> ## Documentation Index > Fetch the complete documentation index at: https://docs.gate.com/llms.txt > Use this file to discover all available pages before exploring further. # Preview Merchant Fee > Estimates transaction fee, revenue share, and settlement amount based on merchant information and order parameters. Gate Pay merchants only. ## Overview This page documents the `POST /payClearing/clearing/previewMerchantFee` endpoint. The full schema, parameters, and examples are rendered from the linked OpenAPI definition above. ## Notes * Authentication uses the standard GatePay signed headers. * This page documents the standard merchant endpoint. * Optional request body field `orderType` (0-address, 1-checkout, 2-static QR, 3-invoicing, 4-AI; fallback rate if omitted). * Optional header `X-GatePay-Sub-MerchantId` for institution sub-account; revenue share markup applies only when provided. * Response adds `institutionFeeAmount` (revenue share) and `settleAmount` (amount credited after deducting fee and revenue share). * Formula: `settlement amount = order amount − transaction fee − revenue share`. * For shared signing rules, see [/global/api-reference/version/100/en/common/securityAndSignature](/global/api-reference/version/100/en/common/securityAndSignature). ## OpenAPI ````yaml global/api-reference/version/100/en/openapi/preview-merchant-fee-openapi.json POST /payClearing/clearing/previewMerchantFee openapi: 3.1.0 info: title: GatePay API description: GatePay Payment Platform API - Estimate Merchant Fees license: name: MIT version: 1.0.0 servers: - url: https://openplatform.gateapi.io security: [] paths: /payClearing/clearing/previewMerchantFee: post: summary: Estimate Merchant Fees description: >- Estimates transaction fee, revenue share, and settlement amount based on merchant information and order parameters. Gate Pay merchants only. parameters: - $ref: '#/components/parameters/X-GatePay-Certificate-ClientId' - $ref: '#/components/parameters/X-GatePay-Signature' - $ref: '#/components/parameters/X-GatePay-Timestamp' - $ref: '#/components/parameters/X-GatePay-Nonce' - $ref: '#/components/parameters/X-GatePay-Sub-MerchantId' requestBody: description: Estimate merchant fee request parameters content: application/json: schema: $ref: '#/components/schemas/PreviewMerchantFeeRequest' examples: basicExample: summary: Basic Example value: orderCurrency: USDT accessMode: 0 scenario: 0 orderAmount: '100.00' required: true responses: '200': description: Estimation successful content: application/json: schema: $ref: '#/components/schemas/PreviewMerchantFeeResponse' examples: successResponse: summary: Success Response value: status: success code: '000000' errorMessage: '' data: merchantId: '123456789' merchantType: 1 accessMode: 0 orderCurrency: USDT orderAmount: 100 orderFee: 2.5 institutionFeeAmount: 2.5 settleAmount: 95 '400': description: Request parameter error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: invalidParams: summary: Invalid request parameters value: status: error code: '400001' errorMessage: Invalid request parameters data: null invalidSignature: summary: Invalid signature value: status: error code: '400002' errorMessage: Invalid signature data: null invalidApiKey: summary: API identity key not found or invalid value: status: error code: '400004' errorMessage: API identity key not found or invalid data: null invalidClientId: summary: INVALID_CLIENT_ID value: status: error code: '400005' errorMessage: INVALID_CLIENT_ID/Client ID error data: null unsupportedMediaType: summary: Unsupported media type value: status: error code: '400007' errorMessage: Unsupported media type data: null '500': description: Server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: feeServiceError: summary: Failed to call the fee calculation service value: status: error code: '503011007' errorMessage: Failed to call the fee calculation service data: null feeConfigEmpty: summary: Merchant fee configuration is empty value: status: error code: '503011008' errorMessage: Merchant fee configuration is empty data: null unknownError: summary: Unknown error value: status: error code: '503010999' errorMessage: Unknown error data: null components: parameters: X-GatePay-Certificate-ClientId: name: X-GatePay-Certificate-ClientId in: header required: true description: Merchant ID schema: type: string example: mZ96D37oKk-HrWJc X-GatePay-Signature: name: X-GatePay-Signature in: header required: true description: Signature schema: type: string example: >- 601d560c54d53412aca5901256f101e7078b5779f61f30bedfe9a5f0b92f049589952a151ea477371e4a99ac0e1c3cc8dec62654b3c6a1794ef981efe19232bc X-GatePay-Timestamp: name: X-GatePay-Timestamp in: header required: true description: >- Millisecond timestamp; the difference from server time must not exceed 30 seconds. schema: type: string example: '1726027137585' X-GatePay-Nonce: name: X-GatePay-Nonce in: header required: true description: Nonce schema: type: string example: '2290830087' X-GatePay-Sub-MerchantId: name: X-GatePay-Sub-MerchantId in: header required: false description: >- Sub-merchant UID for institution sub-account. Optional; revenue share (markup) is calculated only when this header is provided. schema: type: string example: '2124674730' schemas: PreviewMerchantFeeRequest: type: object required: - orderCurrency - accessMode - scenario - orderAmount properties: orderCurrency: type: string description: Order currency, e.g., USDT, USDC, etc. example: USDT accessMode: type: integer description: 'Integration mode: 0=Gate Pay, 1=Web3 payment' enum: - 0 - 1 example: 0 scenario: type: integer description: 'Transaction type (Scenario): 0=Collection' enum: - 0 example: 0 orderAmount: type: string format: decimal description: Order amount, must be greater than or equal to 0 example: '100.00' orderType: type: integer description: >- Order type. Optional values: 0-address payment, 1-checkout payment, 2-static QR code, 3-invoicing payment, 4-AI payment. If omitted, fallback rate applies. enum: - 0 - 1 - 2 - 3 - 4 example: 0 PreviewMerchantFeeResponse: type: object properties: status: type: string description: 'Response status: success/error' enum: - success - error example: success code: type: string description: Response code, 000000 indicates success example: '000000' errorMessage: type: string description: Error message, empty on success example: '' data: $ref: '#/components/schemas/PreviewMerchantFeeData' ErrorResponse: type: object properties: status: type: string description: Response status enum: - error example: error code: type: string description: Error code example: '400001' errorMessage: type: string description: Error message example: Invalid request parameters data: type: 'null' description: Null on error PreviewMerchantFeeData: type: object properties: merchantId: type: string description: Merchant ID example: '123456789' merchantType: type: integer description: 'Merchant type: 0=NORMAL_MERCHANT, 1=AGENT' enum: - 0 - 1 example: 1 accessMode: type: integer description: 'Integration mode: 0=Gate Pay, 1=Web3 payment' enum: - 0 - 1 example: 0 orderCurrency: type: string description: Order currency example: USDT orderAmount: type: number format: decimal description: Order amount example: 100 orderFee: type: number format: decimal description: Transaction fee, collected by the platform example: 2.5 institutionFeeAmount: type: number format: decimal description: Revenue share, the markup portion collected by the institution example: 0 settleAmount: type: number format: decimal description: >- Settlement amount credited to the merchant balance after deducting transaction fee and revenue share example: 97.5 ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.