diff --git a/internal/handler/agent.go b/internal/handler/agent.go
index 4ef972d8b6..e947f2e6bd 100644
--- a/internal/handler/agent.go
+++ b/internal/handler/agent.go
@@ -435,11 +435,7 @@ func (h *AgentHandler) ListAgentVersions(c *gin.Context) {
 
 	versions, err := h.agentService.ListVersions(agentID)
 	if err != nil {
-		c.JSON(http.StatusOK, gin.H{
-			"code":    common.CodeServerError,
-			"data":    nil,
-			"message": err.Error(),
-		})
+		jsonInternalError(c, err)
 		return
 	}
 
@@ -466,7 +462,7 @@ func (h *AgentHandler) ListTemplates(c *gin.Context) {
 
 	templates, err := h.agentService.ListTemplates()
 	if err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}
 	if templates == nil {
diff --git a/internal/handler/datasets.go b/internal/handler/datasets.go
index 426b7c1318..346aded370 100644
--- a/internal/handler/datasets.go
+++ b/internal/handler/datasets.go
@@ -373,7 +373,7 @@ func (h *DatasetsHandler) GetKnowledgeGraph(c *gin.Context) {
 	indexName := fmt.Sprintf("ragflow_%s", tenantID)
 	exists, err := docEngine.ChunkStoreExists(c.Request.Context(), indexName, datasetID)
 	if err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}
 
@@ -398,7 +398,7 @@ func (h *DatasetsHandler) GetKnowledgeGraph(c *gin.Context) {
 		},
 	})
 	if err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}
 	if searchResult == nil || len(searchResult.Chunks) == 0 {
@@ -473,7 +473,7 @@ func (h *DatasetsHandler) DeleteKnowledgeGraph(c *gin.Context) {
 	if _, err := docEngine.DeleteChunks(c.Request.Context(), map[string]interface{}{
 		"knowledge_graph_kwd": []string{"graph", "subgraph", "entity", "relation", "community_report"},
 	}, indexName, datasetID); err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}
 
diff --git a/internal/handler/error.go b/internal/handler/error.go
index 97d390ef78..2194b793e5 100644
--- a/internal/handler/error.go
+++ b/internal/handler/error.go
@@ -18,12 +18,24 @@ package handler
 
 import (
 	"net/http"
+
 	"ragflow/internal/common"
 
 	"github.com/gin-gonic/gin"
 	"go.uber.org/zap"
 )
 
+// jsonInternalError logs the original error while returning a generic message
+// to avoid exposing internal implementation details in API responses.
+func jsonInternalError(c *gin.Context, err error) {
+	common.Warn("handler internal error",
+		zap.Error(err),
+		zap.String("method", c.Request.Method),
+		zap.String("path", c.Request.URL.Path),
+	)
+	jsonError(c, common.CodeServerError, common.CodeServerError.Message())
+}
+
 // HandleNoRoute handles requests to undefined routes
 func HandleNoRoute(c *gin.Context) {
 	// Python parity: GET /api/v1/auth/login/ (an empty OAuth channel) resolves
diff --git a/internal/handler/error_response_test.go b/internal/handler/error_response_test.go
new file mode 100644
index 0000000000..b0d4287da1
--- /dev/null
+++ b/internal/handler/error_response_test.go
@@ -0,0 +1,59 @@
+//
+//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//
+
+package handler
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"ragflow/internal/common"
+
+	"github.com/gin-gonic/gin"
+)
+
+func TestJSONInternalErrorRedactsRawError(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	recorder := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(recorder)
+	c.Request = httptest.NewRequest(http.MethodGet, "/api/v1/files?tenant_id=secret-tenant", nil)
+
+	jsonInternalError(c, errors.New("postgres password=secret host=10.0.0.1 table=tenant"))
+
+	if recorder.Code != http.StatusOK {
+		t.Fatalf("status=%d, want %d", recorder.Code, http.StatusOK)
+	}
+
+	var body map[string]interface{}
+	if err := json.Unmarshal(recorder.Body.Bytes(), &body); err != nil {
+		t.Fatalf("decode response body: %v", err)
+	}
+
+	if got := body["message"]; got != common.CodeServerError.Message() {
+		t.Fatalf("message=%v, want %q", got, common.CodeServerError.Message())
+	}
+	if got := body["code"]; got != float64(common.CodeServerError) {
+		t.Fatalf("code=%v, want %d", got, common.CodeServerError)
+	}
+	if strings.Contains(recorder.Body.String(), "password=secret") || strings.Contains(recorder.Body.String(), "10.0.0.1") {
+		t.Fatalf("response leaked raw error details: %s", recorder.Body.String())
+	}
+}
diff --git a/internal/handler/file.go b/internal/handler/file.go
index b040254547..140569e961 100644
--- a/internal/handler/file.go
+++ b/internal/handler/file.go
@@ -108,7 +108,7 @@ func (h *FileHandler) ListFiles(c *gin.Context) {
 
 	result, err := h.fileService.ListFiles(userID, parentID, page, pageSize, orderby, desc, keywords)
 	if err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}
 
@@ -138,7 +138,7 @@ func (h *FileHandler) GetRootFolder(c *gin.Context) {
 	// Get root folder
 	rootFolder, err := h.fileService.GetRootFolder(userID)
 	if err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}
 
@@ -176,7 +176,7 @@ func (h *FileHandler) GetParentFolder(c *gin.Context) {
 	// Get parent folder with permission check
 	parentFolder, err := h.fileService.GetParentFolder(userID, fileID)
 	if err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}
 
@@ -214,7 +214,7 @@ func (h *FileHandler) GetAllParentFolders(c *gin.Context) {
 	// Get all parent folders with permission check
 	parentFolders, err := h.fileService.GetAllParentFolders(userID, fileID)
 	if err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}
 
@@ -251,7 +251,7 @@ func (h *FileHandler) GetFileAncestors(c *gin.Context) {
 	// Get all parent folders with permission check
 	parentFolders, err := h.fileService.GetAllParentFolders(userID, fileID)
 	if err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}
 
@@ -305,7 +305,7 @@ func (h *FileHandler) UploadFile(c *gin.Context) {
 		if parentID == "" {
 			rootFolder, err := h.fileService.GetRootFolder(userID)
 			if err != nil {
-				jsonError(c, common.CodeServerError, err.Error())
+				jsonInternalError(c, err)
 				return
 			}
 			parentID = rootFolder["id"].(string)
@@ -352,7 +352,7 @@ func (h *FileHandler) UploadFile(c *gin.Context) {
 		if parentID == "" {
 			rootFolder, err := h.fileService.GetRootFolder(userID)
 			if err != nil {
-				jsonError(c, common.CodeServerError, err.Error())
+				jsonInternalError(c, err)
 				return
 			}
 			parentID = rootFolder["id"].(string)
diff --git a/internal/handler/kb.go b/internal/handler/kb.go
index 5ba5e0543a..e2997ec34b 100644
--- a/internal/handler/kb.go
+++ b/internal/handler/kb.go
@@ -187,7 +187,7 @@ func (h *KnowledgebaseHandler) GetDetail(c *gin.Context) {
 		return
 	}
 
-		jsonResponse(c, common.CodeSuccess, result, "success")
+	jsonResponse(c, common.CodeSuccess, result, "success")
 }
 
 // ListTags handles the list tags request for a knowledge base
@@ -432,4 +432,4 @@ func (h *KnowledgebaseHandler) GetBasicInfo(c *gin.Context) {
 	}
 
 	jsonResponse(c, common.CodeSuccess, map[string]interface{}{}, "success")
-}
\ No newline at end of file
+}
diff --git a/internal/handler/system.go b/internal/handler/system.go
index e5ac475a17..ba49d3814c 100644
--- a/internal/handler/system.go
+++ b/internal/handler/system.go
@@ -125,7 +125,7 @@ func (h *SystemHandler) GetStatus(c *gin.Context) {
 
 	status, err := h.systemService.GetStatus()
 	if err != nil {
-		jsonError(c, common.CodeServerError, err.Error())
+		jsonInternalError(c, err)
 		return
 	}