PayPal REST API捕获订单未返回exchange_rate的原因咨询

我已搭建PayPal Advanced Checkout沙箱环境，使用以下API调用捕获订单：

/v2/checkout/orders/{{order_id}}/capture

创建订单时的交易详情 #

{    
    "intent": "CAPTURE",    
    "payer": {        
        "address": {            
            "admin_area_2": "Downton",            
            "postal_code": "SP5",            
            "country_code": "GB"        
        }    
    },    
    "purchase_units": [        
        {            
            "description": "Test Item",            
            "custom_id": "12345",            
            "soft_descriptor": "Purchase Descriptior",            
            "amount": {                
                "currency_code": "USD",                
                "value": "58.80",                
                "breakdown": {                    
                    "item_total": {                        
                        "currency_code": "USD",                        
                        "value": "49.00"                    
                    },                    
                    "tax_total": {                        
                        "currency_code": "USD",                        
                        "value": "9.80"                    
                    }                
                }            
            },            
            "items": [                
                {                    
                    "name": "Test Item",                    
                    "unit_amount": {                        
                        "currency_code": "USD",                        
                        "value": "49.00"                    
                    },                    
                    "tax": {                        
                        "currency_code": "USD",                        
                        "value": "9.80"                    
                    },                    
                    "quantity": 1,                    
                    "category": "PHYSICAL_GOODS"                
                }            
            ],            
            "shipping": {}        
        }    
    ]
}

订单捕获响应 #

{    
    "id": "4FS9138999682320N",    
    "status": "COMPLETED",    
    "payment_source": {        
        "paypal": {            
            "email_address": "sb-bdd43g21513704@personal.example.com",            
            "account_id": "V7ZN4NEJRLGZA",            
            "name": {                
                "given_name": "John",                
                "surname": "Doe"            
            },            
            "address": {                
                "country_code": "GB"            
            }        
        }    
    },    
    "purchase_units": [        
        {            
            "reference_id": "default",            
            "shipping": {                
                "name": {                    
                    "full_name": "John Doe"                
                },                
                "address": {                    
                    "address_line_1": "Whittaker House",                    
                    "address_line_2": "2 Whittaker Avenue",                    
                    "admin_area_2": "Richmond",                    
                    "admin_area_1": "Surrey",                    
                    "postal_code": "TW9 1EH",                    
                    "country_code": "GB"                
                }            
            },            
            "payments": {                
                "captures": [                    
                    {                        
                        "id": "40V95236PS9814847",                        
                        "status": "COMPLETED",                        
                        "amount": {                            
                            "currency_code": "USD",                            
                            "value": "58.80"                        
                        },                        
                        "final_capture": true,                        
                        "seller_protection": {                            
                            "status": "ELIGIBLE",                            
                            "dispute_categories": [                                
                                "ITEM_NOT_RECEIVED",                                
                                "UNAUTHORIZED_TRANSACTION"                            
                            ]                        
                        },                        
                        "seller_receivable_breakdown": {                            
                            "gross_amount": {                                
                                "currency_code": "USD",                                
                                "value": "58.80"                            
                            },                            
                            "paypal_fee": {                                
                                "currency_code": "USD",                                
                                "value": "2.30"                            
                            },                            
                            "net_amount": {                                
                                "currency_code": "USD",                                
                                "value": "56.50"                            
                            }                        
                        },                        
                        "custom_id": "12345",                        
                        "links": [                            
                            {                                
                                "href": "https://api.sandbox.paypal.com/v2/payments/captures/40V95236PS9814847",                                
                                "rel": "self",                                
                                "method": "GET"                            
                            },                            
                            {                                
                                "href": "https://api.sandbox.paypal.com/v2/payments/captures/40V95236PS9814847/refund",                                
                                "rel": "refund",                                
                                "method": "POST"                            
                            },                            
                            {                                
                                "href": "https://api.sandbox.paypal.com/v2/checkout/orders/4FS9138999682320N",                                
                                "rel": "up",                                
                                "method": "GET"                            
                            }                        
                        ],                        
                        "create_time": "2022-10-31T16:42:07Z",                        
                        "update_time": "2022-10-31T16:42:07Z"                    
                    }                
                ]            
            }        
        }    
    ],    
    "payer": {        
        "name": {            
            "given_name": "John",            
            "surname": "Doe"        
        },        
        "email_address": "sb-bdd43g21513704@personal.example.com",        
        "payer_id": "V7ZN4NEJRLGZA",        
        "address": {            
            "country_code": "GB"        
        }    
    },    
    "links": [        
        {            
            "href": "https://api.sandbox.paypal.com/v2/checkout/orders/4FS9138999682320N",            
            "rel": "self",            
            "method": "GET"        
        }    
    ]
}

我收到了状态为COMPLETED的响应，但尽管付款方币种与收款方币种不同，响应中却未返回exchange_rate字段。请问原因是什么？

回答 #

出现这种情况主要有以下几个可能的原因：

• 付款方未发生实际货币兑换
  虽然付款方地址归属英国，但如果其PayPal账户默认币种为USD，或者付款时选择了用USD余额、绑定的USD支付方式完成交易，全程没有涉及币种转换，自然不会返回exchange_rate字段。

• 沙箱环境的特殊逻辑限制
  PayPal沙箱环境的货币兑换规则和生产环境存在差异，部分跨币种交易场景下可能不会返回汇率信息。可以尝试给沙箱付款方账户设置仅持有GBP余额，再发起支付测试，观察是否会返回该字段。

• API字段的触发条件
  根据PayPal的API规范，exchange_rate字段仅在实际发生货币兑换操作的场景下才会返回。如果交易的付款、收款环节全程使用同一币种，该字段不会出现在响应结果中。

内容的提问来源于stack exchange，提问作者Henry-95