> ## Documentation Index > Fetch the complete documentation index at: https://docs.spritz.finance/llms.txt > Use this file to discover all available pages before exploring further. # Get transaction params for a quote > Returns transaction parameters for a `sign_transaction` quote. Use these to construct, sign, and submit the on-chain transaction. Returns either EVM calldata or a serialized Solana transaction depending on the quote's chain. ## OpenAPI ````yaml https://platform.spritz.finance/openapi.json post /v1/off-ramp-quotes/{quoteId}/transaction openapi: 3.0.3 info: title: Spritz Finance API version: 1.0.0 description: API for the Spritz Finance platform with RFC 9457 error handling servers: - url: https://platform.spritz.finance description: Production - url: https://sandbox.spritz.finance description: Sandbox security: [] tags: - name: Users description: User management endpoints - name: Bank Accounts description: Manage bank accounts for off-ramp destinations - name: Bills description: Manage bill pay accounts - name: Cards description: Spritz-issued debit cards - name: Auto-Ramp Accounts description: Virtual bank accounts that automatically convert fiat deposits to crypto - name: Spritz App description: >- Endpoints used by the Spritz app and internal SDKs. Excluded from the public partner spec. paths: /v1/off-ramp-quotes/{quoteId}/transaction: post: tags: - Off-Ramp Quotes summary: Get transaction params for a quote description: >- Returns transaction parameters for a `sign_transaction` quote. Use these to construct, sign, and submit the on-chain transaction. Returns either EVM calldata or a serialized Solana transaction depending on the quote's chain. operationId: postV1Off-ramp-quotesByQuoteIdTransaction parameters: - name: quoteId in: path required: true schema: description: The quote ID type: string example: quote_abc123 requestBody: required: true content: application/json: schema: type: object properties: senderAddress: description: >- Wallet address that will sign the transaction. Required for Solana. type: string example: '0x742d35Cc6634C0532925a3b844Bc9e7595f2bD18' feePayer: description: >- Address that pays transaction fees. Solana only — defaults to senderAddress if omitted. type: string example: 5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d application/x-www-form-urlencoded: schema: type: object properties: senderAddress: description: >- Wallet address that will sign the transaction. Required for Solana. type: string example: '0x742d35Cc6634C0532925a3b844Bc9e7595f2bD18' feePayer: description: >- Address that pays transaction fees. Solana only — defaults to senderAddress if omitted. type: string example: 5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d multipart/form-data: schema: type: object properties: senderAddress: description: >- Wallet address that will sign the transaction. Required for Solana. type: string example: '0x742d35Cc6634C0532925a3b844Bc9e7595f2bD18' feePayer: description: >- Address that pays transaction fees. Solana only — defaults to senderAddress if omitted. type: string example: 5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d responses: '200': description: Response for status 200 content: application/json: schema: anyOf: - description: EVM transaction parameters type: object properties: type: type: string enum: - evm chain: description: Blockchain network type: string example: ethereum inputToken: description: >- Token address the user sends (contract address on EVM, mint address on Solana) type: string example: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48' outputToken: description: >- Token address received by the payment contract. Same as inputToken for direct payments, different for swap paths. type: string example: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48' requiredTokenInput: description: >- Exact amount of inputToken to send, in smallest unit (e.g. 6 decimals for USDC) type: string example: '100000000' contractAddress: description: >- Smart contract address — use as the `to` field when constructing the transaction type: string example: '0xbF7Abc15f00a8C2d6b13A952c58d12b7c194A8D0' calldata: description: ABI-encoded calldata for the contract call type: string example: 0xd71d9632... method: description: Contract method being called type: string example: payWithToken value: description: >- Native token value in wei to send with the transaction (null for ERC-20 payments) type: string nullable: true example: '0' required: - type - chain - inputToken - outputToken - requiredTokenInput - contractAddress - calldata - method - value - description: Solana transaction parameters type: object properties: type: type: string enum: - solana chain: description: Blockchain network type: string example: ethereum inputToken: description: >- Token address the user sends (contract address on EVM, mint address on Solana) type: string example: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48' outputToken: description: >- Token address received by the payment contract. Same as inputToken for direct payments, different for swap paths. type: string example: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48' requiredTokenInput: description: >- Exact amount of inputToken to send, in smallest unit (e.g. 6 decimals for USDC) type: string example: '100000000' recipientAddress: description: Account address that receives the funds type: string example: 5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d transactionSerialized: description: >- Base64-encoded VersionedTransaction ready to sign and submit type: string example: base64EncodedTransaction... required: - type - chain - inputToken - outputToken - requiredTokenInput - recipientAddress - transactionSerialized '401': description: Response for status 401 content: application/json: schema: type: object properties: type: default: about:blank description: A URI reference that identifies the problem type type: string example: urn:problem-type:auth:unauthorized title: description: A short, human-readable summary of the problem type type: string example: Unauthorized status: description: The HTTP status code type: number example: 401 detail: description: A human-readable explanation specific to this occurrence type: string example: Bearer token required instance: description: A URI reference that identifies the specific occurrence type: string realm: description: The authentication realm type: string example: API scope: description: The required scope for this resource type: string example: read:users required: - title - status additionalProperties: false '404': description: Response for status 404 content: application/json: schema: type: object properties: type: default: about:blank description: A URI reference that identifies the problem type type: string title: description: A short, human-readable summary of the problem type type: string status: description: The HTTP status code type: number example: 404 detail: description: A human-readable explanation specific to this occurrence type: string instance: description: A URI reference that identifies the specific occurrence type: string resourceType: description: The type of resource that was not found type: string example: user resourceId: description: The identifier of the resource that was not found type: string required: - title - status - resourceType - resourceId additionalProperties: false '500': description: Response for status 500 content: application/json: schema: type: object properties: type: default: about:blank description: A URI reference that identifies the problem type type: string example: urn:problem-type:auth:unauthorized title: description: A short, human-readable summary of the problem type type: string example: Unauthorized status: description: The HTTP status code type: number example: 400 detail: description: A human-readable explanation specific to this occurrence type: string instance: description: A URI reference that identifies the specific occurrence type: string example: /errors/1234567890 code: description: >- Machine-readable cause, present when exactly one thing failed. Branch on this, never on `detail`, which is human-facing copy and may change. For deposit limits the vocabulary matches the `reason` values the limits API returns pre-flight. type: string example: transaction_limit field: description: The offending request field, present alongside `code`. type: string example: amountUsd retryable: description: >- Whether retrying the same request later may succeed without changing its inputs. type: boolean example: true required: - title - status additionalProperties: false security: - bearerAuth: [] - integratorJwt: [] - hmacAuth: [] integratorKey: [] timestamp: [] components: securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT description: Cognito JWT token for regular user authentication integratorJwt: type: http scheme: bearer bearerFormat: JWT description: >- Integrator JWT token (prefix: spr_) for frontend integrator authentication. Obtained via token exchange endpoint. hmacAuth: type: apiKey in: header name: X-Signature description: >- HMAC signature authentication for backend integrators. **Required Headers:** - X-Integrator-Key: Integrator API key (format: int_...) - X-Signature: HMAC signature (format: sha256={hex}) - X-Timestamp: Unix timestamp in milliseconds - Authorization: Bearer {user-api-key} **Signature Algorithm:** HMAC-SHA256 **Signature Format:** {timestamp}.{METHOD}.{path}.{bodyHash} - timestamp: Unix timestamp in milliseconds - METHOD: HTTP method in UPPERCASE (GET, POST, etc.) - path: Request path (e.g., /v1/transactions) - bodyHash: SHA256 hex digest of request body (empty string if no body) **Timestamp Tolerance:** ±5 minutes (300 seconds) **Example:** For POST /v1/transactions with body {"amount":100} and timestamp 1234567890000: Payload: 1234567890000.POST./v1/transactions.{sha256(body)} Signature: sha256=abc123... integratorKey: type: apiKey in: header name: X-Integrator-Key description: 'Integrator API key (format: int_...) used with HMAC authentication' timestamp: type: apiKey in: header name: X-Timestamp description: >- Unix timestamp in milliseconds for replay attack prevention. Must be within 5 minutes of server time. ````