feat: add Go MCP server list API (#15253)

## What
#15240 
Implements `GET /api/v1/mcp/servers` in the Go API server.

## Changes

- Added MCP server DAO list query with tenant scoping.
- Added MCP service response wrapper.
- Added MCP handler for list request parsing and response formatting.
- Wired `GET /api/v1/mcp/servers` under authenticated `/api/v1` routes.
- Initialized MCP service and handler in the Go server startup.
- update_time and update_date now both map to update_date
- create_time and create_date now both map to create_date
- default ordering now returns create_date
## API Behavior

Matches the Python endpoint behavior:

- Requires authenticated user.
- Lists MCP servers for the current user tenant.
- Supports `keywords`.
- Supports `mcp_id` and repeated/comma-separated `mcp_ids`.
- Supports `page`, `page_size`, `orderby`, and `desc`.
- Returns:

```json
{
  "code": 0,
  "message": "success",
  "data": {
    "mcp_servers": [],
    "total": 0
  }
}
```

internal/service/mcp.go

@@ -21,6 +21,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"time"
 
 	"ragflow/internal/common"
 	"ragflow/internal/dao"
@@ -31,6 +32,7 @@ const (
 	mcpServerTypeSSE            = "sse"
 	mcpServerTypeStreamableHTTP = "streamable-http"
 	mcpServerNameLimit          = 255
+	mcpServerDateFormat         = "2006-01-02T15:04:05"
 )
 
 // MCPService handles MCP server operations.
@@ -69,6 +71,24 @@ type CreateMCPServerResponse struct {
 	Headers     entity.JSONMap `json:"headers"`
 }
 
+// MCPServerListItem is an MCP server item in the list response.
+type MCPServerListItem struct {
+	ID          string         `json:"id"`
+	Name        string         `json:"name"`
+	ServerType  string         `json:"server_type"`
+	URL         string         `json:"url"`
+	Description *string        `json:"description"`
+	Variables   entity.JSONMap `json:"variables"`
+	CreateDate  *string        `json:"create_date"`
+	UpdateDate  *string        `json:"update_date"`
+}
+
+// ListMCPServersResponse is the response payload for listing MCP servers.
+type ListMCPServersResponse struct {
+	MCPServers []*MCPServerListItem `json:"mcp_servers"`
+	Total      int64                `json:"total"`
+}
+
 // CreateMCPServer creates an MCP server owned by a tenant.
 func (s *MCPService) CreateMCPServer(tenantID string, req CreateMCPServerRequest) (*CreateMCPServerResponse, common.ErrorCode, error) {
 	if !isValidMCPServerType(req.ServerType) {
@@ -127,6 +147,45 @@ func (s *MCPService) CreateMCPServer(tenantID string, req CreateMCPServerRequest
 	}, common.CodeSuccess, nil
 }
 
+// ListMCPServers lists MCP servers owned by a tenant.
+func (s *MCPService) ListMCPServers(tenantID string, ids []string, keywords string, page, pageSize int, orderby string, desc bool) (*ListMCPServersResponse, common.ErrorCode, error) {
+	servers, total, err := s.mcpServerDAO.ListMCPServers(tenantID, ids, keywords, orderby, desc)
+	if err != nil {
+		var orderbyErr *dao.InvalidMCPServerOrderByError
+		if errors.As(err, &orderbyErr) {
+			return nil, common.CodeExceptionError, err
+		}
+		return nil, common.CodeServerError, err
+	}
+	if servers == nil {
+		servers = []*entity.MCPServer{}
+	}
+	servers = paginateMCPServers(servers, page, pageSize)
+
+	items := make([]*MCPServerListItem, 0, len(servers))
+	for _, server := range servers {
+		variables := server.Variables
+		if variables == nil {
+			variables = entity.JSONMap{}
+		}
+		items = append(items, &MCPServerListItem{
+			ID:          server.ID,
+			Name:        server.Name,
+			ServerType:  server.ServerType,
+			URL:         server.URL,
+			Description: server.Description,
+			Variables:   variables,
+			CreateDate:  formatMCPServerDate(server.CreateDate),
+			UpdateDate:  formatMCPServerDate(server.UpdateDate),
+		})
+	}
+
+	return &ListMCPServersResponse{
+		MCPServers: items,
+		Total:      total,
+	}, common.CodeSuccess, nil
+}
+
 // DeleteMCPServer deletes an MCP server owned by a tenant.
 func (s *MCPService) DeleteMCPServer(tenantID, mcpID string) (bool, common.ErrorCode, error) {
 	server, err := s.mcpServerDAO.GetByID(mcpID)
@@ -177,3 +236,44 @@ func safeJSONMap(raw json.RawMessage) entity.JSONMap {
 	}
 	return entity.JSONMap(value)
 }
+
+func formatMCPServerDate(date *time.Time) *string {
+	if date == nil {
+		return nil
+	}
+	formatted := date.Format(mcpServerDateFormat)
+	return &formatted
+}
+
+func paginateMCPServers(servers []*entity.MCPServer, page, pageSize int) []*entity.MCPServer {
+	if page == 0 || pageSize == 0 {
+		return servers
+	}
+
+	start := (page - 1) * pageSize
+	stop := page * pageSize
+	return sliceMCPServers(servers, start, stop)
+}
+
+func sliceMCPServers(servers []*entity.MCPServer, start, stop int) []*entity.MCPServer {
+	length := len(servers)
+	start = normalizeMCPServerSliceIndex(start, length)
+	stop = normalizeMCPServerSliceIndex(stop, length)
+	if stop < start {
+		return []*entity.MCPServer{}
+	}
+	return servers[start:stop]
+}
+
+func normalizeMCPServerSliceIndex(index, length int) int {
+	if index < 0 {
+		index += length
+	}
+	if index < 0 {
+		return 0
+	}
+	if index > length {
+		return length
+	}
+	return index
+}

internal/service/mcp_test.go

@@ -0,0 +1,65 @@
+//
+//  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 service
+
+import (
+	"fmt"
+	"testing"
+
+	"ragflow/internal/entity"
+)
+
+func TestPaginateMCPServersNegativeValuesMatchPythonSlice(t *testing.T) {
+	servers := makeMCPServers(13)
+
+	got := paginateMCPServers(servers, -1, -2)
+
+	if len(got) != 0 {
+		t.Fatalf("expected empty page for negative pagination, got %d servers", len(got))
+	}
+}
+
+func TestPaginateMCPServersKeepsUnpagedList(t *testing.T) {
+	servers := makeMCPServers(3)
+
+	got := paginateMCPServers(servers, 0, 0)
+
+	if len(got) != len(servers) {
+		t.Fatalf("expected unpaged list length %d, got %d", len(servers), len(got))
+	}
+}
+
+func TestPaginateMCPServersPositiveValues(t *testing.T) {
+	servers := makeMCPServers(5)
+
+	got := paginateMCPServers(servers, 2, 2)
+
+	if len(got) != 2 {
+		t.Fatalf("expected 2 servers, got %d", len(got))
+	}
+	if got[0].ID != "server-3" || got[1].ID != "server-4" {
+		t.Fatalf("expected second page servers, got %q and %q", got[0].ID, got[1].ID)
+	}
+}
+
+func makeMCPServers(count int) []*entity.MCPServer {
+	servers := make([]*entity.MCPServer, 0, count)
+	for i := 1; i <= count; i++ {
+		servers = append(servers, &entity.MCPServer{ID: fmt.Sprintf("server-%d", i)})
+	}
+	return servers
+}