diff --git a/README.md b/README.md
index 70b8764..cd24997 100644
--- a/README.md
+++ b/README.md
@@ -80,6 +80,13 @@ tier0 api /openapi/v1/uns/read --body '{"topics":["demo"]}'
 
 # 浏览命名空间
 tier0 api /openapi/v1/uns/browse --body '{"path":"/"}'
+
+# 上传 / 查询 UNS 附件
+tier0 uns attachments upload --uns-id 10001 --file manual.pdf
+tier0 uns attachments list --uns-id 10001
+
+# 绑定 UNS 节点到 SourceFlow
+tier0 uns bind-flow --uns-id 10001 --flow-id 20001
 ```
 
 ### 查看当前 API Key
@@ -126,6 +133,9 @@ tier0 flow create --name "alert-handler"    --event
 # 更新 Flow（名称、描述、收藏）
 tier0 flow update --id 1 --name "new-name" --favorite
 
+# 绑定 UNS 节点到 SourceFlow（flow-id 使用上面列表里的业务主键 ID）
+tier0 uns bind-flow --uns-id 10001 --flow-id 1
+
 # 删除 Flow（支持多个 ID）
 tier0 flow delete --id 1 --id 2
 tier0 flow delete 1,2,3
@@ -259,7 +269,7 @@ npx skills remove FREEZONEX/Tier0-skill
 
 | Version | Date | Notes |
 |---------|------|-------|
-| Unreleased | — | 新增 `tier0 auth whoami` 和 `tier0 flow nodes` |
+| Unreleased | — | 新增 `tier0 auth whoami`、`tier0 flow nodes`、`tier0 uns attachments`、`tier0 uns bind-flow`，`tier0 uns create` 支持 `--persistence` |
 | [v0.4.11](https://github.com/FREEZONEX/Tier0-cli/releases/tag/v0.4.11) | 2026-05-26 | 修复写操作忽略后端业务错误的问题 |
 | [v0.4.10](https://github.com/FREEZONEX/Tier0-cli/releases/tag/v0.4.10) | 2026-05-26 | 新增 `tier0 config --api-key` 直接设置 API Key |
 | [v0.4.9](https://github.com/FREEZONEX/Tier0-cli/releases/tag/v0.4.9) | 2026-05-26 | 新增 `tier0 uninstall`；修复安装版本错误（直接用 npm 包版本）；修复 release.sh JSON 400 |
diff --git a/cmd/uns.go b/cmd/uns.go
index 5cbeb41..6214c09 100644
--- a/cmd/uns.go
+++ b/cmd/uns.go
@@ -24,4 +24,6 @@ func init() {
 	unsCmd.AddCommand(unsSearchCmd)
 	unsCmd.AddCommand(unsHistoryCmd)
 	unsCmd.AddCommand(unsRestoreCmd)
+	unsCmd.AddCommand(unsAttachmentsCmd)
+	unsCmd.AddCommand(unsBindFlowCmd)
 }
diff --git a/cmd/uns_attachments.go b/cmd/uns_attachments.go
new file mode 100644
index 0000000..6046624
--- /dev/null
+++ b/cmd/uns_attachments.go
@@ -0,0 +1,176 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/FREEZONEX/Tier0-cli/internal/cmdutil"
+	"github.com/FREEZONEX/Tier0-cli/internal/i18n"
+	"github.com/FREEZONEX/Tier0-cli/internal/notice"
+	"github.com/spf13/cobra"
+)
+
+var unsAttachmentsCmd = &cobra.Command{
+	Use:     "attachments",
+	Aliases: []string{"attachment", "files"},
+	Short:   i18n.T("Manage UNS attachments", "管理 UNS 附件"),
+	Long: i18n.T(
+		"Upload and list files bound to a UNS node by unsId.",
+		"按 unsId 上传和查询绑定到 UNS 节点的附件。",
+	),
+}
+
+var unsAttachmentUploadCmd = &cobra.Command{
+	Use:   "upload",
+	Short: i18n.T("Upload a file attachment to a UNS node", "上传 UNS 节点附件"),
+	RunE:  runUnsAttachmentUpload,
+}
+
+var unsAttachmentListCmd = &cobra.Command{
+	Use:     "list",
+	Aliases: []string{"ls"},
+	Short:   i18n.T("List attachments of a UNS node", "查询 UNS 节点附件"),
+	RunE:    runUnsAttachmentList,
+}
+
+func init() {
+	unsAttachmentsCmd.AddCommand(unsAttachmentUploadCmd)
+	unsAttachmentsCmd.AddCommand(unsAttachmentListCmd)
+
+	unsAttachmentUploadCmd.Flags().Int64("uns-id", 0,
+		i18n.T("UNS node ID (required)", "UNS 节点 ID（必填）"))
+	unsAttachmentUploadCmd.Flags().StringP("file", "f", "",
+		i18n.T("Local file path to upload (required)", "要上传的本地文件路径（必填）"))
+	unsAttachmentUploadCmd.Flags().String("file-name", "",
+		i18n.T("Override attachment fileName", "覆盖附件 fileName"))
+	unsAttachmentUploadCmd.Flags().String("sha256", "",
+		i18n.T("Optional client-side sha256", "可选的客户端 sha256"))
+	unsAttachmentUploadCmd.MarkFlagRequired("uns-id")
+	unsAttachmentUploadCmd.MarkFlagRequired("file")
+
+	unsAttachmentListCmd.Flags().Int64("uns-id", 0,
+		i18n.T("UNS node ID (required)", "UNS 节点 ID（必填）"))
+	unsAttachmentListCmd.Flags().Int("page-no", 1,
+		i18n.T("Page number", "页码"))
+	unsAttachmentListCmd.Flags().Int("page-size", 20,
+		i18n.T("Page size", "每页条数"))
+	unsAttachmentListCmd.Flags().Bool("include-file-url", true,
+		i18n.T("Include downloadable fileUrl", "返回可下载 fileUrl"))
+	unsAttachmentListCmd.MarkFlagRequired("uns-id")
+}
+
+func runUnsAttachmentUpload(cmd *cobra.Command, args []string) error {
+	checker := notice.Start()
+	jsonMode, _ := cmd.Flags().GetBool("json")
+	debug, _ := cmd.Flags().GetBool("debug")
+	unsID, _ := cmd.Flags().GetInt64("uns-id")
+	filePath, _ := cmd.Flags().GetString("file")
+	fileName, _ := cmd.Flags().GetString("file-name")
+	sha256, _ := cmd.Flags().GetString("sha256")
+
+	if unsID <= 0 {
+		return fmt.Errorf(i18n.T("uns-id is required", "uns-id 为必填"))
+	}
+	if strings.TrimSpace(filePath) == "" {
+		return fmt.Errorf(i18n.T("file is required", "file 为必填"))
+	}
+
+	endpoint := fmt.Sprintf("/openapi/v1/uns/%d/attachments", unsID)
+	fields := map[string]string{
+		"fileName": fileName,
+		"sha256":   sha256,
+	}
+	resp, err := cmdutil.DoMultipart(cmd.Context(), endpoint, "file", filePath, fileName, fields, debug)
+	if err != nil {
+		return cmdutil.HandleCommandError(cmd.ErrOrStderr(), err, jsonMode)
+	}
+	if err := cmdutil.CheckOK(resp); err != nil {
+		return cmdutil.HandleCommandError(cmd.ErrOrStderr(), err, jsonMode)
+	}
+
+	stdout := cmd.OutOrStdout()
+	if jsonMode {
+		checker.Emit(resp, true, stdout, cmd.ErrOrStderr())
+		return nil
+	}
+	var result struct {
+		UnsID    int64  `json:"unsId"`
+		FileName string `json:"fileName"`
+		FilePath string `json:"filePath"`
+		FileURL  string `json:"fileUrl"`
+	}
+	if err := json.Unmarshal([]byte(cmdutil.ExtractData(resp)), &result); err != nil {
+		fmt.Fprintln(stdout, resp)
+		checker.Emit("", false, stdout, cmd.ErrOrStderr())
+		return nil
+	}
+	fmt.Fprintf(stdout, i18n.T("✓ Attachment uploaded: %s\n", "✓ 附件上传成功: %s\n"), result.FileName)
+	fmt.Fprintf(stdout, "unsId: %d\nfilePath: %s\n", result.UnsID, result.FilePath)
+	if result.FileURL != "" {
+		fmt.Fprintf(stdout, "fileUrl: %s\n", result.FileURL)
+	}
+	checker.Emit("", false, stdout, cmd.ErrOrStderr())
+	return nil
+}
+
+func runUnsAttachmentList(cmd *cobra.Command, args []string) error {
+	checker := notice.Start()
+	jsonMode, _ := cmd.Flags().GetBool("json")
+	debug, _ := cmd.Flags().GetBool("debug")
+	unsID, _ := cmd.Flags().GetInt64("uns-id")
+	pageNo, _ := cmd.Flags().GetInt("page-no")
+	pageSize, _ := cmd.Flags().GetInt("page-size")
+	includeFileURL, _ := cmd.Flags().GetBool("include-file-url")
+
+	if unsID <= 0 {
+		return fmt.Errorf(i18n.T("uns-id is required", "uns-id 为必填"))
+	}
+	q := url.Values{}
+	q.Set("pageNo", strconv.Itoa(pageNo))
+	q.Set("pageSize", strconv.Itoa(pageSize))
+	q.Set("includeFileUrl", strconv.FormatBool(includeFileURL))
+	endpoint := fmt.Sprintf("/openapi/v1/uns/%d/attachments/list?%s", unsID, q.Encode())
+
+	resp, err := cmdutil.DoAPI(cmd.Context(), endpoint, "POST", "", debug)
+	if err != nil {
+		return cmdutil.HandleCommandError(cmd.ErrOrStderr(), err, jsonMode)
+	}
+	if err := cmdutil.CheckOK(resp); err != nil {
+		return cmdutil.HandleCommandError(cmd.ErrOrStderr(), err, jsonMode)
+	}
+
+	stdout := cmd.OutOrStdout()
+	if jsonMode {
+		checker.Emit(resp, true, stdout, cmd.ErrOrStderr())
+		return nil
+	}
+	var result struct {
+		List []struct {
+			FileName string `json:"fileName"`
+			FilePath string `json:"filePath"`
+			FileURL  string `json:"fileUrl"`
+		} `json:"list"`
+		Total int64 `json:"total"`
+	}
+	if err := json.Unmarshal([]byte(cmdutil.ExtractData(resp)), &result); err != nil {
+		fmt.Fprintln(stdout, resp)
+		checker.Emit("", false, stdout, cmd.ErrOrStderr())
+		return nil
+	}
+	if len(result.List) == 0 {
+		checker.Emit("", false, stdout, cmd.ErrOrStderr())
+		fmt.Fprintln(stdout, i18n.T("No attachments found.", "暂无附件。"))
+		return nil
+	}
+	fmt.Fprintf(stdout, "%-30s  %-48s  %s\n", i18n.T("FileName", "文件名"), "FilePath", "FileUrl")
+	fmt.Fprintln(stdout, strings.Repeat("-", 120))
+	for _, item := range result.List {
+		fmt.Fprintf(stdout, "%-30s  %-48s  %s\n", item.FileName, item.FilePath, item.FileURL)
+	}
+	fmt.Fprintf(stdout, i18n.T("Total: %d\n", "总数: %d\n"), result.Total)
+	checker.Emit("", false, stdout, cmd.ErrOrStderr())
+	return nil
+}
diff --git a/cmd/uns_bind_flow.go b/cmd/uns_bind_flow.go
new file mode 100644
index 0000000..d4bdf3f
--- /dev/null
+++ b/cmd/uns_bind_flow.go
@@ -0,0 +1,73 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+
+	"github.com/FREEZONEX/Tier0-cli/internal/cmdutil"
+	"github.com/FREEZONEX/Tier0-cli/internal/i18n"
+	"github.com/FREEZONEX/Tier0-cli/internal/notice"
+	"github.com/spf13/cobra"
+)
+
+var unsBindFlowCmd = &cobra.Command{
+	Use:   "bind-flow",
+	Short: i18n.T("Bind a UNS node to a SourceFlow", "绑定 UNS 节点到 SourceFlow"),
+	Long: i18n.T(
+		"Bind a UNS node to a SourceFlow using unsId and flow business ID.",
+		"使用 unsId 和 Flow 业务主键 ID 关联 UNS 节点与 SourceFlow。",
+	),
+	RunE: runUnsBindFlow,
+}
+
+func init() {
+	unsBindFlowCmd.Flags().Int64("uns-id", 0,
+		i18n.T("UNS node ID (required)", "UNS 节点 ID（必填）"))
+	unsBindFlowCmd.Flags().Int64("flow-id", 0,
+		i18n.T("Flow business ID (required)", "Flow 业务主键 ID（必填）"))
+	unsBindFlowCmd.MarkFlagRequired("uns-id")
+	unsBindFlowCmd.MarkFlagRequired("flow-id")
+}
+
+func runUnsBindFlow(cmd *cobra.Command, args []string) error {
+	checker := notice.Start()
+	jsonMode, _ := cmd.Flags().GetBool("json")
+	debug, _ := cmd.Flags().GetBool("debug")
+	unsID, _ := cmd.Flags().GetInt64("uns-id")
+	flowID, _ := cmd.Flags().GetInt64("flow-id")
+
+	if unsID == 0 && len(args) > 0 {
+		unsID, _ = strconv.ParseInt(args[0], 10, 64)
+	}
+	if flowID == 0 && len(args) > 1 {
+		flowID, _ = strconv.ParseInt(args[1], 10, 64)
+	}
+	if unsID <= 0 || flowID <= 0 {
+		return fmt.Errorf(i18n.T(
+			"specify --uns-id <id> and --flow-id <id>",
+			"请指定 --uns-id <id> 和 --flow-id <id>",
+		))
+	}
+
+	body, _ := json.Marshal(map[string]int64{
+		"unsId":  unsID,
+		"flowId": flowID,
+	})
+	resp, err := cmdutil.DoAPI(cmd.Context(), "/openapi/v1/uns/unsBindFlow", "POST", string(body), debug)
+	if err != nil {
+		return cmdutil.HandleCommandError(cmd.ErrOrStderr(), err, jsonMode)
+	}
+	if err := cmdutil.CheckOK(resp); err != nil {
+		return cmdutil.HandleCommandError(cmd.ErrOrStderr(), err, jsonMode)
+	}
+
+	stdout := cmd.OutOrStdout()
+	if jsonMode {
+		checker.Emit(resp, true, stdout, cmd.ErrOrStderr())
+		return nil
+	}
+	fmt.Fprintf(stdout, i18n.T("✓ UNS %d bound to Flow %d\n", "✓ UNS %d 已绑定到 Flow %d\n"), unsID, flowID)
+	checker.Emit("", false, stdout, cmd.ErrOrStderr())
+	return nil
+}
diff --git a/cmd/uns_create.go b/cmd/uns_create.go
index 68a876c..626256d 100644
--- a/cmd/uns_create.go
+++ b/cmd/uns_create.go
@@ -38,6 +38,8 @@ func init() {
 		i18n.T("Topic type", "Topic 类型"))
 	unsCreateCmd.Flags().String("fields", "",
 		i18n.T("Schema fields JSON array (e.g. '[{\"name\":\"temp\",\"type\":\"float\"}]')", "Schema 字段 JSON 数组"))
+	unsCreateCmd.Flags().Bool("persistence", false,
+		i18n.T("Persist topic values to history storage", "持久化保存点位历史数据"))
 }
 
 func runUnsCreate(cmd *cobra.Command, args []string) error {
@@ -52,6 +54,7 @@ func runUnsCreate(cmd *cobra.Command, args []string) error {
 	file, _ := cmd.Flags().GetString("file")
 	topicType, _ := cmd.Flags().GetString("topic-type")
 	fields, _ := cmd.Flags().GetString("fields")
+	persistence, _ := cmd.Flags().GetBool("persistence")
 
 	var namespace []any
 
@@ -93,6 +96,9 @@ func runUnsCreate(cmd *cobra.Command, args []string) error {
 			}
 			node["fields"] = fieldList
 		}
+		if persistence {
+			node["persistence"] = true
+		}
 		namespace = []any{node}
 	}
 
diff --git a/internal/auth/setup.go b/internal/auth/setup.go
index f6b4071..c0bf10c 100644
--- a/internal/auth/setup.go
+++ b/internal/auth/setup.go
@@ -90,7 +90,7 @@ func PollSetupCheck(ctx context.Context, baseURL, setupCode string, onPoll func(
 				APIKey        string `json:"apiKey"`
 				WorkspaceID   string `json:"workspaceID"`
 				WorkspaceName string `json:"workspaceName"`
-				ExpiresAt     string `json:"expiresAt"`
+				ExpiresAt     any    `json:"expiresAt"`
 			} `json:"data"`
 		}
 		if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
@@ -103,7 +103,7 @@ func PollSetupCheck(ctx context.Context, baseURL, setupCode string, onPoll func(
 		}
 		resp.Body.Close()
 
-		if result.Code != 200 {
+		if result.Code != 0 && result.Code != 200 {
 			err := fmt.Errorf("setup-check failed: %s", result.Msg)
 			if onPoll != nil {
 				onPoll(i, maxPollCount, false, err)
diff --git a/internal/client/client.go b/internal/client/client.go
index 2c97e5b..0c8ec4b 100644
--- a/internal/client/client.go
+++ b/internal/client/client.go
@@ -6,8 +6,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"mime/multipart"
 	"net/http"
 	"os"
+	"path/filepath"
 	"regexp"
 	"strings"
 	"time"
@@ -100,6 +102,95 @@ func (c *Client) DoAPI(ctx context.Context, endpoint, method, body string, debug
 	return string(respBody), nil
 }
 
+// DoMultipart uploads one file plus optional form fields to an API endpoint.
+func (c *Client) DoMultipart(ctx context.Context, endpoint, fileField, filePath, fileName string, fields map[string]string, debug bool) (string, error) {
+	if fileField == "" {
+		fileField = "file"
+	}
+	file, err := os.Open(filePath)
+	if err != nil {
+		return "", fmt.Errorf("打开文件失败: %w", err)
+	}
+	defer file.Close()
+
+	if strings.TrimSpace(fileName) == "" {
+		fileName = filepath.Base(filePath)
+	}
+
+	var buf bytes.Buffer
+	writer := multipart.NewWriter(&buf)
+	for key, value := range fields {
+		if value == "" {
+			continue
+		}
+		if err := writer.WriteField(key, value); err != nil {
+			return "", fmt.Errorf("写入表单字段失败: %w", err)
+		}
+	}
+	part, err := writer.CreateFormFile(fileField, fileName)
+	if err != nil {
+		return "", fmt.Errorf("创建文件表单失败: %w", err)
+	}
+	if _, err := io.Copy(part, file); err != nil {
+		return "", fmt.Errorf("读取文件失败: %w", err)
+	}
+	if err := writer.Close(); err != nil {
+		return "", fmt.Errorf("关闭 multipart writer 失败: %w", err)
+	}
+
+	url := c.baseURL + endpoint
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, &buf)
+	if err != nil {
+		return "", fmt.Errorf("构建请求失败: %w", err)
+	}
+	req.Header.Set("Content-Type", writer.FormDataContentType())
+	if c.apiKey != "" {
+		req.Header.Set("x-api-key", c.apiKey)
+	}
+
+	if debug {
+		fmt.Fprintf(os.Stderr, "[debug] ---------- HTTP Request ----------\n")
+		fmt.Fprintf(os.Stderr, "[debug] %s %s\n", req.Method, req.URL.String())
+		for key, values := range req.Header {
+			for _, v := range values {
+				if strings.EqualFold(key, "x-api-key") {
+					v = v[:min(len(v), 8)] + "..."
+				}
+				fmt.Fprintf(os.Stderr, "[debug] %s: %s\n", key, v)
+			}
+		}
+		fmt.Fprintf(os.Stderr, "[debug] Multipart file: field=%s path=%s name=%s\n", fileField, filePath, fileName)
+		fmt.Fprintf(os.Stderr, "[debug] ----------------------------------\n")
+	}
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("发送请求失败: %w", err)
+	}
+	defer resp.Body.Close()
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", fmt.Errorf("读取响应失败: %w", err)
+	}
+
+	if debug {
+		fmt.Fprintf(os.Stderr, "[debug] ---------- HTTP Response ---------\n")
+		fmt.Fprintf(os.Stderr, "[debug] Status: %d %s\n", resp.StatusCode, resp.Status)
+		if len(respBody) > 4096 {
+			fmt.Fprintf(os.Stderr, "[debug] Body: %s... (%d bytes truncated)\n", string(respBody[:4096]), len(respBody))
+		} else {
+			fmt.Fprintf(os.Stderr, "[debug] Body: %s\n", string(respBody))
+		}
+		fmt.Fprintf(os.Stderr, "[debug] ----------------------------------\n")
+	}
+
+	if resp.StatusCode >= 400 {
+		return "", apierr.New(resp.StatusCode, string(respBody))
+	}
+	return string(respBody), nil
+}
+
 // fixJSON 尝试修复 PowerShell 等环境导致的 JSON 引号丢失
 // 例如 {path:/} → {"path":"/"}
 func fixJSON(body string) string {
diff --git a/internal/cmdutil/helpers.go b/internal/cmdutil/helpers.go
index 4321046..9bf09ee 100644
--- a/internal/cmdutil/helpers.go
+++ b/internal/cmdutil/helpers.go
@@ -29,6 +29,19 @@ func DoAPI(ctx context.Context, endpoint, method, body string, debug bool) (stri
 	return c.DoAPI(ctx, endpoint, method, body, debug)
 }
 
+// DoMultipart loads the profile, creates a client, and uploads a multipart file.
+func DoMultipart(ctx context.Context, endpoint, fileField, filePath, fileName string, fields map[string]string, debug bool) (string, error) {
+	profile, err := config.LoadProfile()
+	if err != nil {
+		return "", fmt.Errorf(i18n.T("failed to load config: %w", "加载配置失败: %w"), err)
+	}
+	if profile.APIKey == "" {
+		return "", apierr.New(401, `{"code":401,"msg":"API Key not found"}`)
+	}
+	c := client.New(profile.BaseURL, profile.APIKey)
+	return c.DoMultipart(ctx, endpoint, fileField, filePath, fileName, fields, debug)
+}
+
 // ResolveBaseURL resolves the effective base URL from arg, env, or config.
 func ResolveBaseURL(baseURLArg string) string {
 	if baseURLArg != "" {
@@ -90,6 +103,7 @@ func JSONString(v any) string {
 //   - code 200  → success
 //   - code 0    → field absent / zero-valued, treat as success
 //   - anything else (400, 500, …) → failure
+//   - data.success false → bulk operation has failed items
 //
 // HTTP-level errors (4xx/5xx status) are already handled by DoAPI; this catches
 // the cases where the server responds HTTP 200 but embeds an error in the body.
@@ -97,6 +111,10 @@ func CheckOK(resp string) error {
 	var rv struct {
 		Code int    `json:"code"`
 		Msg  string `json:"msg"`
+		Data struct {
+			Success *bool            `json:"success"`
+			Results []bulkResultItem `json:"results"`
+		} `json:"data"`
 	}
 	if err := json.Unmarshal([]byte(resp), &rv); err != nil {
 		return nil // not a standard envelope, assume OK
@@ -104,9 +122,45 @@ func CheckOK(resp string) error {
 	if rv.Code != 0 && rv.Code != 200 {
 		return apierr.New(rv.Code, resp)
 	}
+	if rv.Data.Success != nil && !*rv.Data.Success {
+		code, msg := firstBulkError(rv.Data.Results)
+		if msg == "" {
+			msg = "batch operation failed"
+		}
+		if code == 0 {
+			code = 400
+		}
+		return apierr.New(code, JSONString(map[string]any{"code": code, "msg": msg}))
+	}
 	return nil
 }
 
+type bulkResultItem struct {
+	Success *bool  `json:"success"`
+	Topic   string `json:"topic"`
+	Error   *struct {
+		Code    int    `json:"code"`
+		Message string `json:"message"`
+	} `json:"error,omitempty"`
+}
+
+func firstBulkError(results []bulkResultItem) (int, string) {
+	for _, item := range results {
+		if item.Success != nil && *item.Success {
+			continue
+		}
+		if item.Error == nil {
+			continue
+		}
+		msg := item.Error.Message
+		if item.Topic != "" && msg != "" {
+			msg = item.Topic + ": " + msg
+		}
+		return item.Error.Code, msg
+	}
+	return 0, ""
+}
+
 // ExtractData unwraps the standard backend envelope {"code":N,"msg":"...","data":{...}}
 // and returns the raw JSON of the "data" field.
 // If the response has no "data" field the original string is returned unchanged,