> ## Documentation Index > Fetch the complete documentation index at: https://docs.byzantine.fi/llms.txt > Use this file to discover all available pages before exploring further. # Sign payload > Sign a payload allowing Byzantine to make, execute and sponsor the transaction. ## OpenAPI ````yaml /api-reference/openapi-integrator.json post /v1/submit/sign-payload-passkey openapi: 3.0.3 info: title: Byzantine Integrator API description: Byzantine REST API for integrators. license: name: '' version: 0.2.0 servers: - url: https://sandbox.api.byzantine.fi description: Sandbox security: [] tags: - name: API health description: Check API status. - name: Customer management description: Endpoints to create, update, and retrieve customer information. - name: Account management description: Endpoints to manage accounts, bank accounts, invitations, and user roles. - name: Products description: Endpoints to get data about products and vaults. - name: Transactions description: Endpoints to create and manage transactions. - name: OTP authentication description: Endpoints to initialize and manage user authentication with OTP. - name: Webhooks description: Integrator-managed outbound webhook subscriptions and delivery history. paths: /v1/submit/sign-payload-passkey: post: tags: - Transactions summary: Sign payload description: >- Sign a payload allowing Byzantine to make, execute and sponsor the transaction. operationId: sign_payload_passkey parameters: - name: X-Pubkey in: header description: >- Integrator's ECDSA public key (P-256 curve, compressed SEC1 format). Example: 0x038fedef7c12f93bbf342ad8943b7a825a3b41f61c9dc118b2c718efebabbf62fd required: true schema: type: string - name: X-Timestamp in: header description: >- Unix timestamp in seconds (UTC). Must be within tolerance window (1 minute) to prevent replay attacks. Example: 1760375826 required: true schema: type: string - name: X-Signature in: header description: >- ECDSA signature (DER-encoded, hex with 0x prefix). Signs the message: {timestamp}{METHOD}{path_and_query}{json_body}. Example: 0x3045022100... required: true schema: type: string - name: chain_id in: query description: Chain ID (1 for Ethereum, 8453 for Base) required: true schema: type: integer format: int32 minimum: 0 requestBody: description: The payload body details signed by the user - passkey auth content: application/json: schema: $ref: '#/components/schemas/SignPayloadRequestBodyPasskey' required: true responses: '200': description: Transaction sent successfully content: application/json: schema: $ref: '#/components/schemas/SendTransactionResponseBody' '400': description: Invalid chain ID security: - integrator_auth: [] components: schemas: SignPayloadRequestBodyPasskey: type: object required: - signedBody - transactionId - webAuthnStamp properties: signedBody: $ref: '#/components/schemas/SignedBody' transactionId: $ref: '#/components/schemas/Uuid' webAuthnStamp: type: string description: >- Cryptographically passkey signed (stamped). For more info, see [authentication methods](https://docs.byzantine.fi/api-reference/authentication-methods). SendTransactionResponseBody: type: object required: - transactionId - status properties: transactionId: $ref: '#/components/schemas/Uuid' status: $ref: '#/components/schemas/TransactionStatus' broadcastedAt: type: string format: date-time description: Exact timestamp when the transaction was broadcasted on-chain. example: '2025-11-19T21:16:02.894Z' nullable: true transactionHash: type: string description: >- The on-chain transaction hash. Available immediately after broadcast - poll RPC's `eth_getTransactionReceipt` to get the full receipt. nullable: true fiatDepositInstructions: allOf: - $ref: '#/components/schemas/SourceDepositInstructions' nullable: true destinationBankAccount: allOf: - $ref: '#/components/schemas/BankAccount' nullable: true SignedBody: oneOf: - $ref: '#/components/schemas/SignRawPayloadRequest' - $ref: '#/components/schemas/SignRawPayloadsRequest' description: >- Accepts either a single-payload or a multi-payload request Turnkey request Uuid: type: string format: uuid description: A UUID string example: 550e8400-e29b-41d4-a716-446655440000 TransactionStatus: type: string description: The current status of the transaction. enum: - created - waiting_for_funds - funds_in_transfer - funds_received - processing - completed - simulation_failed - reverted example: completed SourceDepositInstructions: type: object required: - currency - bankName - bankAddress - paymentRails - bankBeneficiaryName properties: currency: $ref: '#/components/schemas/Currency' expectedDepositAmount: allOf: - $ref: '#/components/schemas/Decimal' nullable: true bankName: type: string description: The name of the beneficiary bank. example: Lead Bank bankAddress: type: string description: The address of the beneficiary bank. example: 1801 Main St., Kansas City, MO 64108 paymentRails: type: array items: $ref: '#/components/schemas/PaymentRailVirtualAccount' bankBeneficiaryName: type: string description: >- The name of the beneficiary. Either first and last name, or a business name. example: John Smith bankBeneficiaryAddress: type: string description: The address of the beneficiary. example: 1234 Main St., Kansas City, MO 64108 bankAccountNumber: type: string description: In case of a USD deposit, the bank account number to deposit to. example: '1234567890' nullable: true bankRoutingNumber: type: string description: In case of a USD deposit, the ban routing number to deposit to. example: '87654321' nullable: true iban: type: string description: In case of a EUR deposit, the IBAN to deposit to. example: FR12345678901234567890 nullable: true bic: type: string description: In case of a EUR deposit, the BIC to deposit to. example: BICFR12345 nullable: true BankAccount: oneOf: - $ref: '#/components/schemas/BridgeGetIbanAccountDetails' - $ref: '#/components/schemas/BridgeGetAchAccountDetails' description: >- Bank account details where the funds will be transferred to (withdrawals only). SignRawPayloadRequest: type: object description: >- The object that needs to be signed by the end user to make a transaction. required: - type - timestampMs - organizationId - parameters properties: type: type: string description: Defaults to `ACTIVITY_TYPE_SIGN_RAW_PAYLOAD_V2` example: ACTIVITY_TYPE_SIGN_RAW_PAYLOAD_V2 timestampMs: type: string description: UNIX timestamp of the creation of the transaction. organizationId: type: string description: The account ID making the transaction. parameters: $ref: '#/components/schemas/SignRawPayloadParams' SignRawPayloadsRequest: type: object description: >- The object that needs to be signed by the end user to make a batch of transactions. required: - type - timestampMs - organizationId - parameters properties: type: type: string description: Defaults to `ACTIVITY_TYPE_SIGN_RAW_PAYLOADS`. example: ACTIVITY_TYPE_SIGN_RAW_PAYLOADS timestampMs: type: string description: UNIX timestamp of the creation of the transaction. organizationId: type: string description: The account ID making the transaction. parameters: $ref: '#/components/schemas/SignRawPayloadsParams' Currency: type: string enum: - usd - eur - usdc - eurc Decimal: type: string description: A high-precision decimal number represented as a string example: '123.456789' PaymentRailVirtualAccount: type: string enum: - achPush - pix - sepa - spei - wire BridgeGetIbanAccountDetails: type: object description: IBAN bank account informations required: - country - last4 properties: country: type: string description: >- The ISO 3166-1 (three-character) country code of the relevant country. See the full list of [countries](https://docs.byzantine.fi/api-reference/lists/countries). example: FRA last4: type: string description: Last 4 digits of the bank account number example: '0804' bic: type: string description: The Bank Identifier Code (BIC) that will be used to send the funds example: BICFR12345 nullable: true BridgeGetAchAccountDetails: type: object description: ACH bank account informations required: - routingNumber - last4 properties: routingNumber: type: string description: The bank routing number. example: '121000248' last4: type: string description: Last 4 digits of the bank account number. example: '1111' checkingOrSavings: allOf: - $ref: '#/components/schemas/CheckingOrSavings' nullable: true SignRawPayloadParams: type: object description: >- The parameters object containing the specific intent data for this transaction. required: - signWith - payload - encoding - hashFunction properties: signWith: type: string description: >- A Wallet account address, Private Key address, or Private Key identifier. payload: type: string description: Raw unsigned payload to be signed. encoding: type: string description: >- How the payload is encoded: `PAYLOAD_ENCODING_HEXADECIMAL` or `PAYLOAD_ENCODING_EIP7702_AUTHORIZATION` example: PAYLOAD_ENCODING_HEXADECIMAL hashFunction: type: string description: >- Rather Turnkey should hash the message or not: `HASH_FUNCTION_NO_OP` or `HASH_FUNCTION_KECCAK256` example: HASH_FUNCTION_NO_OP SignRawPayloadsParams: type: object description: >- The parameters object containing the specific intent data for this batch of transactions. required: - signWith - payloads - encoding - hashFunction properties: signWith: type: string description: >- A Wallet account address, Private Key address, or Private Key identifier. payloads: type: array items: type: string description: An array of raw unsigned payloads to be signed. encoding: type: string description: >- How the payload is encoded: `PAYLOAD_ENCODING_HEXADECIMAL` or `PAYLOAD_ENCODING_EIP7702_AUTHORIZATION` example: PAYLOAD_ENCODING_HEXADECIMAL hashFunction: type: string description: >- Rather Turnkey should hash the message or not: `HASH_FUNCTION_NO_OP` or `HASH_FUNCTION_KECCAK256` example: HASH_FUNCTION_NO_OP CheckingOrSavings: type: string enum: - checking - savings - unknown securitySchemes: integrator_auth: type: apiKey in: header name: X-Pubkey, X-Timestamp, X-Signature ````