GoPay SDK

To use WeChat v3 APIs, initialize a client using wechat.NewClientV3. You must provide the Merchant ID (mchid), the certificate serial number (serialNo), the apiV3Key, and the content of your private key (apiclient_key.pem).

Automatic Signature Verification Options:

• Recommended for new users: Use AutoVerifySignByPublicKey by providing the WeChat Pay public key content and the Public Key ID (must include the PUB_KEY_ID_ prefix).
• Alternative: Use AutoVerifySign() to automatically fetch and periodically update WeChat platform certificates.

Note: WeChat v3 does not support sandbox environments; use a 0.01 CNY transaction for testing.

To use the PayPal SDK, initialize a new client using paypal.NewClient with your Clientid and Secret. You can also configure the maximum HTTP response body size and enable debug logging.

import (
    "github.com/go-pay/gopay/paypal"
    "github.com/go-pay/xlog"
)

// Initialize PayPal payment client
client, err := paypal.NewClient(Clientid, Secret, false)
if err != nil {
    xlog.Error(err)
    return
}

// Custom configuration for HTTP response body size (default is 10MB)
client.SetBodySize()

// Enable debug mode to output logs (default is off)
client.DebugSwitch = gopay.DebugOn

The Saobei Payment 2.0 interface provides methods for processing payments, querying statuses, and handling refunds. For specific implementation details and usage examples, refer to the gopay/saobei/pay_test.go file in the repository.

Available methods on the client:

• client.MiniPay(): For Mini Program payments (requires a valid account for testing).
• client.BarcodePay(): For barcode payment processing.
• client.Query(): To query the status of a payment.
• client.Refund(): To submit a refund application.
• client.QueryRefund(): To query the status of a refund order.

When WeChat sends an asynchronous notification (webhook), you must parse the request body and verify the signature to ensure authenticity.

1. Parse: Use wechat.ParseNotifyToBodyMap(req) to convert the *http.Request into a BodyMap. For refund notifications, use wechat.ParseRefundNotify(req).
2. Verify: Use wechat.VerifySign(apiKey, signType, bean) where bean is the parsed BodyMap or response struct.
3. Refund Decryption: If processing a refund notification, the req_info field is encrypted. Use wechat.DecryptRefundNotifyReqInfo(reqInfo, apiKey) to decrypt it.
4. Response: Always return a valid XML response to WeChat to acknowledge receipt. Use rsp.ToXmlString().

Note: http.Request.Body can only be read once. If you need to debug or read it multiple times, handle body reuse manually.

To use Alipay V3, initialize a client using alipay.NewClientV3. You must provide your appid, your application privateKey (supports PKCS1 and PKCS8), and a boolean isProd to indicate if you are in a production environment. You must also load your certificates using SetCert.

Available configuration methods:

• SetAppAuthToken(token string): Sets the authorization token.
• SetBodySize(): Customizes the HTTP response body size (default is 10MB).
• SetRequestIdFunc(): Sets a custom method for generating RequestId.
• SetAESKey(key string): Sets the biz_content encryption key (currently unavailable).
• DebugSwitch: Set to gopay.DebugOn to enable debug logging.

Starting from v1.5.119, TLS certificate verification is enabled by default to prevent MITM attacks. For sandbox environments or scenarios using self-signed certificates, you must manually inject an xhttp.Client that skips verification using SetHttpClient. This is supported for WeChat, Alipay, Douyin, PayPal, QQ, Allinpay, Lakala, and Saobei.

import (
    "crypto/tls"
    "github.com/go-pay/gopay/pkg/xhttp"
)

hc := xhttp.NewClient().SetHttpTLSConfig(&tls.Config{InsecureSkipVerify: true})
client.SetHttpClient(hc) // wechat / alipay / douyin / paypal / qq / allinpay / lakala / saobei 均支持

Saobei provides specialized interfaces for managing funds and enterprise wallet distribution (CBK).

• Funds Interface: For managing merchant funds, refer to the examples in gopay/saobei/merchant_test.go.
• CBK Enterprise Wallet Distribution: For enterprise wallet splitting/distribution, refer to the examples in gopay/saobei/account_test.go.

To use WeChat v2 APIs, initialize a client using wechat.NewClient. You must provide the appId, mchId (Merchant ID), apiKey, and a boolean isProd to indicate if you are in a production environment.

Important Notes:

• Use isProd = false for sandbox testing. Use isProd = true for real payments.
• For certificates, you can either provide both apiclient_cert.pem and apiclient_key.pem OR a single apiclient_cert.p12 file.
• You can enable debug mode via client.DebugSwitch = gopay.DebugOn to output request logs.

Install the GoPay SDK using the standard Go get command:

go get github.com/go-pay/gopay