diff --git a/ymt_v3/example_test.go b/ymt_v3/example_test.go
new file mode 100644
index 0000000..4bb00b7
--- /dev/null
+++ b/ymt_v3/example_test.go
@@ -0,0 +1,324 @@
+package ymt_v3
+
+import (
+	"encoding/json"
+	"fmt"
+	"testing"
+)
+
+// 测试参数（请替换为实际值）
+const (
+	testAppID      = "your_app_id"
+	testPrivateKey = `-----BEGIN PRIVATE KEY-----
+your_private_key_here
+-----END PRIVATE KEY-----`
+	testPublicKey = `-----BEGIN PUBLIC KEY-----
+your_public_key_here
+-----END PUBLIC KEY-----`
+	testKey        = "your_encryption_key_16"
+	testActivityNo = "your_activity_no"
+)
+
+func ExampleClient_KeyOrder() {
+	// 创建客户端
+	client, err := NewClient(&ClientConfig{
+		AppID:       testAppID,
+		PrivateKey:  testPrivateKey,
+		PublicKey:   testPublicKey,
+		Key:         testKey,
+		EncryptType: EncryptTypeAES,
+		Env:         EnvTest,
+	})
+	if err != nil {
+		fmt.Printf("创建客户端失败: %v\n", err)
+		return
+	}
+
+	// 获取券码
+	resp, err := client.KeyOrder(&KeyOrderRequest{
+		OutBizNo:   "order_001",
+		ActivityNo: testActivityNo,
+		Account:    "18666666666",
+		NotifyURL:  "https://notify.example.com/openapi",
+	})
+	if err != nil {
+		fmt.Printf("获取券码失败: %v\n", err)
+		return
+	}
+
+	fmt.Printf("交易号: %s\n", resp.TradeNo)
+	fmt.Printf("卡密: %s\n", resp.Key)
+	fmt.Printf("状态: %d\n", resp.Status)
+
+	// Output:
+	// 交易号: 7251449503000383488
+	// 卡密: aZKdU9BymzR6qGRzJM
+	// 状态: 1
+}
+
+func ExampleClient_KeyQuery() {
+	client, _ := NewClient(&ClientConfig{
+		AppID:       testAppID,
+		PrivateKey:  testPrivateKey,
+		PublicKey:   testPublicKey,
+		Key:         testKey,
+		EncryptType: EncryptTypeAES,
+		Env:         EnvTest,
+	})
+
+	// 按外部业务号查询
+	resp, err := client.KeyQuery(&KeyQueryRequest{
+		OutBizNo: "order_001",
+	})
+	if err != nil {
+		fmt.Printf("查询失败: %v\n", err)
+		return
+	}
+
+	fmt.Printf("交易号: %s\n", resp.TradeNo)
+	fmt.Printf("状态: %d\n", resp.Status)
+}
+
+func ExampleClient_KeyDiscard() {
+	client, _ := NewClient(&ClientConfig{
+		AppID:       testAppID,
+		PrivateKey:  testPrivateKey,
+		PublicKey:   testPublicKey,
+		Key:         testKey,
+		EncryptType: EncryptTypeAES,
+		Env:         EnvTest,
+	})
+
+	// 按交易号作废
+	resp, err := client.KeyDiscard(&KeyDiscardRequest{
+		TradeNo: "7251449503000383488",
+	})
+	if err != nil {
+		fmt.Printf("作废失败: %v\n", err)
+		return
+	}
+
+	fmt.Printf("交易号: %s\n", resp.TradeNo)
+	fmt.Printf("状态: %d\n", resp.Status)
+}
+
+func ExampleClient_BatchOrder() {
+	client, _ := NewClient(&ClientConfig{
+		AppID:       testAppID,
+		PrivateKey:  testPrivateKey,
+		PublicKey:   testPublicKey,
+		Key:         testKey,
+		EncryptType: EncryptTypeAES,
+		Env:         EnvTest,
+	})
+
+	// 批量发卡
+	resp, err := client.BatchOrder(&BatchOrderRequest{
+		OutBizNo:   "batch_001",
+		ActivityNo: testActivityNo,
+		Number:     100,
+		NotifyURL:  "https://notify.example.com/openapi",
+	})
+	if err != nil {
+		fmt.Printf("批量发卡失败: %v\n", err)
+		return
+	}
+
+	fmt.Printf("交易号: %s\n", resp.TradeNo)
+	fmt.Printf("状态: %s\n", resp.Status)
+}
+
+func ExampleClient_BatchQuery() {
+	client, _ := NewClient(&ClientConfig{
+		AppID:       testAppID,
+		PrivateKey:  testPrivateKey,
+		PublicKey:   testPublicKey,
+		Key:         testKey,
+		EncryptType: EncryptTypeAES,
+		Env:         EnvTest,
+	})
+
+	// 查询批量任务
+	resp, err := client.BatchQuery(&BatchQueryRequest{
+		TradeNo: "7251449503000383499",
+	})
+	if err != nil {
+		fmt.Printf("查询失败: %v\n", err)
+		return
+	}
+
+	fmt.Printf("状态: %s\n", resp.Status)
+	if resp.DownloadURL != "" {
+		fmt.Printf("下载地址: %s\n", resp.DownloadURL)
+	}
+}
+
+func TestMarshalWithoutZero(t *testing.T) {
+	req := KeyOrderRequest{
+		OutBizNo:   "order_001",
+		ActivityNo: "ACT20260622001",
+		// Account和NotifyURL为空，应该被去掉
+	}
+
+	result, err := marshalWithoutZero(req)
+	if err != nil {
+		t.Fatalf("marshalWithoutZero失败: %v", err)
+	}
+
+	expected := `{"activity_no":"ACT20260622001","out_biz_no":"order_001"}`
+	if result != expected {
+		t.Errorf("期望 %s, 得到 %s", expected, result)
+	}
+}
+
+func TestBuildSignStr(t *testing.T) {
+	appID := "123456"
+	timestamp := "2026-06-22 15:30:00"
+	ciphertext := "encrypted_data"
+
+	signStr := BuildSignStr(appID, timestamp, ciphertext)
+	expected := "1234562026-06-22 15:30:00encrypted_data"
+	if signStr != expected {
+		t.Errorf("期望 %s, 得到 %s", expected, signStr)
+	}
+}
+
+func TestGenerateTimestamp(t *testing.T) {
+	ts := GenerateTimestamp()
+	// 验证格式 yyyy-MM-dd HH:mm:ss
+	if len(ts) != 19 {
+		t.Errorf("时间戳格式错误: %s", ts)
+	}
+}
+
+func TestEncryptDecryptAES(t *testing.T) {
+	key := []byte("1234567890123456") // 16字节
+	plaintext := `{"out_biz_no":"order_001","activity_no":"ACT001"}`
+
+	ciphertext, err := AESECBEncrypt([]byte(plaintext), key)
+	if err != nil {
+		t.Fatalf("加密失败: %v", err)
+	}
+
+	decrypted, err := AESECBDecrypt(ciphertext, key)
+	if err != nil {
+		t.Fatalf("解密失败: %v", err)
+	}
+
+	if string(decrypted) != plaintext {
+		t.Errorf("解密结果不匹配: 期望 %s, 得到 %s", plaintext, string(decrypted))
+	}
+}
+
+func TestEncryptDecryptSM4(t *testing.T) {
+	key := []byte("1234567890123456") // 16字节
+	plaintext := `{"out_biz_no":"order_001","activity_no":"ACT001"}`
+
+	ciphertext, err := SM4CBCEncrypt([]byte(plaintext), key)
+	if err != nil {
+		t.Fatalf("SM4加密失败: %v", err)
+	}
+
+	decrypted, err := SM4CBCDecrypt(ciphertext, key)
+	if err != nil {
+		t.Fatalf("SM4解密失败: %v", err)
+	}
+
+	if string(decrypted) != plaintext {
+		t.Errorf("SM4解密结果不匹配: 期望 %s, 得到 %s", plaintext, string(decrypted))
+	}
+}
+
+func TestEncryptBizParams(t *testing.T) {
+	key := []byte("1234567890123456")
+	req := KeyOrderRequest{
+		OutBizNo:   "order_001",
+		ActivityNo: "ACT20260622001",
+	}
+
+	ciphertext, err := EncryptBizParams(req, key, EncryptTypeAES)
+	if err != nil {
+		t.Fatalf("加密业务参数失败: %v", err)
+	}
+
+	if ciphertext == "" {
+		t.Fatal("加密结果为空")
+	}
+
+	// 验证可以解密
+	decrypted, err := DecryptBizParams(ciphertext, key, EncryptTypeAES)
+	if err != nil {
+		t.Fatalf("解密失败: %v", err)
+	}
+
+	var result KeyOrderRequest
+	if err := json.Unmarshal(decrypted, &result); err != nil {
+		t.Fatalf("解析失败: %v", err)
+	}
+
+	if result.OutBizNo != "order_001" {
+		t.Errorf("OutBizNo不匹配: 期望 order_001, 得到 %s", result.OutBizNo)
+	}
+}
+
+func TestNewClient(t *testing.T) {
+	_, err := NewClient(&ClientConfig{
+		AppID:       testAppID,
+		PrivateKey:  testPrivateKey,
+		PublicKey:   testPublicKey,
+		Key:         testKey,
+		EncryptType: EncryptTypeAES,
+		Env:         EnvTest,
+	})
+	if err != nil {
+		t.Fatalf("创建客户端失败: %v", err)
+	}
+}
+
+func TestNewClientMissingFields(t *testing.T) {
+	tests := []struct {
+		name    string
+		config  *ClientConfig
+		wantErr bool
+	}{
+		{"空AppID", &ClientConfig{PrivateKey: "pk", PublicKey: "pub", Key: "key"}, true},
+		{"空PrivateKey", &ClientConfig{AppID: "app", PublicKey: "pub", Key: "key"}, true},
+		{"空PublicKey", &ClientConfig{AppID: "app", PrivateKey: "pk", Key: "key"}, true},
+		{"空Key", &ClientConfig{AppID: "app", PrivateKey: "pk", PublicKey: "pub"}, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := NewClient(tt.config)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("NewClient() error = %v, wantErr = %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func TestAPIError(t *testing.T) {
+	err := NewAPIError(401, "Signature verification failed", "INVALID_SIGNATURE")
+	if err.Code != 401 {
+		t.Errorf("Code不匹配: 期望 401, 得到 %d", err.Code)
+	}
+	if err.Message != "Signature verification failed" {
+		t.Errorf("Message不匹配")
+	}
+	if err.Reason != "INVALID_SIGNATURE" {
+		t.Errorf("Reason不匹配")
+	}
+	if err.Error() != "API error: code=401, message=Signature verification failed, reason=INVALID_SIGNATURE" {
+		t.Errorf("Error()不匹配: %s", err.Error())
+	}
+	if err.IsSuccess() {
+		t.Error("401应该不是成功")
+	}
+}
+
+func TestSDKError(t *testing.T) {
+	err := NewSDKError("测试错误", nil)
+	if err.Error() != "SDK error: 测试错误" {
+		t.Errorf("Error()不匹配: %s", err.Error())
+	}
+}
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