/gacha/get-buyback-status.md) about once per second until `COMPLETED` or `FAILED`. Each submission creates a separate request. 3. **Handle a failure.** A failed request carries the same error code as a direct settlement. For `OP_WALLET_BUSY`, retry with the same signature. For other failures, refresh the offers and request a new signature. ## Request Builder key and wallet signature ## Response HTTP `202` returns `status: "PENDING"`, `error: null` and a new `requestId`. Use [Get buyback status](https://docs.renaiss.xyz/api-reference/gacha/get-buyback-status.md) for settlement failures. ## 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` | `API_AUTH_INVALID_INPUT` | `error` | `Request body is too large` The request body exceeds 16 KiB. Send a smaller body. | | `400` | `EOA_PURCHASE_REJECTED` | `error` | `SAFE addresses are not supported by v2` The wallet cannot be used for this buyback. Use another wallet. | | `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. | | `400` | No code | `text/plain` | `Malformed JSON in request body` | | `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` | `API_AUTH_INVALID_ACTION` | `error` | `Invalid wallet action proof` The signature was not accepted for the wallet and the signed data, or the buyback window has closed. Read the offers again and sign the new data. For a contract wallet, its `isValidSignature` must return `0x1626ba7e` for the EIP-712 digest of the signed data. | | `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. | | `404` | `EOA_PURCHASE_REJECTED` | `error` | `One or more builder draws were not found` `Pack not found` One or more of the collectibles were not pulled by this wallet under your builder key, or the pack was not found. Check the pack id and the settlement ids from `GET /v2/gacha/buyback/offers`. | | `404` | Other code | `error` | Read the returned `error` string. | | `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` The signature could not be checked because the chain could not be read. Retry the request. | | `500` | `FUNCTION_ERROR` | `error` | `Internal server error` | | `500` | Other code | `error` | `Internal server error` | ## OpenAPI ````yaml api-reference/openapi.json POST /v2/gacha/buyback/request 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/request: post: tags: - Gacha v2 summary: Submit a signed buyback and poll its requestId description: >- Each accepted submission creates a new request. Poll `GET /v2/gacha/buyback/status` with its `requestId` for the outcome. requestBody: required: true content: application/json: schema: type: object properties: buyerWalletAddress: type: string cardPackId: type: string format: uuid buybackAuth: type: object properties: buybackIds: type: array items: type: string minItems: 1 maxItems: 10 token: type: string amount: type: string pattern: ^\d+$ required: - buybackIds - token - amount userSignature: type: string required: - buyerWalletAddress - cardPackId - buybackAuth - userSignature additionalProperties: false responses: '202': description: >- Each accepted submission creates a new request. Poll `GET /v2/gacha/buyback/status` with its `requestId` for the outcome. content: application/json: schema: type: object properties: requestId: type: string format: uuid status: type: string enum: - PENDING buyerWalletAddress: type: string description: >- 20-byte, 0x-prefixed wallet or contract address. Use lowercase or a valid checksum. cardPackId: type: string format: uuid settlementIds: type: array items: type: string description: >- 32 bytes encoded as 0x followed by 64 hexadecimal digits. txHash: type: 'null' totalAmountInUsdt: type: 'null' itemCount: type: 'null' error: type: 'null' required: - requestId - status - buyerWalletAddress - cardPackId - settlementIds - txHash - totalAmountInUsdt - itemCount - error examples: PENDING: summary: The buyback is in progress. value: requestId: b81d0f7e-2c4a-4d6b-8e13-5a9c7d1f3b20 buyerWalletAddress: '0x4f2a9c1e7b3d58a60c9e1f2b3d4a5c6e7f8091a2' cardPackId: 3f6c2a1e-8b4d-4c7a-9e21-5d0b7a6c4f13 settlementIds: - >- 0x2222222222222222222222222222222222222222222222222222222222222222 status: PENDING txHash: null totalAmountInUsdt: null itemCount: null error: null '400': description: >- The request was refused before anything happened. See [error codes and recovery](/api-reference/gacha/submit-buyback#http-errors). content: text/plain: schema: type: string example: Malformed JSON in request body application/json: schema: anyOf: - type: object properties: error: type: string description: A short sentence about what went wrong. code: type: string enum: - API_AUTH_INVALID_INPUT - EOA_PURCHASE_REJECTED required: - error - code - 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/submit-buyback#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 request is refused. See [error codes and recovery](/api-reference/gacha/submit-buyback#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_INVALID_ACTION - API_AUTH_CREDENTIAL_NOT_ALLOWED - GACHA_V3_BUILDER_NOT_ACCEPTED_ON_PUBLIC_API required: - error - code example: error: Invalid wallet action proof code: API_AUTH_INVALID_ACTION '404': description: >- A collectible or the pack was not found. - Other codes can appear. Read `GET /v2/gacha/buyback/offers` before you send the request again. See [error codes and recovery](/api-reference/gacha/submit-buyback#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: One or more builder draws were not found code: EOA_PURCHASE_REJECTED '429': description: >- Too many requests with this builder key. See [error codes and recovery](/api-reference/gacha/submit-buyback#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 before the buyback was accepted. Nothing was sent. Retry later. See [error codes and recovery](/api-reference/gacha/submit-buyback#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.