fix: identify Ark runtime SDK version in user agent

arkruntime/client.go

@@ -25,6 +25,7 @@ import (
 	"github.com/volcengine/volcengine-go-sdk/volcengine/session"
 	"github.com/volcengine/volcengine-go-sdk/volcengine/volcengineerr"
 
+	sdk "github.com/volcengine/ark-runtime-go"
 	"github.com/volcengine/ark-runtime-go/arkruntime/model"
 	"github.com/volcengine/ark-runtime-go/arkruntime/utils"
 )
@@ -285,6 +286,7 @@ func (c *Client) newRequest(ctx context.Context, method, url, _, resourceId stri
 		header: make(http.Header),
 	}
 	args.query = make(map[string][]string)
+	args.header.Set("User-Agent", "ark-runtime-go/"+sdk.Version())
 
 	requestID := utils.GenRequestId()
 	args.header.Set(model.ClientRequestHeader, requestID)

arkruntime/user_agent_test.go

@@ -0,0 +1,65 @@
+// Copyright (c) 2026 ByteDance Ltd. and/or its affiliates.
+// SPDX-License-Identifier: Apache-2.0
+
+package arkruntime_test
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/volcengine/ark-runtime-go/arkruntime"
+	"github.com/volcengine/ark-runtime-go/arkruntime/model/images"
+)
+
+func TestRequestUserAgent(t *testing.T) {
+	version, err := os.ReadFile("../VERSION")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, test := range []struct {
+		name     string
+		custom   bool
+		value    string
+		expected string
+	}{
+		{name: "repository version", expected: "ark-runtime-go/" + strings.TrimSpace(string(version))},
+		{name: "custom override", custom: true, value: "my-app/2.0", expected: "my-app/2.0"},
+		{name: "explicitly disabled", custom: true},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			headers := make(chan http.Header, 1)
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				headers <- r.Header.Clone()
+				w.Header().Set("Content-Type", "application/json")
+				_, _ = w.Write([]byte(`{"model":"test-model","created":1,"data":[]}`))
+			}))
+			defer server.Close()
+			client := arkruntime.NewClientWithApiKey("test-key",
+				arkruntime.WithBaseUrl(server.URL), arkruntime.WithRetryTimes(0))
+			request := &images.CreateImageGenerationRequest{Model: "test-model", Prompt: "test"}
+			if test.custom {
+				_, err = client.GenerateImages(context.Background(), request,
+					arkruntime.WithCustomHeader("User-Agent", test.value))
+			} else {
+				_, err = client.GenerateImages(context.Background(), request)
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			got := <-headers
+			if got.Get("User-Agent") != test.expected {
+				t.Errorf("User-Agent = %q, want %q", got.Get("User-Agent"), test.expected)
+			}
+			if got.Get("X-Client-Request-Id") == "" {
+				t.Error("missing client request ID")
+			}
+			if got.Get("Authorization") != "Bearer test-key" {
+				t.Error("authentication header changed")
+			}
+		})
+	}
+}

version.go

@@ -0,0 +1,18 @@
+// Copyright (c) 2026 ByteDance Ltd. and/or its affiliates.
+// SPDX-License-Identifier: Apache-2.0
+
+// Package arkruntime provides build metadata for the Ark runtime SDK.
+package arkruntime
+
+import (
+	_ "embed"
+	"strings"
+)
+
+//go:embed VERSION
+var version string
+
+// Version returns the SDK version embedded from the repository's VERSION file.
+func Version() string {
+	return strings.TrimSpace(version)
+}