set default devicemanager endpoint as /dm/execute. As stated in VCHASNO docs.

api/client.go

@@ -1,11 +1,17 @@
 package api
 
-import "resty.dev/v3"
+import (
+	"crypto/tls"
+
+	"resty.dev/v3"
+)
 
 type Client struct {
 	token          string
+	device         string
 	resty          *resty.Client
 	apiBaseURL     string
+	fiscalEndpoint string
 }
 
 func NewClient(token string) *Client {
@@ -13,5 +19,27 @@ func NewClient(token string) *Client {
 		token:          token,
 		resty:          resty.New(),
 		apiBaseURL:     "https://kasa.vchasno.ua/api/v3",
+		fiscalEndpoint: "/fiscal/execute",
+	}
+}
+
+func NewDMClient(token, dmURL, device string) *Client {
+	restyClient := resty.New()
+	restyClient.SetTLSClientConfig(&tls.Config{
+		MinVersion: tls.VersionTLS12,
+		CipherSuites: []uint16{
+			tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+			tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+			tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
+			tls.TLS_RSA_WITH_AES_128_GCM_SHA256,
+		},
+	})
+
+	return &Client{
+		token:          token,
+		device:         device,
+		resty:          restyClient,
+		apiBaseURL:     dmURL,
+		fiscalEndpoint: "/dm/execute",
 	}
 }

api/fiscal.go

@@ -5,41 +5,45 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"log"
 )
 
 func (c *Client) executeRequest(ctx context.Context, request FiscalRequest, response interface{}) error {
-	//execute request with json body in request
+	request.Device = c.device
+
 	reqJson, err := json.Marshal(request)
 	if err != nil {
 		return fmt.Errorf("failed to marshal request: %w", err)
 	}
-	fmt.Println(string(reqJson))
+
+	url := c.apiBaseURL + c.fiscalEndpoint
+	log.Printf("[VCHASNO] POST %s", url)
+	log.Printf("[VCHASNO] Request: %s", string(reqJson))
 
 	resp, err := c.resty.R().
 		SetContext(ctx).
 		SetHeader("Authorization", c.token).
+		SetHeader("Content-Type", "application/json").
 		SetBody(reqJson).
-		Post(c.apiBaseURL + "/fiscal/execute")
+		Post(url)
 
 	if err != nil {
 		return fmt.Errorf("request failed: %w", err)
 	}
 
-	if resp.IsError() {
-		return fmt.Errorf("api error: %v", resp.Error())
-	}
-
-	if resp.StatusCode() != 200 {
-		return fmt.Errorf("unexpected status code: %d", resp.StatusCode())
-	}
-
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return fmt.Errorf("failed to read response: %w", err)
 	}
 
+	log.Printf("[VCHASNO] Response (status %d): %s", resp.StatusCode(), string(body))
+
+	if resp.StatusCode() != 200 {
+		return fmt.Errorf("api error (status %d): %s", resp.StatusCode(), string(body))
+	}
+
 	if err := json.Unmarshal(body, response); err != nil {
-		return fmt.Errorf("failed to unmarshal response: %w", err)
+		return fmt.Errorf("failed to unmarshal response: %w, body: %s", err, string(body))
 	}
 
 	return nil
@@ -102,12 +106,6 @@ func (c *Client) Sell(ctx context.Context, params SellParams) (*SellResponse, er
 		request.Userinfo = *params.Userinfo
 	}
 
-	reqJson, err := json.Marshal(request)
-	if err != nil {
-		return nil, err
-	}
-	fmt.Println(string(reqJson))
-
 	var response SellResponse
 	if err := c.executeRequest(ctx, request, &response); err != nil {
 		return nil, err

api/requests.go

@@ -2,6 +2,7 @@ package api
 
 type FiscalRequest struct {
 	Source   string   `json:"source"`
+	Device   string   `json:"device,omitempty"`
 	Userinfo Userinfo `json:"userinfo,omitempty"`
 	Fiscal   Fiscal   `json:"fiscal"`
 }

examples.go

@@ -10,6 +10,7 @@ func ExampleBasicUsage() {
 		Token:     "your-token",
 		Cashier:   "Иванов",
 		Source:    "parking",
+		CustomURL: "DM URL/",
 	})
 
 	ctx := context.Background()

vchasno.go

@@ -30,6 +30,8 @@ type Config struct {
 	Cashier   string
 	Source    string
 	Defaults  *DefaultParams
+	CustomURL string
+	Device    string
 }
 
 type DefaultParams struct {
@@ -65,8 +67,15 @@ func NewClient(config Config) *Client {
 		defaults.DefaultTimeout = 30 * time.Second
 	}
 
+	var apicfg *api.Client
+	if config.CustomURL == "" {
+		apicfg = api.NewClient(config.Token)
+	} else {
+		apicfg = api.NewDMClient(config.Token, config.CustomURL, config.Device)
+	}
+
 	return &Client{
-		api:      api.NewClient(config.Token),
+		api:      apicfg,
 		cashier:  config.Cashier,
 		source:   config.Source,
 		defaults: defaults,
@@ -274,3 +283,23 @@ func (c *Client) QuickSellNamed(ctx context.Context, name string, price float64)
 		Price: price,
 	})
 }
+
+func (c *Client) ZeroReceipt(ctx context.Context) (*api.SellResponse, error) {
+	return c.api.Sell(ctx, api.SellParams{
+		Cashier:   c.cashier,
+		Source:    c.source,
+		Rows:      []api.ReceiptRow{},
+		Pays:      []api.ReceiptPay{},
+		CommentUP: "Нульовий чек",
+	})
+}
+
+func (c *Client) ZeroReceiptWithTimeout(timeout time.Duration) (*api.SellResponse, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+	return c.ZeroReceipt(ctx)
+}
+
+func (c *Client) ZeroReceiptDefault() (*api.SellResponse, error) {
+	return c.ZeroReceiptWithTimeout(c.defaults.DefaultTimeout)
+}