generated: '2026-07-24' method: derived source: openapi/shift4-payment-api.yml summary: types: - apiKey - http api_key_in: - header schemes: - name: AccessToken type: apiKey in: header parameter: AccessToken description: "A security credential used to authenticate API requests and all [i4Go®](https://s4-myportal.s3.amazonaws.com/downloads/documentation/i4go/i4go%20technical%20reference%20guide.pdf)\ \ authorizeClient/preauthorizeClient requests. An Access Token is the alias for the merchant\ \ account and interface being used. \n\nExample:\n ```\n AccessToken: EA79FB05-3AA7-4500-AF9A-73F986FF2C1D\n\ \ ```" sources: - openapi/shift4-payment-api.yml - name: HMAC-SHA256 type: http scheme: hmac-sha256 description: "Authentication using HMAC-256 signatures as the authorization scheme.\n\nSent\ \ in the `Authorization` header in the following format:\n\n`Authorization`: **HMAC-SHA256**\ \ `Credential`={value}&`Signature`={value}\n\n| Argument | Description \ \ |\n|---------------|--------------------------------------------------|\n\ | HMAC-SHA256 | Authorization scheme. " sources: - openapi/shift4-payment-api.yml