diff --git a/alembic/versions/i1j2k3l4m5n6_add_equipment_sync.py b/alembic/versions/i1j2k3l4m5n6_add_equipment_sync.py
new file mode 100644
index 0000000..b47cc53
--- /dev/null
+++ b/alembic/versions/i1j2k3l4m5n6_add_equipment_sync.py
@@ -0,0 +1,111 @@
+"""add equipment sync schema
+
+Revision ID: i1j2k3l4m5n6
+Revises: h0c1d2e3f4g5
+Create Date: 2026-02-11 17:00:00.000000
+
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "i1j2k3l4m5n6"
+down_revision: Union[str, None] = "h0c1d2e3f4g5"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # Add columns to machines table
+    op.add_column("machines", sa.Column("external_id", sa.String(100), nullable=True))
+    op.add_column(
+        "machines",
+        sa.Column("source", sa.String(20), server_default="local", nullable=False),
+    )
+    op.add_column(
+        "machines",
+        sa.Column("sync_version", sa.Integer(), server_default="0", nullable=False),
+    )
+    op.add_column(
+        "machines",
+        sa.Column("last_synced_at", sa.TIMESTAMP(timezone=True), nullable=True),
+    )
+
+    # Create index on external_id
+    op.create_index("ix_machines_external_id", "machines", ["external_id"])
+
+    # Create partial unique constraint (external_id IS NOT NULL)
+    op.execute(
+        "CREATE UNIQUE INDEX uq_machines_tenant_external_id ON machines (tenant_id, external_id) WHERE external_id IS NOT NULL"
+    )
+
+    # Create machine_change_history table
+    op.create_table(
+        "machine_change_history",
+        sa.Column(
+            "id",
+            sa.dialects.postgresql.UUID(as_uuid=True),
+            primary_key=True,
+            server_default=sa.text("gen_random_uuid()"),
+        ),
+        sa.Column(
+            "tenant_id", sa.String(50), sa.ForeignKey("tenants.id"), nullable=False
+        ),
+        sa.Column(
+            "machine_id",
+            sa.dialects.postgresql.UUID(as_uuid=True),
+            sa.ForeignKey("machines.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column("field_name", sa.String(50), nullable=False),
+        sa.Column("old_value", sa.Text(), nullable=True),
+        sa.Column("new_value", sa.Text(), nullable=True),
+        sa.Column("change_source", sa.String(20), nullable=False),
+        sa.Column(
+            "changed_by",
+            sa.dialects.postgresql.UUID(as_uuid=True),
+            sa.ForeignKey("users.id"),
+            nullable=True,
+        ),
+        sa.Column(
+            "changed_at",
+            sa.TIMESTAMP(timezone=True),
+            nullable=False,
+            server_default=sa.text("now()"),
+        ),
+    )
+
+    # Create indexes on machine_change_history table
+    op.create_index(
+        "ix_machine_change_history_tenant_machine",
+        "machine_change_history",
+        ["tenant_id", "machine_id"],
+    )
+    op.create_index(
+        "ix_machine_change_history_tenant_date",
+        "machine_change_history",
+        ["tenant_id", "changed_at"],
+    )
+
+
+def downgrade() -> None:
+    # Drop indexes on machine_change_history table
+    op.drop_index("ix_machine_change_history_tenant_date")
+    op.drop_index("ix_machine_change_history_tenant_machine")
+
+    # Drop machine_change_history table
+    op.drop_table("machine_change_history")
+
+    # Drop partial unique constraint
+    op.execute("DROP INDEX IF EXISTS uq_machines_tenant_external_id")
+
+    # Drop index on machines table
+    op.drop_index("ix_machines_external_id", "machines")
+
+    # Drop columns from machines table
+    op.drop_column("machines", "last_synced_at")
+    op.drop_column("machines", "sync_version")
+    op.drop_column("machines", "source")
+    op.drop_column("machines", "external_id")
diff --git a/dashboard/app/[tenant]/machines/[id]/page.tsx b/dashboard/app/[tenant]/machines/[id]/page.tsx
index 459be7f..3eb5ddf 100644
--- a/dashboard/app/[tenant]/machines/[id]/page.tsx
+++ b/dashboard/app/[tenant]/machines/[id]/page.tsx
@@ -2,11 +2,25 @@
 
 import { useState, useCallback, useEffect } from 'react';
 import { useParams, useRouter } from 'next/navigation';
-import { useMachine, useEquipmentParts, useReplacements } from '@/lib/hooks';
+import { useMachine, useEquipmentParts, useReplacements, useMachineHistory } from '@/lib/hooks';
 import { useToast } from '@/lib/toast-context';
 import { api } from '@/lib/api';
 import type { EquipmentPart, PartReplacementLog } from '@/lib/types';
 
+const FIELD_LABELS: Record<string, string> = {
+  name: '설비명',
+  equipment_code: '설비 코드',
+  model: '모델명',
+  manufacturer: '제조사',
+  installation_date: '설치일',
+  location: '위치',
+  area: '구역',
+  criticality: '중요도',
+  rated_capacity: '정격 용량',
+  power_rating: '전력 사양',
+  description: '설명',
+};
+
 const LIFECYCLE_TYPES = [
   { value: 'hours', label: '시간 (Hours)' },
   { value: 'count', label: '횟수 (Count)' },
@@ -49,6 +63,7 @@ export default function MachineDetailPage() {
 
   const { machine, isLoading: machineLoading, mutate: mutateMachine } = useMachine(tenantId, machineId);
   const { parts, isLoading: partsLoading, mutate: mutateParts } = useEquipmentParts(tenantId, machineId);
+  const { history, isLoading: changeHistoryLoading } = useMachineHistory(tenantId, machineId);
   const { addToast } = useToast();
 
   const [showPartModal, setShowPartModal] = useState(false);
@@ -261,6 +276,44 @@ export default function MachineDetailPage() {
         </div>
       </div>
 
+      {machine.source === 'digital-twin' && (
+        <div className="sync-status-section">
+          <div className="section-header">
+            <h3 className="section-title">
+              <span className="material-symbols-outlined">cloud</span>
+              동기화 상태
+            </h3>
+          </div>
+          <div className="spec-grid">
+            <div className="spec-item">
+              <span className="spec-label">소스</span>
+              <span className="spec-value">
+                <span className="sync-badge">
+                  <span className="material-symbols-outlined">cloud</span>
+                  디지털 트윈
+                </span>
+              </span>
+            </div>
+            <div className="spec-item">
+              <span className="spec-label">동기화 버전</span>
+              <span className="spec-value">v{machine.sync_version}</span>
+            </div>
+            {machine.last_synced_at && (
+              <div className="spec-item">
+                <span className="spec-label">마지막 동기화</span>
+                <span className="spec-value">{new Date(machine.last_synced_at).toLocaleString('ko-KR')}</span>
+              </div>
+            )}
+            {machine.external_id && (
+              <div className="spec-item">
+                <span className="spec-label">외부 ID</span>
+                <span className="spec-value">{machine.external_id}</span>
+              </div>
+            )}
+          </div>
+        </div>
+      )}
+
       {(machine.manufacturer || machine.location || machine.rated_capacity || machine.power_rating || machine.description || machine.installation_date) && (
         <div className="section">
           <div className="section-header">
@@ -401,6 +454,54 @@ export default function MachineDetailPage() {
         )}
       </div>
 
+      <div className="section">
+        <div className="section-header">
+          <h3 className="section-title">
+            <span className="material-symbols-outlined">history</span>
+            변경 이력
+          </h3>
+        </div>
+        {historyLoading ? (
+          <div className="loading-sm">
+            <span className="material-symbols-outlined spinning">progress_activity</span>
+          </div>
+        ) : history.length === 0 ? (
+          <div className="empty-state-sm">
+            <span className="material-symbols-outlined">history</span>
+            <p>변경 이력이 없습니다.</p>
+          </div>
+        ) : (
+          <div className="part-table-wrap">
+            <table className="history-table">
+              <thead>
+                <tr>
+                  <th>시간</th>
+                  <th>필드</th>
+                  <th>이전 값</th>
+                  <th>새 값</th>
+                  <th>출처</th>
+                </tr>
+              </thead>
+              <tbody>
+                {history.map((h) => (
+                  <tr key={h.id}>
+                    <td>{new Date(h.changed_at).toLocaleString('ko-KR')}</td>
+                    <td>{FIELD_LABELS[h.field_name] || h.field_name}</td>
+                    <td>{h.old_value || '-'}</td>
+                    <td>{h.new_value || '-'}</td>
+                    <td>
+                      <span className={`history-source-badge ${h.change_source === 'sync' ? 'history-source-sync' : 'history-source-local'}`}>
+                        {h.change_source === 'sync' ? '동기화' : '로컬'}
+                      </span>
+                    </td>
+                  </tr>
+                ))}
+              </tbody>
+            </table>
+          </div>
+        )}
+      </div>
+
       {showPartModal && (
         <div className="modal-overlay" onClick={closePartModal}>
           <div className="modal-content modal-lg" onClick={(e) => e.stopPropagation()}>
@@ -643,7 +744,7 @@ export default function MachineDetailPage() {
               </button>
             </div>
             <div className="replacement-history">
-              {historyLoading ? (
+        {changeHistoryLoading ? (
                 <div className="loading-sm">
                   <span className="material-symbols-outlined spinning">progress_activity</span>
                 </div>
diff --git a/dashboard/app/[tenant]/page.tsx b/dashboard/app/[tenant]/page.tsx
index 88e514a..eef0778 100644
--- a/dashboard/app/[tenant]/page.tsx
+++ b/dashboard/app/[tenant]/page.tsx
@@ -6,7 +6,7 @@ import { useMachines } from '@/lib/hooks';
 import { useToast } from '@/lib/toast-context';
 import { api } from '@/lib/api';
 import { MachineList } from '@/components/MachineList';
-import type { Machine } from '@/lib/types';
+import type { Machine, ImportPreviewItem, ImportResult, SyncResult } from '@/lib/types';
 
 interface MachineForm {
   name: string;
@@ -30,6 +30,13 @@ export default function TenantDashboard() {
   const [submitting, setSubmitting] = useState(false);
   const [editTarget, setEditTarget] = useState<Machine | null>(null);
 
+  const [showImportModal, setShowImportModal] = useState(false);
+  const [importPreview, setImportPreview] = useState<ImportPreviewItem[]>([]);
+  const [selectedImports, setSelectedImports] = useState<Set<string>>(new Set());
+  const [syncing, setSyncing] = useState(false);
+  const [importing, setImporting] = useState(false);
+  const [importLoading, setImportLoading] = useState(false);
+
   const openCreate = useCallback(() => {
     setEditTarget(null);
     setForm(INITIAL_FORM);
@@ -98,8 +105,85 @@ export default function TenantDashboard() {
     }
   }, [tenantId, addToast, router]);
 
+  const openImportModal = useCallback(async () => {
+    setShowImportModal(true);
+    setImportLoading(true);
+    try {
+      const resp = await api.get<{ equipment: ImportPreviewItem[]; total: number }>(`/api/${tenantId}/machines/import/preview`);
+      setImportPreview(resp.equipment);
+      setSelectedImports(new Set());
+    } catch (err) {
+      addToast('디지털 트윈 데이터를 불러오는데 실패했습니다.', 'error');
+      setShowImportModal(false);
+    } finally {
+      setImportLoading(false);
+    }
+  }, [tenantId, addToast]);
+
+  const closeImportModal = useCallback(() => {
+    setShowImportModal(false);
+    setImportPreview([]);
+    setSelectedImports(new Set());
+  }, []);
+
+  const toggleImportSelection = useCallback((id: string) => {
+    setSelectedImports(prev => {
+      const next = new Set(prev);
+      if (next.has(id)) {
+        next.delete(id);
+      } else {
+        next.add(id);
+      }
+      return next;
+    });
+  }, []);
+
+  const toggleAllImports = useCallback(() => {
+    setSelectedImports(prev => {
+      const availableItems = importPreview.filter(item => !item.already_imported);
+      if (prev.size === availableItems.length) {
+        return new Set();
+      }
+      return new Set(availableItems.map(item => item.equipmentId));
+    });
+  }, [importPreview]);
+
+  const handleImport = useCallback(async () => {
+    if (selectedImports.size === 0) return;
+    setImporting(true);
+    try {
+      const result = await api.post<ImportResult>(`/api/${tenantId}/machines/import`, {
+        external_ids: Array.from(selectedImports)
+      });
+      addToast(`${result.imported_count}개 설비를 가져왔습니다.`, 'success');
+      mutate();
+      closeImportModal();
+    } catch (err) {
+      addToast('설비 가져오기에 실패했습니다.', 'error');
+    } finally {
+      setImporting(false);
+    }
+  }, [tenantId, selectedImports, mutate, addToast, closeImportModal]);
+
+  const handleSync = useCallback(async () => {
+    setSyncing(true);
+    try {
+      const result = await api.post<SyncResult>(`/api/${tenantId}/machines/sync`, {});
+      addToast(`동기화 완료: ${result.pull.synced_count}개 업데이트, ${result.push_count}개 전송`, 'success');
+      mutate();
+    } catch (err) {
+      addToast('동기화에 실패했습니다.', 'error');
+    } finally {
+      setSyncing(false);
+    }
+  }, [tenantId, mutate, addToast]);
+
   const handleDelete = useCallback(async (machine: Machine) => {
-    if (!confirm(`"${machine.name}" 설비를 삭제하시겠습니까?`)) return;
+    const message = machine.source === 'digital-twin'
+      ? `"${machine.name}"은(는) 디지털 트윈에서 가져온 설비입니다. 삭제하시겠습니까? (다음 동기화 시 다시 가져올 수 있습니다.)`
+      : `"${machine.name}" 설비를 삭제하시겠습니까?`;
+      
+    if (!confirm(message)) return;
     try {
       await api.delete(`/api/${tenantId}/machines/${machine.id}`);
       addToast('설비가 삭제되었습니다.', 'success');
@@ -125,10 +209,20 @@ export default function TenantDashboard() {
           <span className="material-symbols-outlined">precision_manufacturing</span>
           설비 관리
         </h2>
-        <button className="btn-primary" onClick={openCreate}>
-          <span className="material-symbols-outlined">add</span>
-          새 설비 등록
-        </button>
+        <div className="page-header-actions">
+          <button className={`btn-sync ${syncing ? 'sync-spinning' : ''}`} onClick={handleSync} disabled={syncing}>
+            <span className="material-symbols-outlined">sync</span>
+            동기화
+          </button>
+          <button className="btn-outline" onClick={openImportModal}>
+            <span className="material-symbols-outlined">cloud_download</span>
+            디지털 트윈에서 가져오기
+          </button>
+          <button className="btn-primary" onClick={openCreate}>
+            <span className="material-symbols-outlined">add</span>
+            새 설비 등록
+          </button>
+        </div>
       </div>
 
       {isLoading ? (
@@ -234,6 +328,68 @@ export default function TenantDashboard() {
           </div>
         </div>
       )}
+
+      {showImportModal && (
+        <div className="modal-overlay" onClick={closeImportModal}>
+          <div className="modal-content import-modal" onClick={e => e.stopPropagation()}>
+            <div className="modal-header">
+              <h3>디지털 트윈 설비 가져오기</h3>
+              <button className="modal-close" onClick={closeImportModal}>
+                <span className="material-symbols-outlined">close</span>
+              </button>
+            </div>
+            <div className="modal-body-form">
+              {importLoading ? (
+                <div className="loading">
+                  <span className="material-symbols-outlined spinning">progress_activity</span>
+                </div>
+              ) : (
+                <>
+                  <div className="import-select-all" onClick={toggleAllImports}>
+                    <span className="material-symbols-outlined">
+                      {selectedImports.size > 0 && selectedImports.size === importPreview.filter(i => !i.already_imported).length 
+                        ? 'check_box' 
+                        : 'check_box_outline_blank'}
+                    </span>
+                    전체 선택
+                  </div>
+                  <div className="import-list">
+                    {importPreview.map(item => (
+                      <div 
+                        key={item.equipmentId} 
+                        className={`import-item ${item.already_imported ? 'import-item-imported' : ''}`}
+                        onClick={() => !item.already_imported && toggleImportSelection(item.equipmentId)}
+                      >
+                        <input 
+                          type="checkbox" 
+                          className="import-item-checkbox"
+                          checked={selectedImports.has(item.equipmentId) || item.already_imported}
+                          disabled={item.already_imported}
+                          readOnly
+                        />
+                        <div className="import-item-info">
+                          <div className="import-item-name">{item.equipmentName}</div>
+                          <div className="import-item-code">{item.equipmentId} {item.model && `• ${item.model}`}</div>
+                        </div>
+                        {item.already_imported && (
+                          <span className="imported-badge">이미 가져옴</span>
+                        )}
+                      </div>
+                    ))}
+                  </div>
+                </>
+              )}
+            </div>
+            <div className="modal-actions">
+              <button className="btn-outline" onClick={closeImportModal} disabled={importing}>취소</button>
+              <button className="btn-primary" onClick={handleImport} disabled={importing || selectedImports.size === 0}>
+                {importing ? <span className="material-symbols-outlined spinning">progress_activity</span> : <span className="material-symbols-outlined">download</span>}
+                가져오기 ({selectedImports.size})
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
     </div>
   );
 }
diff --git a/dashboard/app/globals.css b/dashboard/app/globals.css
index 47f5a15..865f9bc 100644
--- a/dashboard/app/globals.css
+++ b/dashboard/app/globals.css
@@ -241,6 +241,7 @@ a {
 
 .btn-sm {
   padding: 6px 14px;
+  min-height: 36px;
   font-size: 12px;
 }
 
@@ -259,6 +260,7 @@ a {
   font-weight: 500;
   cursor: pointer;
   padding: 8px 12px;
+  min-height: 44px;
   border-radius: var(--md-radius-xl);
   transition: background var(--md-motion-quick);
   position: relative;
@@ -610,6 +612,7 @@ a {
   border: none;
   cursor: pointer;
   padding: 6px 8px;
+  min-height: 44px;
   border-radius: var(--md-radius-sm);
   color: var(--md-primary);
   transition: background var(--md-motion-quick);
@@ -653,6 +656,7 @@ a {
   align-items: center;
   gap: 6px;
   padding: 8px 16px;
+  min-height: 44px;
   background: none;
   border: none;
   border-radius: var(--md-radius-xl);
@@ -726,9 +730,17 @@ a {
   display: flex;
   align-items: center;
   justify-content: space-between;
+  gap: 12px;
+  flex-wrap: wrap;
   margin-bottom: 24px;
 }
 
+.page-header-actions {
+  display: flex;
+  gap: 8px;
+  flex-wrap: wrap;
+}
+
 .page-title {
   display: flex;
   align-items: center;
@@ -968,6 +980,7 @@ a {
 
 .detail-icon {
   font-size: 36px;
+  line-height: 1;
   color: var(--md-primary);
 }
 
@@ -991,6 +1004,10 @@ a {
   box-shadow: var(--md-elevation-1);
 }
 
+.section + .section {
+  margin-top: 20px;
+}
+
 .section-header {
   display: flex;
   align-items: center;
@@ -1010,6 +1027,7 @@ a {
 
 .section-title .material-symbols-outlined {
   font-size: 20px;
+  line-height: 1;
   color: var(--md-primary);
 }
 
@@ -2392,12 +2410,30 @@ a {
     display: none;
   }
 
+  .page-header {
+    gap: 8px;
+  }
+
+  .page-header-actions {
+    width: 100%;
+    justify-content: flex-end;
+  }
+
+  .page-title {
+    font-size: 18px;
+  }
+
   .btn-primary,
   .btn-outline {
     font-size: 13px;
     padding: 8px 14px;
   }
 
+  .btn-sync {
+    font-size: 13px;
+    padding: 8px 12px;
+  }
+
   .modal-content {
     margin: 8px;
     max-height: 95vh;
@@ -2508,3 +2544,401 @@ a {
   color: var(--md-on-surface-variant);
   border: 1px solid var(--md-outline-variant);
 }
+
+/* ===== Equipment Sync ===== */
+
+/* Sync badge on machine cards */
+.sync-badge {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  padding: 2px 8px;
+  border-radius: var(--md-radius-sm);
+  font-size: 11px;
+  font-weight: 600;
+  letter-spacing: 0.02em;
+  background: rgba(26, 115, 232, 0.08);
+  color: var(--md-primary);
+  border: 1px solid rgba(26, 115, 232, 0.15);
+}
+
+.sync-badge .material-symbols-outlined {
+  font-size: 14px;
+}
+
+/* Sync status section on machine detail page */
+.sync-status-section {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 12px 16px;
+  background: var(--md-surface-container-low);
+  border-radius: var(--md-radius);
+  margin-bottom: 16px;
+  font-size: 13px;
+  color: var(--md-on-surface-variant);
+  border: 1px solid var(--md-outline-variant);
+}
+
+.sync-status-section .material-symbols-outlined {
+  font-size: 20px;
+  color: var(--md-primary);
+}
+
+.sync-status-label {
+  font-weight: 500;
+  color: var(--md-on-surface);
+}
+
+.sync-status-value {
+  color: var(--md-on-surface-variant);
+}
+
+.sync-status-divider {
+  width: 1px;
+  height: 20px;
+  background: var(--md-outline-variant);
+}
+
+/* Info tooltip for upstream-managed fields */
+.field-info-tooltip {
+  position: relative;
+  display: inline-flex;
+  align-items: center;
+  margin-left: 4px;
+  cursor: help;
+}
+
+.field-info-tooltip .material-symbols-outlined {
+  font-size: 16px;
+  color: var(--md-on-surface-variant);
+  opacity: 0.6;
+}
+
+.field-info-tooltip:hover .material-symbols-outlined {
+  opacity: 1;
+  color: var(--md-primary);
+}
+
+.field-info-tooltip-text {
+  display: none;
+  position: absolute;
+  bottom: calc(100% + 8px);
+  left: 50%;
+  transform: translateX(-50%);
+  padding: 8px 12px;
+  background: var(--md-on-surface);
+  color: var(--md-surface);
+  font-size: 12px;
+  border-radius: var(--md-radius-xs);
+  white-space: nowrap;
+  z-index: 100;
+  box-shadow: var(--md-elevation-2);
+}
+
+.field-info-tooltip:hover .field-info-tooltip-text {
+  display: block;
+}
+
+/* Import modal - extends .modal-content */
+.import-modal {
+  max-width: 640px;
+}
+
+.import-list {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  max-height: 400px;
+  overflow-y: auto;
+  padding: 4px 0;
+}
+
+.import-item {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 10px 16px;
+  border-radius: var(--md-radius-sm);
+  cursor: pointer;
+  transition: background var(--md-motion-standard);
+}
+
+.import-item:hover {
+  background: var(--md-surface-container);
+}
+
+.import-item-checkbox {
+  width: 18px;
+  height: 18px;
+  accent-color: var(--md-primary);
+}
+
+.import-item-info {
+  flex: 1;
+  min-width: 0;
+}
+
+.import-item-name {
+  font-size: 14px;
+  font-weight: 500;
+  color: var(--md-on-surface);
+}
+
+.import-item-code {
+  font-size: 12px;
+  color: var(--md-on-surface-variant);
+}
+
+.import-item-imported {
+  opacity: 0.5;
+  cursor: default;
+}
+
+.import-item-imported .import-item-checkbox {
+  pointer-events: none;
+}
+
+.imported-badge {
+  display: inline-flex;
+  align-items: center;
+  padding: 2px 6px;
+  border-radius: var(--md-radius-xs);
+  font-size: 10px;
+  font-weight: 600;
+  background: var(--md-surface-container-highest);
+  color: var(--md-on-surface-variant);
+}
+
+/* History table */
+.history-section {
+  margin-top: 24px;
+}
+
+.history-section-title {
+  font-size: 16px;
+  font-weight: 600;
+  color: var(--md-on-surface);
+  margin-bottom: 12px;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.history-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 13px;
+}
+
+.history-table th {
+  text-align: left;
+  padding: 8px 12px;
+  font-weight: 600;
+  color: var(--md-on-surface-variant);
+  border-bottom: 2px solid var(--md-outline-variant);
+  font-size: 12px;
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+}
+
+.history-table td {
+  padding: 8px 12px;
+  border-bottom: 1px solid var(--md-surface-container-high);
+  color: var(--md-on-surface);
+  vertical-align: top;
+}
+
+.history-table tr:hover td {
+  background: var(--md-surface-container-low);
+}
+
+.history-source-badge {
+  display: inline-flex;
+  align-items: center;
+  padding: 2px 6px;
+  border-radius: var(--md-radius-xs);
+  font-size: 10px;
+  font-weight: 600;
+}
+
+.history-source-local {
+  background: rgba(26, 115, 232, 0.1);
+  color: var(--md-primary);
+}
+
+.history-source-sync {
+  background: rgba(30, 142, 62, 0.1);
+  color: var(--md-success);
+}
+
+.history-old-value {
+  text-decoration: line-through;
+  color: var(--md-on-surface-variant);
+  opacity: 0.7;
+}
+
+.history-new-value {
+  font-weight: 500;
+}
+
+/* Sync result notification banner */
+.sync-result-banner {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 12px 16px;
+  border-radius: var(--md-radius);
+  margin-bottom: 16px;
+  animation: modal-fade-in 200ms ease-out;
+}
+
+.sync-result-banner-success {
+  background: rgba(30, 142, 62, 0.08);
+  border: 1px solid rgba(30, 142, 62, 0.2);
+  color: var(--md-success);
+}
+
+.sync-result-banner-error {
+  background: rgba(217, 48, 37, 0.08);
+  border: 1px solid rgba(217, 48, 37, 0.2);
+  color: var(--md-error);
+}
+
+.sync-result-banner .material-symbols-outlined {
+  font-size: 20px;
+}
+
+.sync-result-banner-text {
+  flex: 1;
+  font-size: 13px;
+  font-weight: 500;
+}
+
+.sync-result-banner-close {
+  background: none;
+  border: none;
+  cursor: pointer;
+  color: inherit;
+  opacity: 0.6;
+  padding: 4px;
+}
+
+.sync-result-banner-close:hover {
+  opacity: 1;
+}
+
+/* Sync action buttons group */
+.sync-btn-group {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.btn-sync {
+  display: inline-flex;
+  align-items: center;
+  gap: 6px;
+  padding: 8px 16px;
+  border-radius: var(--md-radius-full);
+  font-size: 13px;
+  font-weight: 500;
+  border: 1px solid var(--md-outline-variant);
+  background: var(--md-surface);
+  color: var(--md-on-surface);
+  cursor: pointer;
+  transition: all var(--md-motion-standard);
+}
+
+.btn-sync:hover {
+  background: var(--md-surface-container);
+  border-color: var(--md-outline);
+}
+
+.btn-sync:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+}
+
+.btn-sync .material-symbols-outlined {
+  font-size: 18px;
+}
+
+.btn-sync-primary {
+  background: var(--md-primary);
+  color: var(--md-on-primary);
+  border-color: var(--md-primary);
+}
+
+.btn-sync-primary:hover {
+  background: var(--md-primary-dark);
+  border-color: var(--md-primary-dark);
+}
+
+/* Sync spinner */
+@keyframes sync-spin {
+  from { transform: rotate(0deg); }
+  to { transform: rotate(360deg); }
+}
+
+.sync-spinning .material-symbols-outlined {
+  animation: sync-spin 1s linear infinite;
+}
+
+/* Select all / deselect all in import modal */
+.import-select-all {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  padding: 8px 16px;
+  font-size: 13px;
+  color: var(--md-primary);
+  font-weight: 500;
+  cursor: pointer;
+  border-bottom: 1px solid var(--md-outline-variant);
+}
+
+.import-summary {
+  padding: 8px 16px;
+  font-size: 12px;
+  color: var(--md-on-surface-variant);
+  border-top: 1px solid var(--md-outline-variant);
+}
+
+/* Load more button for history */
+.history-load-more {
+  display: flex;
+  justify-content: center;
+  padding: 12px;
+}
+
+.history-load-more button {
+  padding: 8px 24px;
+  border-radius: var(--md-radius-full);
+  border: 1px solid var(--md-outline-variant);
+  background: var(--md-surface);
+  color: var(--md-primary);
+  font-size: 13px;
+  font-weight: 500;
+  cursor: pointer;
+  transition: background var(--md-motion-standard);
+}
+
+.history-load-more button:hover {
+  background: var(--md-surface-container);
+}
+
+/* Empty state for history */
+.history-empty {
+  text-align: center;
+  padding: 32px;
+  color: var(--md-on-surface-variant);
+  font-size: 14px;
+}
+
+.history-empty .material-symbols-outlined {
+  font-size: 40px;
+  opacity: 0.4;
+  margin-bottom: 8px;
+  display: block;
+}
diff --git a/dashboard/components/MachineList.tsx b/dashboard/components/MachineList.tsx
index 0f2bfaa..ab05a6b 100644
--- a/dashboard/components/MachineList.tsx
+++ b/dashboard/components/MachineList.tsx
@@ -113,16 +113,24 @@ export function MachineList({ machines, tenantId, onEdit, onDelete, onBatchInspe
                   className="machine-card-body"
                   onClick={() => router.push(`/${tenantId}/machines/${machine.id}`)}
                 >
-                  <div className="machine-card-top">
-                    <div className="machine-card-icon">
-                      <span className="material-symbols-outlined">precision_manufacturing</span>
+                    <div className="machine-card-top">
+                      <div className="machine-card-icon">
+                        <span className="material-symbols-outlined">precision_manufacturing</span>
+                      </div>
+                      <div style={{ display: 'flex', gap: '4px' }}>
+                        {machine.source === 'digital-twin' && (
+                          <span className="sync-badge">
+                            <span className="material-symbols-outlined">cloud</span>
+                            동기화
+                          </span>
+                        )}
+                        {machine.criticality && (
+                          <span className={`machine-badge ${getBadgeClass(machine.criticality)}`}>
+                            {getBadgeText(machine.criticality)}
+                          </span>
+                        )}
+                      </div>
                     </div>
-                    {machine.criticality && (
-                      <span className={`machine-badge ${getBadgeClass(machine.criticality)}`}>
-                        {getBadgeText(machine.criticality)}
-                      </span>
-                    )}
-                  </div>
                   
                   <div className="machine-card-info">
                     <h3 className="machine-card-name">{machine.name}</h3>
diff --git a/dashboard/lib/hooks.ts b/dashboard/lib/hooks.ts
index 9ab9105..30605e3 100644
--- a/dashboard/lib/hooks.ts
+++ b/dashboard/lib/hooks.ts
@@ -1,6 +1,6 @@
 import useSWR from 'swr';
 import { fetcher, getTenantUrl } from './api';
-import type { Tenant, Machine, MachineDetail, EquipmentPart, InspectionTemplate, InspectionSession, PartReplacementLog, Alarm, AlarmSummary } from './types';
+import type { Tenant, Machine, MachineDetail, EquipmentPart, InspectionTemplate, InspectionSession, PartReplacementLog, Alarm, AlarmSummary, ChangeHistoryItem } from './types';
 
 export function useTenants() {
   const { data, error, isLoading, mutate } = useSWR<{ tenants: Tenant[] }>(
@@ -180,6 +180,23 @@ export function useInspections(tenantId?: string, status?: string, templateId?:
   };
 }
 
+export function useMachineHistory(tenantId?: string, machineId?: string) {
+  const url = tenantId && machineId ? `/api/${tenantId}/machines/${machineId}/history` : null;
+  const { data, error, isLoading, mutate } = useSWR<{ history: ChangeHistoryItem[]; total: number }>(
+    url,
+    fetcher,
+    { dedupingInterval: 2000 },
+  );
+
+  return {
+    history: data?.history || [],
+    total: data?.total || 0,
+    error,
+    isLoading,
+    mutate,
+  };
+}
+
 export function useInspection(tenantId?: string, inspectionId?: string) {
   const url = tenantId && inspectionId ? `/api/${tenantId}/inspections/${inspectionId}` : null;
   const { data, error, isLoading, mutate } = useSWR<InspectionSession>(
diff --git a/dashboard/lib/types.ts b/dashboard/lib/types.ts
index c118d74..832b5be 100644
--- a/dashboard/lib/types.ts
+++ b/dashboard/lib/types.ts
@@ -37,6 +37,10 @@ export interface Machine {
   rated_capacity: string | null;
   power_rating: string | null;
   description: string | null;
+  source: string | null;
+  external_id: string | null;
+  sync_version: number;
+  last_synced_at: string | null;
   parts_count: number;
   created_at: string | null;
   updated_at: string | null;
@@ -72,6 +76,42 @@ export interface MachineDetail extends Machine {
   parts: EquipmentPart[];
 }
 
+export interface ChangeHistoryItem {
+  id: string;
+  field_name: string;
+  old_value: string | null;
+  new_value: string | null;
+  change_source: string;
+  changed_by: string | null;
+  changed_at: string;
+}
+
+export interface SyncResult {
+  pull: {
+    synced_count: number;
+    fields_updated: number;
+    errors: string[];
+  };
+  push_count: number;
+  push_errors: string[];
+}
+
+export interface ImportResult {
+  imported_count: number;
+  skipped_count: number;
+  errors: string[];
+}
+
+export interface ImportPreviewItem {
+  id: string;
+  equipmentName: string;
+  equipmentId: string;
+  model: string | null;
+  manufacturer: string | null;
+  location: string | null;
+  already_imported: boolean;
+}
+
 export interface InspectionTemplateItem {
   id: string;
   template_id: string;
diff --git a/docker-compose.dev.yml b/docker-compose.dev.yml
new file mode 100644
index 0000000..cde7012
--- /dev/null
+++ b/docker-compose.dev.yml
@@ -0,0 +1,59 @@
+version: '3.8'
+
+services:
+  api:
+    build:
+      context: .
+      dockerfile: Containerfile.backend
+    container_name: factoryops-dev-api
+    restart: unless-stopped
+    networks:
+      - default
+      - digital-twin
+    ports:
+      - "8000:8000"
+    environment:
+      - PYTHONPATH=/app
+      - PYTHONUNBUFFERED=1
+      # 원격 DB (IDC 배포서버)
+      - DATABASE_URL=postgresql+asyncpg://factoryops:factoryops@211.115.91.141:8200/factoryops_v2
+      - JWT_SECRET_KEY=factoryops-v2-dev-secret-key-2026
+      - CORS_ORIGINS=http://localhost:3100,http://127.0.0.1:3100
+      - DIGITAL_TWIN_API_URL=http://digital-twin-web-backend:4001
+    volumes:
+      # 소스 마운트 → 핫 리로드
+      - ./main.py:/app/main.py:ro
+      - ./src:/app/src:ro
+      - ./alembic:/app/alembic:ro
+      - ./alembic.ini:/app/alembic.ini:ro
+      - ./scripts:/app/scripts:ro
+    # uvicorn --reload 로 실행 (개발용)
+    command: ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000", "--reload"]
+
+  dashboard:
+    image: node:20-alpine
+    container_name: factoryops-dev-dashboard
+    restart: unless-stopped
+    working_dir: /app
+    ports:
+      - "3100:3100"
+    environment:
+      - NEXT_PUBLIC_API_URL=http://localhost:8000
+      - NEXT_TELEMETRY_DISABLED=1
+    volumes:
+      - ./dashboard:/app
+      - dashboard_node_modules:/app/node_modules
+    # npm install 후 dev 서버 실행
+    command: ["sh", "-c", "npm install && npm run dev"]
+    depends_on:
+      - api
+
+volumes:
+  dashboard_node_modules:
+
+networks:
+  default:
+    name: factoryops-dev-network
+  digital-twin:
+    external: true
+    name: digital-twin-web_default
diff --git a/main.py b/main.py
index 7b099fd..14275ff 100644
--- a/main.py
+++ b/main.py
@@ -20,6 +20,7 @@ from src.auth.password import hash_password
 from src.tenant import manager as tenant_manager
 from src.tenant.manager import TenantNotFoundError, InvalidTenantIdError
 from src.api.machines import router as machines_router
+from src.api.equipment_sync import router as equipment_sync_router
 from src.api.equipment_parts import router as equipment_parts_router
 from src.api.templates import router as templates_router
 from src.api.inspections import router as inspections_router
@@ -53,6 +54,7 @@ app.add_middleware(
 app.include_router(auth_router)
 app.include_router(auth_admin_router)
 app.include_router(machines_router)
+app.include_router(equipment_sync_router)
 app.include_router(equipment_parts_router)
 app.include_router(templates_router)
 app.include_router(inspections_router)
diff --git a/src/api/equipment_sync.py b/src/api/equipment_sync.py
new file mode 100644
index 0000000..3b16340
--- /dev/null
+++ b/src/api/equipment_sync.py
@@ -0,0 +1,108 @@
+import os
+from typing import Optional, List
+
+from fastapi import APIRouter, HTTPException, Depends, Path
+from pydantic import BaseModel
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from src.database.config import get_db
+from src.database.models import Machine
+from src.auth.models import TokenData
+from src.auth.dependencies import require_auth, verify_tenant_access
+from src.services.equipment_sync import EquipmentSyncService
+
+router = APIRouter(prefix="/api/{tenant_id}/machines", tags=["equipment-sync"])
+
+
+class ImportRequest(BaseModel):
+    external_ids: Optional[List[str]] = None
+
+
+class ImportPreviewItem(BaseModel):
+    id: str
+    equipmentName: str
+    equipmentId: str
+    model: Optional[str] = None
+    manufacturer: Optional[str] = None
+    location: Optional[str] = None
+    already_imported: bool = False
+
+
+def _check_sync_configured():
+    if not os.getenv("DIGITAL_TWIN_API_URL"):
+        raise HTTPException(
+            status_code=503,
+            detail="DIGITAL_TWIN_API_URL이 설정되지 않았습니다. 디지털 트윈 연동이 비활성 상태입니다.",
+        )
+
+
+@router.post("/sync")
+async def sync_machines(
+    tenant_id: str = Path(...),
+    current_user: TokenData = Depends(require_auth),
+    db: AsyncSession = Depends(get_db),
+):
+    verify_tenant_access(tenant_id, current_user)
+    _check_sync_configured()
+
+    svc = EquipmentSyncService(db, tenant_id)
+    result = await svc.sync()
+    return result.model_dump()
+
+
+@router.post("/import")
+async def import_machines(
+    body: ImportRequest,
+    tenant_id: str = Path(...),
+    current_user: TokenData = Depends(require_auth),
+    db: AsyncSession = Depends(get_db),
+):
+    verify_tenant_access(tenant_id, current_user)
+    _check_sync_configured()
+
+    svc = EquipmentSyncService(db, tenant_id)
+    result = await svc.import_equipment(body.external_ids)
+    return result.model_dump()
+
+
+@router.get("/import/preview")
+async def import_preview(
+    tenant_id: str = Path(...),
+    current_user: TokenData = Depends(require_auth),
+    db: AsyncSession = Depends(get_db),
+):
+    verify_tenant_access(tenant_id, current_user)
+    _check_sync_configured()
+
+    svc = EquipmentSyncService(db, tenant_id)
+    remote_list = await svc.fetch_remote_equipment()
+
+    existing_stmt = select(Machine.external_id).where(
+        Machine.tenant_id == tenant_id,
+        Machine.source == "digital-twin",
+        Machine.external_id.isnot(None),
+    )
+    existing_ids = set()
+    result = await db.execute(existing_stmt)
+    for row in result.scalars().all():
+        existing_ids.add(str(row))
+
+    preview = []
+    for eq in remote_list:
+        remote_id = str(eq.get("id", ""))
+        if not remote_id:
+            continue
+        preview.append(
+            ImportPreviewItem(
+                id=remote_id,
+                equipmentName=eq.get("name", eq.get("equipmentName", "")),
+                equipmentId=eq.get("equipmentId", eq.get("equipment_code", "")),
+                model=eq.get("model"),
+                manufacturer=eq.get("manufacturer"),
+                location=eq.get("location"),
+                already_imported=remote_id in existing_ids,
+            )
+        )
+
+    return {"equipment": preview, "total": len(preview)}
diff --git a/src/api/machines.py b/src/api/machines.py
index 6b874e6..63def9a 100644
--- a/src/api/machines.py
+++ b/src/api/machines.py
@@ -1,7 +1,7 @@
 from typing import List, Optional
 from uuid import UUID
 
-from fastapi import APIRouter, HTTPException, Depends, Path
+from fastapi import APIRouter, HTTPException, Depends, Path, Query
 from pydantic import BaseModel
 from sqlalchemy import select, func, update
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -10,6 +10,7 @@ from sqlalchemy.orm import selectinload
 from src.database.config import get_db
 from src.database.models import (
     Machine,
+    MachineChangeHistory,
     EquipmentPart,
     InspectionTemplate,
     InspectionTemplateItem,
@@ -66,6 +67,10 @@ class MachineResponse(BaseModel):
     rated_capacity: Optional[str] = None
     power_rating: Optional[str] = None
     description: Optional[str] = None
+    source: Optional[str] = None
+    external_id: Optional[str] = None
+    sync_version: int = 0
+    last_synced_at: Optional[str] = None
     parts_count: int = 0
     created_at: Optional[str] = None
     updated_at: Optional[str] = None
@@ -98,6 +103,10 @@ def _machine_to_response(m: Machine, parts_count: int = 0) -> MachineResponse:
         rated_capacity=str(m.rated_capacity) if m.rated_capacity else None,
         power_rating=str(m.power_rating) if m.power_rating else None,
         description=str(m.description) if m.description else None,
+        source=str(m.source) if m.source else "local",
+        external_id=str(m.external_id) if m.external_id else None,
+        sync_version=int(m.sync_version) if m.sync_version else 0,
+        last_synced_at=_format_ts(m.last_synced_at),
         parts_count=parts_count,
         created_at=_format_ts(m.created_at),
         updated_at=_format_ts(m.updated_at),
@@ -226,6 +235,10 @@ async def get_machine(
         rated_capacity=str(machine.rated_capacity) if machine.rated_capacity else None,
         power_rating=str(machine.power_rating) if machine.power_rating else None,
         description=str(machine.description) if machine.description else None,
+        source=str(machine.source) if machine.source else "local",
+        external_id=str(machine.external_id) if machine.external_id else None,
+        sync_version=int(machine.sync_version) if machine.sync_version else 0,
+        last_synced_at=_format_ts(machine.last_synced_at),
         parts_count=len(active_parts),
         parts=parts_data,
         created_at=_format_ts(machine.created_at),
@@ -253,6 +266,27 @@ async def update_machine(
     if not machine:
         raise HTTPException(status_code=404, detail="설비를 찾을 수 없습니다.")
 
+    changes: list[tuple[str, str | None, str | None]] = []
+    update_fields = body.model_dump(exclude_unset=True)
+
+    for field, new_val in update_fields.items():
+        if field == "criticality" and new_val not in VALID_CRITICALITIES:
+            raise HTTPException(
+                status_code=400,
+                detail=f"criticality는 {', '.join(VALID_CRITICALITIES)} 중 하나여야 합니다.",
+            )
+
+        old_raw = getattr(machine, field, None)
+        old_val = (
+            old_raw.isoformat()
+            if hasattr(old_raw, "isoformat")
+            else (str(old_raw) if old_raw is not None else None)
+        )
+        new_val_str = str(new_val) if new_val is not None else None
+
+        if old_val != new_val_str:
+            changes.append((field, old_val, new_val_str))
+
     if body.name is not None:
         machine.name = body.name
     if body.equipment_code is not None:
@@ -275,11 +309,6 @@ async def update_machine(
     if body.area is not None:
         machine.area = body.area
     if body.criticality is not None:
-        if body.criticality not in VALID_CRITICALITIES:
-            raise HTTPException(
-                status_code=400,
-                detail=f"criticality는 {', '.join(VALID_CRITICALITIES)} 중 하나여야 합니다.",
-            )
         machine.criticality = body.criticality
     if body.rated_capacity is not None:
         machine.rated_capacity = body.rated_capacity
@@ -288,9 +317,39 @@ async def update_machine(
     if body.description is not None:
         machine.description = body.description
 
+    from datetime import datetime as dt_import, timezone as tz
+
+    now = dt_import.now(tz.utc)
+    for field_name, old_v, new_v in changes:
+        history = MachineChangeHistory(
+            tenant_id=tenant_id,
+            machine_id=machine.id,
+            field_name=field_name,
+            old_value=old_v,
+            new_value=new_v,
+            change_source="local",
+            changed_by=current_user.user_id,
+            changed_at=now,
+        )
+        db.add(history)
+
     await db.commit()
     await db.refresh(machine)
 
+    if machine.source == "digital-twin" and machine.external_id and changes:
+        try:
+            from src.services.equipment_sync import EquipmentSyncService
+
+            sync_svc = EquipmentSyncService(db, tenant_id)
+            await sync_svc.push_to_remote(machine.id)
+        except Exception:
+            import logging
+
+            logging.getLogger(__name__).warning(
+                f"Failed to push changes to digital-twin for machine {machine.id}",
+                exc_info=True,
+            )
+
     return _machine_to_response(machine)
 
 
@@ -350,4 +409,64 @@ async def delete_machine(
     await db.delete(machine)
     await db.commit()
 
-    return {"status": "success", "message": "설비가 삭제되었습니다."}
+    response = {"status": "success", "message": "설비가 삭제되었습니다."}
+    if machine.source == "digital-twin":
+        response["warning"] = (
+            "디지털 트윈에서 가져온 설비가 삭제되었습니다. 다음 동기화 시 다시 가져올 수 있습니다."
+        )
+    return response
+
+
+class ChangeHistoryItem(BaseModel):
+    id: str
+    field_name: str
+    old_value: Optional[str]
+    new_value: Optional[str]
+    change_source: str
+    changed_by: Optional[str]
+    changed_at: str
+
+
+@router.get("/{machine_id}/history")
+async def get_machine_history(
+    tenant_id: str = Path(...),
+    machine_id: UUID = Path(...),
+    limit: int = Query(50, ge=1, le=200),
+    offset: int = Query(0, ge=0),
+    current_user: TokenData = Depends(require_auth),
+    db: AsyncSession = Depends(get_db),
+):
+    verify_tenant_access(tenant_id, current_user)
+
+    count_stmt = select(func.count(MachineChangeHistory.id)).where(
+        MachineChangeHistory.tenant_id == tenant_id,
+        MachineChangeHistory.machine_id == machine_id,
+    )
+    total = (await db.execute(count_stmt)).scalar() or 0
+
+    stmt = (
+        select(MachineChangeHistory)
+        .where(
+            MachineChangeHistory.tenant_id == tenant_id,
+            MachineChangeHistory.machine_id == machine_id,
+        )
+        .order_by(MachineChangeHistory.changed_at.desc())
+        .offset(offset)
+        .limit(limit)
+    )
+    rows = (await db.execute(stmt)).scalars().all()
+
+    history = [
+        ChangeHistoryItem(
+            id=str(h.id),
+            field_name=str(h.field_name),
+            old_value=str(h.old_value) if h.old_value else None,
+            new_value=str(h.new_value) if h.new_value else None,
+            change_source=str(h.change_source),
+            changed_by=str(h.changed_by) if h.changed_by else None,
+            changed_at=_format_ts(h.changed_at) or "",
+        )
+        for h in rows
+    ]
+
+    return {"history": history, "total": total}
diff --git a/src/database/models.py b/src/database/models.py
index 0295e00..c66a4c2 100644
--- a/src/database/models.py
+++ b/src/database/models.py
@@ -70,6 +70,10 @@ class Machine(Base):
     rated_capacity = Column(String(100), nullable=True)
     power_rating = Column(String(100), nullable=True)
     description = Column(Text, nullable=True)
+    external_id = Column(String(100), nullable=True, index=True)
+    source = Column(String(20), default="local")  # local | digital-twin
+    sync_version = Column(Integer, default=0)
+    last_synced_at = Column(TIMESTAMP(timezone=True), nullable=True)
     created_at = Column(TIMESTAMP(timezone=True), default=utcnow)
     updated_at = Column(TIMESTAMP(timezone=True), default=utcnow, onupdate=utcnow)
 
@@ -77,11 +81,46 @@ class Machine(Base):
     parts = relationship(
         "EquipmentPart", back_populates="machine", cascade="all, delete-orphan"
     )
+    change_history = relationship(
+        "MachineChangeHistory",
+        back_populates="machine",
+        cascade="all, delete-orphan",
+    )
 
     __table_args__ = (
         Index("ix_machines_tenant_id", "tenant_id"),
         Index("ix_machines_tenant_area", "tenant_id", "area"),
         Index("ix_machines_tenant_criticality", "tenant_id", "criticality"),
+        UniqueConstraint(
+            "tenant_id", "external_id", name="uq_machines_tenant_external_id"
+        ),
+    )
+
+
+class MachineChangeHistory(Base):
+    __tablename__ = "machine_change_history"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    tenant_id = Column(String(50), ForeignKey("tenants.id"), nullable=False)
+    machine_id = Column(
+        UUID(as_uuid=True),
+        ForeignKey("machines.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    field_name = Column(String(50), nullable=False)
+    old_value = Column(Text, nullable=True)
+    new_value = Column(Text, nullable=True)
+    change_source = Column(String(20), nullable=False)  # local | sync
+    changed_by = Column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=True)
+    changed_at = Column(TIMESTAMP(timezone=True), nullable=False, default=utcnow)
+
+    tenant = relationship("Tenant")
+    machine = relationship("Machine", back_populates="change_history")
+    changed_by_user = relationship("User")
+
+    __table_args__ = (
+        Index("ix_machine_change_history_tenant_machine", "tenant_id", "machine_id"),
+        Index("ix_machine_change_history_tenant_date", "tenant_id", "changed_at"),
     )
 
 
diff --git a/src/services/equipment_sync.py b/src/services/equipment_sync.py
new file mode 100644
index 0000000..90e03e4
--- /dev/null
+++ b/src/services/equipment_sync.py
@@ -0,0 +1,370 @@
+import os
+import logging
+from datetime import datetime, timezone
+from typing import Optional
+from uuid import UUID
+
+import httpx
+from pydantic import BaseModel
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from src.database.models import Machine, MachineChangeHistory
+
+logger = logging.getLogger(__name__)
+
+UPSTREAM_FIELDS = {
+    "name",
+    "equipment_code",
+    "model",
+    "manufacturer",
+    "installation_date",
+    "location",
+    "rated_capacity",
+    "power_rating",
+}
+LOCAL_FIELDS = {"criticality", "area", "description"}
+
+FIELD_MAPPING = {
+    "name": "name",
+    "equipmentId": "equipment_code",
+    "model": "model",
+    "manufacturer": "manufacturer",
+    "installationDate": "installation_date",
+    "location": "location",
+    "capacity": "rated_capacity",
+    "powerConsumption": "power_rating",
+    "description": "description",
+}
+
+
+class ImportResult(BaseModel):
+    imported_count: int = 0
+    skipped_count: int = 0
+    errors: list[str] = []
+
+
+class PullResult(BaseModel):
+    synced_count: int = 0
+    fields_updated: int = 0
+    errors: list[str] = []
+
+
+class PushResult(BaseModel):
+    success: bool = True
+    fields_pushed: list[str] = []
+    error: Optional[str] = None
+
+
+class SyncResult(BaseModel):
+    pull: PullResult
+    push_count: int = 0
+    push_errors: list[str] = []
+
+
+class EquipmentSyncService:
+    def __init__(self, db: AsyncSession, tenant_id: str):
+        self.db = db
+        self.tenant_id = tenant_id
+        self.api_url = os.getenv("DIGITAL_TWIN_API_URL", "")
+        self.api_key = os.getenv("DIGITAL_TWIN_API_KEY", "")
+
+    def _get_headers(self) -> dict:
+        headers = {"Content-Type": "application/json"}
+        if self.api_key:
+            headers["Authorization"] = f"Bearer {self.api_key}"
+        return headers
+
+    def _http_client(self) -> httpx.AsyncClient:
+        return httpx.AsyncClient(
+            base_url=self.api_url,
+            headers=self._get_headers(),
+            timeout=30.0,
+        )
+
+    async def fetch_remote_equipment(self) -> list[dict]:
+        if not self.api_url:
+            return []
+        try:
+            async with self._http_client() as client:
+                resp = await client.get("/api/v1/aas/equipment")
+                resp.raise_for_status()
+                data = resp.json()
+                if isinstance(data, list):
+                    return data
+                if isinstance(data, dict):
+                    # digital-twin 응답: { success, data: { equipment: [...] } }
+                    inner = data.get("data", data)
+                    if isinstance(inner, dict):
+                        return inner.get("equipment", inner.get("data", []))
+                    if isinstance(inner, list):
+                        return inner
+                return []
+        except Exception as e:
+            logger.error(f"Failed to fetch remote equipment: {e}")
+            return []
+
+    def _map_remote_to_local(self, remote: dict) -> dict:
+        mapped = {}
+        for remote_key, local_key in FIELD_MAPPING.items():
+            val = remote.get(remote_key)
+            if val is not None:
+                mapped[local_key] = str(val) if val else None
+        location = remote.get("location", "")
+        if location and " " in str(location):
+            parts = str(location).split(" ")
+            mapped["area"] = parts[0] if parts else None
+        return mapped
+
+    async def import_equipment(
+        self, external_ids: Optional[list[str]] = None
+    ) -> ImportResult:
+        result = ImportResult()
+        remote_list = await self.fetch_remote_equipment()
+        if not remote_list:
+            result.errors.append("디지털 트윈에서 설비 데이터를 가져올 수 없습니다.")
+            return result
+
+        for eq in remote_list:
+            remote_id = str(eq.get("id", ""))
+            if not remote_id:
+                continue
+            if external_ids and remote_id not in external_ids:
+                continue
+
+            existing = await self.db.execute(
+                select(Machine).where(
+                    Machine.tenant_id == self.tenant_id,
+                    Machine.external_id == remote_id,
+                )
+            )
+            if existing.scalar_one_or_none():
+                result.skipped_count += 1
+                continue
+
+            try:
+                mapped = self._map_remote_to_local(eq)
+                install_dt = None
+                raw_date = mapped.get("installation_date")
+                if raw_date:
+                    try:
+                        install_dt = datetime.fromisoformat(
+                            raw_date.replace("Z", "+00:00")
+                        )
+                    except (ValueError, AttributeError):
+                        pass
+
+                machine = Machine(
+                    tenant_id=self.tenant_id,
+                    name=mapped.get("name", f"Equipment-{remote_id[:8]}"),
+                    equipment_code=mapped.get("equipment_code", ""),
+                    model=mapped.get("model"),
+                    manufacturer=mapped.get("manufacturer"),
+                    installation_date=install_dt,
+                    location=mapped.get("location"),
+                    area=mapped.get("area"),
+                    criticality="major",
+                    rated_capacity=mapped.get("rated_capacity"),
+                    power_rating=mapped.get("power_rating"),
+                    source="digital-twin",
+                    external_id=remote_id,
+                    sync_version=1,
+                    last_synced_at=datetime.now(timezone.utc),
+                )
+                self.db.add(machine)
+                result.imported_count += 1
+            except Exception as e:
+                result.errors.append(f"설비 {remote_id}: {str(e)}")
+
+        if result.imported_count > 0:
+            await self.db.commit()
+
+        return result
+
+    async def pull_from_remote(self) -> PullResult:
+        result = PullResult()
+        remote_list = await self.fetch_remote_equipment()
+        if not remote_list:
+            return result
+
+        remote_by_id = {str(eq.get("id", "")): eq for eq in remote_list}
+
+        stmt = select(Machine).where(
+            Machine.tenant_id == self.tenant_id,
+            Machine.source == "digital-twin",
+            Machine.external_id.isnot(None),
+        )
+        local_machines = (await self.db.execute(stmt)).scalars().all()
+
+        for machine in local_machines:
+            ext_id = str(machine.external_id)
+            remote = remote_by_id.get(ext_id)
+            if not remote:
+                continue
+
+            remote_updated = remote.get("updatedAt") or remote.get("updated_at")
+            remote_dt = None
+            if remote_updated:
+                try:
+                    remote_dt = datetime.fromisoformat(
+                        str(remote_updated).replace("Z", "+00:00")
+                    )
+                except (ValueError, AttributeError):
+                    pass
+
+            mapped = self._map_remote_to_local(remote)
+            fields_changed = 0
+
+            for field in UPSTREAM_FIELDS:
+                remote_val = mapped.get(field)
+                if remote_val is None:
+                    continue
+
+                if field == "installation_date":
+                    local_val = (
+                        machine.installation_date.isoformat()
+                        if machine.installation_date
+                        else None
+                    )
+                    compare_remote = remote_val
+                else:
+                    local_val = str(getattr(machine, field, "") or "")
+                    compare_remote = str(remote_val or "")
+
+                if local_val == compare_remote:
+                    continue
+
+                local_updated = machine.updated_at
+                if remote_dt and local_updated and remote_dt <= local_updated:
+                    continue
+
+                history = MachineChangeHistory(
+                    tenant_id=self.tenant_id,
+                    machine_id=machine.id,
+                    field_name=field,
+                    old_value=str(local_val) if local_val else None,
+                    new_value=str(remote_val) if remote_val else None,
+                    change_source="sync",
+                    changed_at=datetime.now(timezone.utc),
+                )
+                self.db.add(history)
+
+                if field == "installation_date":
+                    try:
+                        setattr(
+                            machine,
+                            field,
+                            datetime.fromisoformat(remote_val.replace("Z", "+00:00")),
+                        )
+                    except (ValueError, AttributeError):
+                        pass
+                else:
+                    setattr(machine, field, remote_val)
+
+                fields_changed += 1
+
+            if fields_changed > 0:
+                machine.sync_version = (machine.sync_version or 0) + 1
+                machine.last_synced_at = datetime.now(timezone.utc)
+                result.synced_count += 1
+                result.fields_updated += fields_changed
+
+        if result.synced_count > 0:
+            await self.db.commit()
+
+        return result
+
+    async def push_to_remote(self, machine_id: UUID) -> PushResult:
+        if not self.api_url:
+            return PushResult(
+                success=False, error="DIGITAL_TWIN_API_URL이 설정되지 않았습니다."
+            )
+
+        stmt = select(Machine).where(
+            Machine.id == machine_id,
+            Machine.tenant_id == self.tenant_id,
+            Machine.source == "digital-twin",
+        )
+        machine = (await self.db.execute(stmt)).scalar_one_or_none()
+        if not machine or not machine.external_id:
+            return PushResult(success=False, error="동기화 대상 설비가 아닙니다.")
+
+        payload = {}
+        reverse_mapping = {v: k for k, v in FIELD_MAPPING.items()}
+        pushed_fields = []
+
+        for local_field in UPSTREAM_FIELDS | LOCAL_FIELDS:
+            remote_key = reverse_mapping.get(local_field)
+            if not remote_key:
+                continue
+            val = getattr(machine, local_field, None)
+            if val is not None:
+                if hasattr(val, "isoformat"):
+                    payload[remote_key] = val.isoformat()
+                else:
+                    payload[remote_key] = str(val)
+                pushed_fields.append(local_field)
+
+        try:
+            async with self._http_client() as client:
+                resp = await client.put(
+                    f"/api/v1/aas/equipment/{machine.external_id}",
+                    json=payload,
+                )
+                resp.raise_for_status()
+            return PushResult(success=True, fields_pushed=pushed_fields)
+        except Exception as e:
+            logger.error(f"Failed to push to digital-twin: {e}")
+            return PushResult(success=False, error=str(e))
+
+    async def sync(self) -> SyncResult:
+        if not self.api_url:
+            return SyncResult(
+                pull=PullResult(errors=["DIGITAL_TWIN_API_URL이 설정되지 않았습니다."]),
+            )
+
+        pull_result = await self.pull_from_remote()
+
+        push_count = 0
+        push_errors: list[str] = []
+
+        stmt = select(Machine).where(
+            Machine.tenant_id == self.tenant_id,
+            Machine.source == "digital-twin",
+            Machine.external_id.isnot(None),
+        )
+        synced_machines = (await self.db.execute(stmt)).scalars().all()
+
+        for machine in synced_machines:
+            push_result = await self.push_to_remote(machine.id)
+            if push_result.success:
+                push_count += 1
+            elif push_result.error:
+                push_errors.append(f"{machine.name}: {push_result.error}")
+
+        return SyncResult(
+            pull=pull_result,
+            push_count=push_count,
+            push_errors=push_errors,
+        )
+
+    async def record_change(
+        self,
+        machine_id: UUID,
+        field_name: str,
+        old_value: Optional[str],
+        new_value: Optional[str],
+        change_source: str,
+        changed_by: Optional[UUID] = None,
+    ):
+        history = MachineChangeHistory(
+            tenant_id=self.tenant_id,
+            machine_id=machine_id,
+            field_name=field_name,
+            old_value=old_value,
+            new_value=new_value,
+            change_source=change_source,
+            changed_by=changed_by,
+            changed_at=datetime.now(timezone.utc),
+        )
+        self.db.add(history)
diff --git a/start-dev.sh b/start-dev.sh
new file mode 100755
index 0000000..8dba42b
--- /dev/null
+++ b/start-dev.sh
@@ -0,0 +1,334 @@
+#!/bin/bash
+
+# FactoryOps v2 개발 환경 시작 스크립트 (Podman)
+
+# 색상 정의
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+BLUE='\033[0;34m'
+CYAN='\033[0;36m'
+NC='\033[0m'
+
+# 스크립트 위치 기준으로 프로젝트 루트 이동
+cd "$(dirname "$0")" || exit 1
+
+COMPOSE_FILE="docker-compose.dev.yml"
+PROJECT_NAME="factoryops-dev"
+
+# 도움말
+show_help() {
+    echo "사용법: $0 [OPTIONS]"
+    echo ""
+    echo "옵션:"
+    echo "  -l, --logs       로그 표시 모드 (기본: 백그라운드)"
+    echo "  -c, --clean      완전 초기화 (볼륨 포함 모든 리소스 삭제)"
+    echo "  -r, --rebuild    이미지 강제 재빌드"
+    echo "  -h, --help       도움말 표시"
+    echo ""
+    echo "실행 예시:"
+    echo "  $0               # 빠른 시작 (기존 이미지 재사용)"
+    echo "  $0 -l            # 로그 표시 모드"
+    echo "  $0 -r            # 이미지 재빌드"
+    echo "  $0 -c            # 완전 초기화 후 시작"
+    echo "  $0 -c -r         # 완전 초기화 + 이미지 재빌드"
+    echo ""
+    echo "서비스:"
+    echo "  PostgreSQL   → localhost:5432"
+    echo "  FastAPI      → localhost:8000  (uvicorn --reload)"
+    echo "  Next.js      → localhost:3100  (npm run dev)"
+}
+
+# Podman 설치 확인
+check_podman() {
+    if ! command -v podman &> /dev/null; then
+        echo -e "${RED}Podman이 설치되어 있지 않습니다.${NC}"
+        echo "설치: brew install podman"
+        exit 1
+    fi
+}
+
+# Podman Machine 상태 확인 및 복구 (macOS)
+check_and_fix_podman() {
+    echo -e "${BLUE}Podman 상태 확인 중...${NC}"
+
+    # Linux에서는 Podman Machine 불필요
+    if [[ "$(uname -s)" != "Darwin" ]]; then
+        if podman ps >/dev/null 2>&1; then
+            echo -e "${GREEN}  Podman 정상 작동${NC}"
+            return 0
+        else
+            echo -e "${RED}  Podman 연결 실패${NC}"
+            exit 1
+        fi
+    fi
+
+    # macOS: Podman Machine 확인
+    if ! podman machine list 2>/dev/null | grep -q "Running"; then
+        echo -e "${YELLOW}  Podman Machine이 실행되지 않았습니다. 시작 중...${NC}"
+        podman machine start 2>/dev/null || {
+            echo -e "${YELLOW}  Podman Machine 초기화 중...${NC}"
+            podman machine init --cpus 4 --memory 8192
+            podman machine start
+        }
+        sleep 3
+    fi
+
+    # 연결 테스트 (최대 3회)
+    local max_attempts=3
+    local attempt=1
+
+    while [ $attempt -le $max_attempts ]; do
+        if podman ps >/dev/null 2>&1; then
+            echo -e "${GREEN}  Podman 정상 작동${NC}"
+            return 0
+        fi
+
+        echo -e "${YELLOW}  연결 실패. 복구 시도 ($attempt/$max_attempts)...${NC}"
+
+        pkill -9 -f "gvproxy" 2>/dev/null || true
+        sleep 2
+
+        podman machine stop 2>/dev/null || true
+        sleep 2
+        podman machine start 2>/dev/null || {
+            echo -e "${RED}  Podman Machine 재시작 실패${NC}"
+            podman machine rm -f podman-machine-default 2>/dev/null || true
+            podman machine init --cpus 4 --memory 8192
+            podman machine start
+        }
+
+        sleep 3
+        attempt=$((attempt + 1))
+    done
+
+    echo -e "${RED}Podman 복구 실패. 수동으로 확인해주세요:${NC}"
+    echo "  podman machine stop && podman machine start"
+    exit 1
+}
+
+# factoryops-dev 관련 리소스만 정리 (다른 프로젝트 보존)
+cleanup_project_resources() {
+    echo -e "${BLUE}FactoryOps 개발 리소스 정리 중...${NC}"
+    echo ""
+
+    # 1. 실행 중인 컨테이너 중지
+    echo -e "${BLUE}  [1/5] 컨테이너 중지 및 제거...${NC}"
+    local containers=$(podman ps -aq --filter "name=factoryops-dev" 2>/dev/null || true)
+    if [ -n "$containers" ]; then
+        echo "$containers" | xargs -r podman stop -t 5 2>/dev/null || true
+        echo "$containers" | xargs -r podman rm -f 2>/dev/null || true
+        echo -e "${GREEN}       컨테이너 제거 완료${NC}"
+    else
+        echo -e "${GREEN}       제거할 컨테이너 없음${NC}"
+    fi
+
+    # 2. Pod 정리
+    echo -e "${BLUE}  [2/5] Pod 정리...${NC}"
+    local pods=$(podman pod ls --filter "name=factoryops" --format "{{.ID}}" 2>/dev/null || true)
+    if [ -n "$pods" ]; then
+        echo "$pods" | xargs -r podman pod rm -f 2>/dev/null || true
+        echo -e "${GREEN}       Pod 제거 완료${NC}"
+    else
+        echo -e "${GREEN}       제거할 Pod 없음${NC}"
+    fi
+
+    # 3. 네트워크 정리
+    echo -e "${BLUE}  [3/5] 네트워크 정리...${NC}"
+    local networks=$(podman network ls --format "{{.Name}}" 2>/dev/null | grep "factoryops-dev" || true)
+    if [ -n "$networks" ]; then
+        echo "$networks" | xargs -r podman network rm -f 2>/dev/null || true
+        echo -e "${GREEN}       네트워크 제거 완료${NC}"
+    else
+        echo -e "${GREEN}       제거할 네트워크 없음${NC}"
+    fi
+
+    # 4. 볼륨 정리
+    echo -e "${BLUE}  [4/5] 볼륨 정리...${NC}"
+    local volumes=$(podman volume ls --format "{{.Name}}" 2>/dev/null | grep "factoryops" || true)
+    if [ -n "$volumes" ]; then
+        echo "$volumes" | xargs -r podman volume rm -f 2>/dev/null || true
+        echo -e "${GREEN}       볼륨 제거 완료 (DB 데이터 포함)${NC}"
+    else
+        echo -e "${GREEN}       제거할 볼륨 없음${NC}"
+    fi
+
+    # 5. 이미지 정리
+    echo -e "${BLUE}  [5/5] 이미지 정리...${NC}"
+    local images=$(podman images --format "{{.ID}} {{.Repository}}" 2>/dev/null | grep "factoryops" | awk '{print $1}' || true)
+    if [ -n "$images" ]; then
+        echo "$images" | xargs -r podman rmi -f 2>/dev/null || true
+        echo -e "${GREEN}       이미지 제거 완료${NC}"
+    else
+        echo -e "${GREEN}       제거할 이미지 없음${NC}"
+    fi
+
+    echo ""
+    echo -e "${GREEN}  초기화 완료 (다른 프로젝트 리소스 보존됨)${NC}"
+    echo ""
+}
+
+# 포트 충돌 확인 및 해결
+check_and_free_ports() {
+    echo -e "${BLUE}포트 사용 확인 중...${NC}"
+
+    local ports=(8000 3100)
+    local port_names=("FastAPI" "Next.js")
+    local ports_freed=false
+
+    for i in "${!ports[@]}"; do
+        local port=${ports[$i]}
+        local name=${port_names[$i]}
+        if lsof -ti:$port >/dev/null 2>&1; then
+            echo -e "${YELLOW}  포트 $port ($name) 사용 중 → 프로세스 종료${NC}"
+            lsof -ti:$port | xargs kill -9 2>/dev/null || true
+            ports_freed=true
+            sleep 1
+        fi
+    done
+
+    if [ "$ports_freed" = true ]; then
+        echo -e "${GREEN}  포트 정리 완료${NC}"
+        sleep 2
+    else
+        echo -e "${GREEN}  모든 포트 사용 가능${NC}"
+    fi
+}
+
+# 서비스 헬스체크 대기
+wait_for_services() {
+    echo ""
+    echo -e "${BLUE}서비스 준비 대기 중...${NC}"
+
+    # API 대기
+    waited=0
+    echo -ne "${BLUE}  FastAPI    "
+    while [ $waited -lt $max_wait ]; do
+        if curl -sf http://localhost:8000/api/health >/dev/null 2>&1; then
+            echo -e " ${GREEN}ready${NC}"
+            break
+        fi
+        echo -n "."
+        sleep 2
+        waited=$((waited + 2))
+    done
+    if [ $waited -ge $max_wait ]; then
+        echo -e " ${YELLOW}timeout (로그를 확인하세요)${NC}"
+    fi
+
+    # Dashboard 대기 (npm install이 오래 걸릴 수 있음)
+    waited=0
+    max_wait=120
+    echo -ne "${BLUE}  Next.js    "
+    while [ $waited -lt $max_wait ]; do
+        if curl -sf http://localhost:3100 >/dev/null 2>&1; then
+            echo -e " ${GREEN}ready${NC}"
+            break
+        fi
+        echo -n "."
+        sleep 3
+        waited=$((waited + 3))
+    done
+    if [ $waited -ge $max_wait ]; then
+        echo -e " ${YELLOW}아직 준비 중 (npm install 진행 중일 수 있음)${NC}"
+    fi
+}
+
+# ─── 인자 파싱 ───
+SHOW_LOGS=false
+FULL_CLEAN=false
+FORCE_REBUILD=false
+
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        -l|--logs)    SHOW_LOGS=true;    shift ;;
+        -c|--clean)   FULL_CLEAN=true;   shift ;;
+        -r|--rebuild) FORCE_REBUILD=true; shift ;;
+        -h|--help)    show_help; exit 0 ;;
+        *) echo "알 수 없는 옵션: $1"; show_help; exit 1 ;;
+    esac
+done
+
+# ─── 실행 시작 ───
+echo -e "${CYAN}"
+echo "================================================="
+echo "  FactoryOps v2 개발 환경 시작"
+echo "================================================="
+echo -e "${NC}"
+
+check_podman
+check_and_fix_podman
+
+# 완전 초기화 또는 빠른 시작
+if [ "$FULL_CLEAN" = true ]; then
+    echo -e "${YELLOW}완전 초기화 모드 (-c)${NC}"
+    echo -e "${YELLOW}  factoryops 관련 리소스만 삭제됩니다 (볼륨/DB 포함)${NC}"
+    echo ""
+    cleanup_project_resources
+else
+    echo -e "${GREEN}빠른 시작 모드 (기존 리소스 재사용)${NC}"
+    echo -e "${BLUE}  완전 초기화가 필요하면: $0 -c${NC}"
+    echo ""
+
+    # 실행 중인 컨테이너만 중지
+    running=$(podman ps -q --filter "name=factoryops-dev" 2>/dev/null || true)
+    if [ -n "$running" ]; then
+        echo -e "${YELLOW}  기존 컨테이너 중지 중...${NC}"
+        echo "$running" | xargs -r podman stop -t 5 2>/dev/null || true
+        echo -e "${GREEN}  기존 컨테이너 중지 완료${NC}"
+    fi
+    echo ""
+fi
+
+check_and_free_ports
+
+# 빌드 & 실행 옵션
+BUILD_OPTIONS=""
+RUN_OPTIONS=""
+
+if [ "$FORCE_REBUILD" = true ]; then
+    BUILD_OPTIONS="--build --no-cache"
+    echo -e "${BLUE}이미지 재빌드 모드 활성화 (-r)${NC}"
+else
+    echo -e "${GREEN}기존 이미지 재사용 (재빌드: $0 -r)${NC}"
+fi
+
+if [ "$SHOW_LOGS" = false ]; then
+    RUN_OPTIONS="-d"
+fi
+
+echo ""
+echo -e "${BLUE}서비스 시작 중...${NC}"
+
+# compose 실행
+podman compose -f "$COMPOSE_FILE" up $RUN_OPTIONS $BUILD_OPTIONS 2>&1 | \
+    grep -v "WARNING" || true
+
+if [ "$SHOW_LOGS" = false ]; then
+    wait_for_services
+fi
+
+echo ""
+echo -e "${CYAN}"
+echo "================================================="
+echo "  FactoryOps v2 개발 환경 시작 완료"
+echo "================================================="
+echo -e "${NC}"
+echo "  서비스 접속:"
+echo "    Frontend   http://localhost:3100"
+echo "    Backend    http://localhost:8000"
+echo "    API Docs   http://localhost:8000/docs"
+echo "    Database   211.115.91.141:8200 (원격 DB)"
+echo ""
+
+if [ "$SHOW_LOGS" = false ]; then
+    echo "  로그 확인:"
+    echo "    podman compose -f $COMPOSE_FILE logs -f"
+    echo "    podman compose -f $COMPOSE_FILE logs -f api"
+    echo "    podman compose -f $COMPOSE_FILE logs -f dashboard"
+    echo ""
+fi
+
+echo "  중지:"
+echo "    ./stop-dev.sh"
+echo ""
diff --git a/stop-dev.sh b/stop-dev.sh
new file mode 100755
index 0000000..626a811
--- /dev/null
+++ b/stop-dev.sh
@@ -0,0 +1,71 @@
+#!/bin/bash
+
+# FactoryOps v2 개발 환경 중지 스크립트 (Podman)
+
+# 색상 정의
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+BLUE='\033[0;34m'
+CYAN='\033[0;36m'
+NC='\033[0m'
+
+# 스크립트 위치 기준으로 프로젝트 루트 이동
+cd "$(dirname "$0")" || exit 1
+
+COMPOSE_FILE="docker-compose.dev.yml"
+
+echo -e "${CYAN}"
+echo "================================================="
+echo "  FactoryOps v2 개발 환경 중지"
+echo "================================================="
+echo -e "${NC}"
+
+# Podman 설치 확인
+if ! command -v podman &> /dev/null; then
+    echo -e "${RED}Podman이 설치되어 있지 않습니다.${NC}"
+    exit 1
+fi
+
+# 실행 중인 컨테이너 확인
+running=$(podman ps --format "{{.Names}}" 2>/dev/null | grep "factoryops-dev" || true)
+
+if [ -z "$running" ]; then
+    echo -e "${YELLOW}실행 중인 FactoryOps 컨테이너가 없습니다.${NC}"
+    exit 0
+fi
+
+echo -e "${YELLOW}중지할 컨테이너:${NC}"
+echo "$running" | while read -r name; do
+    echo "  - $name"
+done
+echo ""
+
+# 서비스 중지
+echo -e "${BLUE}서비스 중지 중...${NC}"
+podman compose -f "$COMPOSE_FILE" down 2>/dev/null || true
+
+echo ""
+echo -e "${CYAN}"
+echo "================================================="
+echo "  FactoryOps v2 개발 환경 중지 완료"
+echo "================================================="
+echo -e "${NC}"
+
+# 남아있는 컨테이너 확인
+remaining=$(podman ps -a --format "{{.Names}}" 2>/dev/null | grep "factoryops-dev" || true)
+
+if [ -n "$remaining" ]; then
+    echo -e "${YELLOW}아직 남아있는 컨테이너:${NC}"
+    echo "$remaining"
+    echo ""
+    echo -e "${YELLOW}완전히 제거하려면:${NC}"
+    echo "  podman compose -f $COMPOSE_FILE down --volumes"
+else
+    echo -e "${GREEN}모든 컨테이너가 정상 중지되었습니다.${NC}"
+fi
+
+echo ""
+echo "  다시 시작하려면:  ./start-dev.sh"
+echo "  완전 초기화:     ./start-dev.sh -c"
+echo ""
diff --git a/tests/test_equipment_sync.py b/tests/test_equipment_sync.py
new file mode 100644
index 0000000..7d45a55
--- /dev/null
+++ b/tests/test_equipment_sync.py
@@ -0,0 +1,706 @@
+import os
+import json
+from datetime import datetime, timezone
+from unittest.mock import AsyncMock, patch, MagicMock
+from uuid import uuid4
+
+import pytest
+from httpx import AsyncClient
+from tests.conftest import get_auth_headers
+
+
+MOCK_REMOTE_EQUIPMENT = [
+    {
+        "id": "dt-001",
+        "equipmentName": "Press Machine 1",
+        "equipmentId": "PM-001",
+        "model": "XM-200",
+        "manufacturer": "TestCorp",
+        "installationDate": "2024-01-15T00:00:00Z",
+        "location": "Bay 1",
+        "capacity": "200t",
+        "powerConsumption": "50kW",
+        "updatedAt": "2025-01-01T00:00:00Z",
+    },
+    {
+        "id": "dt-002",
+        "equipmentName": "Press Machine 2",
+        "equipmentId": "PM-002",
+        "model": "XM-300",
+        "manufacturer": "TestCorp",
+        "installationDate": "2024-06-01T00:00:00Z",
+        "location": "Bay 2",
+        "capacity": "300t",
+        "powerConsumption": "75kW",
+        "updatedAt": "2025-01-01T00:00:00Z",
+    },
+]
+
+
+@pytest.mark.asyncio
+async def test_import_preview(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            resp = await client.get(
+                "/api/test-co/machines/import/preview", headers=headers
+            )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert "equipment" in data
+    assert data["total"] == 2
+    assert len(data["equipment"]) == 2
+    assert data["equipment"][0]["id"] == "dt-001"
+    assert data["equipment"][0]["name"] == "Press Machine 1"
+    assert data["equipment"][0]["equipment_code"] == "PM-001"
+    assert data["equipment"][0]["already_imported"] is False
+
+
+@pytest.mark.asyncio
+async def test_import_preview_marks_existing_as_imported(
+    client: AsyncClient, seeded_db
+):
+    headers = await get_auth_headers(client)
+
+    create_resp = await client.post(
+        "/api/test-co/machines",
+        json={"name": "Press Machine 1", "equipment_code": "PM-001"},
+        headers=headers,
+    )
+    machine_id = create_resp.json()["id"]
+
+    from sqlalchemy import select
+    from src.database.models import Machine
+
+    stmt = select(Machine).where(Machine.id == machine_id)
+    machine = (await seeded_db.execute(stmt)).scalar_one()
+    machine.external_id = "dt-001"
+    machine.source = "digital-twin"
+    await seeded_db.commit()
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            resp = await client.get(
+                "/api/test-co/machines/import/preview", headers=headers
+            )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["equipment"][0]["already_imported"] is True
+    assert data["equipment"][1]["already_imported"] is False
+
+
+@pytest.mark.asyncio
+async def test_import_equipment(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            resp = await client.post(
+                "/api/test-co/machines/import",
+                json={},
+                headers=headers,
+            )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["imported_count"] == 2
+    assert data["skipped_count"] == 0
+    assert len(data["errors"]) == 0
+
+    list_resp = await client.get("/api/test-co/machines", headers=headers)
+    machines = list_resp.json()["machines"]
+    assert len(machines) == 2
+    assert machines[0]["source"] == "digital-twin"
+    assert machines[0]["external_id"] == "dt-001"
+
+
+@pytest.mark.asyncio
+async def test_import_equipment_with_specific_ids(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            resp = await client.post(
+                "/api/test-co/machines/import",
+                json={"external_ids": ["dt-001"]},
+                headers=headers,
+            )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["imported_count"] == 1
+    assert data["skipped_count"] == 0
+
+    list_resp = await client.get("/api/test-co/machines", headers=headers)
+    machines = list_resp.json()["machines"]
+    assert len(machines) == 1
+    assert machines[0]["name"] == "Press Machine 1"
+
+
+@pytest.mark.asyncio
+async def test_import_skips_duplicates(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            resp1 = await client.post(
+                "/api/test-co/machines/import",
+                json={},
+                headers=headers,
+            )
+
+    assert resp1.status_code == 200
+    assert resp1.json()["imported_count"] == 2
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            resp2 = await client.post(
+                "/api/test-co/machines/import",
+                json={},
+                headers=headers,
+            )
+
+    assert resp2.status_code == 200
+    assert resp2.json()["imported_count"] == 0
+    assert resp2.json()["skipped_count"] == 2
+
+
+@pytest.mark.asyncio
+async def test_sync_endpoint(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            await client.post(
+                "/api/test-co/machines/import",
+                json={},
+                headers=headers,
+            )
+
+    updated_equipment = [
+        {
+            "id": "dt-001",
+            "equipmentName": "Press Machine 1 Updated",
+            "equipmentId": "PM-001",
+            "model": "XM-200-V2",
+            "manufacturer": "TestCorp",
+            "installationDate": "2024-01-15T00:00:00Z",
+            "location": "Bay 1",
+            "capacity": "200t",
+            "powerConsumption": "50kW",
+            "updatedAt": "2025-02-01T00:00:00Z",
+        },
+    ]
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = updated_equipment
+
+        with patch(
+            "src.services.equipment_sync.EquipmentSyncService.push_to_remote",
+            new_callable=AsyncMock,
+        ) as mock_push:
+            from src.services.equipment_sync import PushResult
+
+            mock_push.return_value = PushResult(success=True, fields_pushed=["name"])
+
+            with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+                resp = await client.post(
+                    "/api/test-co/machines/sync",
+                    headers=headers,
+                )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert "pull" in data
+    assert "push_count" in data
+    assert data["pull"]["synced_count"] == 1
+    assert data["pull"]["fields_updated"] == 1
+
+
+@pytest.mark.asyncio
+async def test_machine_history_endpoint(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    create_resp = await client.post(
+        "/api/test-co/machines",
+        json={"name": "Test Machine", "equipment_code": "TM-001"},
+        headers=headers,
+    )
+    machine_id = create_resp.json()["id"]
+
+    await client.put(
+        f"/api/test-co/machines/{machine_id}",
+        json={"name": "Test Machine Updated"},
+        headers=headers,
+    )
+
+    resp = await client.get(
+        f"/api/test-co/machines/{machine_id}/history",
+        headers=headers,
+    )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert "history" in data
+    assert "total" in data
+    assert data["total"] >= 1
+    assert any(h["field_name"] == "name" for h in data["history"])
+
+
+@pytest.mark.asyncio
+async def test_machine_history_pagination(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    create_resp = await client.post(
+        "/api/test-co/machines",
+        json={"name": "Test Machine", "equipment_code": "TM-001"},
+        headers=headers,
+    )
+    machine_id = create_resp.json()["id"]
+
+    for i in range(5):
+        await client.put(
+            f"/api/test-co/machines/{machine_id}",
+            json={"description": f"Update {i}"},
+            headers=headers,
+        )
+
+    resp = await client.get(
+        f"/api/test-co/machines/{machine_id}/history?limit=2&offset=0",
+        headers=headers,
+    )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert len(data["history"]) == 2
+    assert data["total"] >= 5
+
+
+@pytest.mark.asyncio
+async def test_update_machine_records_history(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    create_resp = await client.post(
+        "/api/test-co/machines",
+        json={"name": "Original Name", "equipment_code": "OM-001"},
+        headers=headers,
+    )
+    machine_id = create_resp.json()["id"]
+
+    update_resp = await client.put(
+        f"/api/test-co/machines/{machine_id}",
+        json={
+            "name": "Updated Name",
+            "equipment_code": "UM-001",
+            "model": "Model-X",
+        },
+        headers=headers,
+    )
+
+    assert update_resp.status_code == 200
+
+    history_resp = await client.get(
+        f"/api/test-co/machines/{machine_id}/history",
+        headers=headers,
+    )
+
+    history = history_resp.json()["history"]
+    assert len(history) >= 3
+
+    name_change = next((h for h in history if h["field_name"] == "name"), None)
+    assert name_change is not None
+    assert name_change["old_value"] == "Original Name"
+    assert name_change["new_value"] == "Updated Name"
+    assert name_change["change_source"] == "local"
+
+    code_change = next(
+        (h for h in history if h["field_name"] == "equipment_code"), None
+    )
+    assert code_change is not None
+    assert code_change["old_value"] == "OM-001"
+    assert code_change["new_value"] == "UM-001"
+
+
+@pytest.mark.asyncio
+async def test_sync_without_config_returns_503(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch.dict(os.environ, {}, clear=False):
+        if "DIGITAL_TWIN_API_URL" in os.environ:
+            del os.environ["DIGITAL_TWIN_API_URL"]
+
+        resp = await client.post(
+            "/api/test-co/machines/sync",
+            headers=headers,
+        )
+
+    assert resp.status_code == 503
+    assert "DIGITAL_TWIN_API_URL" in resp.json()["detail"]
+
+
+@pytest.mark.asyncio
+async def test_import_without_config_returns_503(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch.dict(os.environ, {}, clear=False):
+        if "DIGITAL_TWIN_API_URL" in os.environ:
+            del os.environ["DIGITAL_TWIN_API_URL"]
+
+        resp = await client.post(
+            "/api/test-co/machines/import",
+            json={},
+            headers=headers,
+        )
+
+    assert resp.status_code == 503
+    assert "DIGITAL_TWIN_API_URL" in resp.json()["detail"]
+
+
+@pytest.mark.asyncio
+async def test_import_preview_without_config_returns_503(
+    client: AsyncClient, seeded_db
+):
+    headers = await get_auth_headers(client)
+
+    with patch.dict(os.environ, {}, clear=False):
+        if "DIGITAL_TWIN_API_URL" in os.environ:
+            del os.environ["DIGITAL_TWIN_API_URL"]
+
+        resp = await client.get(
+            "/api/test-co/machines/import/preview",
+            headers=headers,
+        )
+
+    assert resp.status_code == 503
+    assert "DIGITAL_TWIN_API_URL" in resp.json()["detail"]
+
+
+@pytest.mark.asyncio
+async def test_tenant_isolation_sync(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            resp_test = await client.post(
+                "/api/test-co/machines/import",
+                json={},
+                headers=headers,
+            )
+
+    assert resp_test.status_code == 200
+    assert resp_test.json()["imported_count"] == 2
+
+    list_test = await client.get("/api/test-co/machines", headers=headers)
+    list_other = await client.get("/api/other-co/machines", headers=headers)
+
+    assert len(list_test.json()["machines"]) == 2
+    assert len(list_other.json()["machines"]) == 0
+
+
+@pytest.mark.asyncio
+async def test_sync_lww_logic_remote_wins(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            await client.post(
+                "/api/test-co/machines/import",
+                json={"external_ids": ["dt-001"]},
+                headers=headers,
+            )
+
+    machines_resp = await client.get("/api/test-co/machines", headers=headers)
+    machine_id = machines_resp.json()["machines"][0]["id"]
+
+    await client.put(
+        f"/api/test-co/machines/{machine_id}",
+        json={"name": "Local Update"},
+        headers=headers,
+    )
+
+    remote_updated = [
+        {
+            "id": "dt-001",
+            "equipmentName": "Remote Update",
+            "equipmentId": "PM-001",
+            "model": "XM-200",
+            "manufacturer": "TestCorp",
+            "installationDate": "2024-01-15T00:00:00Z",
+            "location": "Bay 1",
+            "capacity": "200t",
+            "powerConsumption": "50kW",
+            "updatedAt": "2025-02-11T12:00:00Z",
+        },
+    ]
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = remote_updated
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            sync_resp = await client.post(
+                "/api/test-co/machines/sync",
+                headers=headers,
+            )
+
+    assert sync_resp.status_code == 200
+    assert sync_resp.json()["pull"]["synced_count"] == 1
+
+    updated_machine = await client.get(
+        f"/api/test-co/machines/{machine_id}",
+        headers=headers,
+    )
+    assert updated_machine.json()["name"] == "Remote Update"
+
+
+@pytest.mark.asyncio
+async def test_sync_lww_logic_local_wins(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            await client.post(
+                "/api/test-co/machines/import",
+                json={"external_ids": ["dt-001"]},
+                headers=headers,
+            )
+
+    machines_resp = await client.get("/api/test-co/machines", headers=headers)
+    machine_id = machines_resp.json()["machines"][0]["id"]
+
+    await client.put(
+        f"/api/test-co/machines/{machine_id}",
+        json={"name": "Local Update"},
+        headers=headers,
+    )
+
+    remote_old = [
+        {
+            "id": "dt-001",
+            "equipmentName": "Remote Old",
+            "equipmentId": "PM-001",
+            "model": "XM-200",
+            "manufacturer": "TestCorp",
+            "installationDate": "2024-01-15T00:00:00Z",
+            "location": "Bay 1",
+            "capacity": "200t",
+            "powerConsumption": "50kW",
+            "updatedAt": "2025-01-01T00:00:00Z",
+        },
+    ]
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = remote_old
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            sync_resp = await client.post(
+                "/api/test-co/machines/sync",
+                headers=headers,
+            )
+
+    assert sync_resp.status_code == 200
+    assert sync_resp.json()["pull"]["synced_count"] == 0
+
+    unchanged_machine = await client.get(
+        f"/api/test-co/machines/{machine_id}",
+        headers=headers,
+    )
+    assert unchanged_machine.json()["name"] == "Local Update"
+
+
+@pytest.mark.asyncio
+async def test_unauthenticated_import_preview(client: AsyncClient, seeded_db):
+    resp = await client.get("/api/test-co/machines/import/preview")
+    assert resp.status_code == 401
+
+
+@pytest.mark.asyncio
+async def test_unauthenticated_import(client: AsyncClient, seeded_db):
+    resp = await client.post("/api/test-co/machines/import", json={})
+    assert resp.status_code == 401
+
+
+@pytest.mark.asyncio
+async def test_unauthenticated_sync(client: AsyncClient, seeded_db):
+    resp = await client.post("/api/test-co/machines/sync")
+    assert resp.status_code == 401
+
+
+@pytest.mark.asyncio
+async def test_tenant_access_denied_import_preview(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client, email="admin@test-co.com")
+
+    resp = await client.get("/api/other-co/machines/import/preview", headers=headers)
+    assert resp.status_code == 403
+
+
+@pytest.mark.asyncio
+async def test_tenant_access_denied_import(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client, email="admin@test-co.com")
+
+    resp = await client.post(
+        "/api/other-co/machines/import",
+        json={},
+        headers=headers,
+    )
+    assert resp.status_code == 403
+
+
+@pytest.mark.asyncio
+async def test_tenant_access_denied_sync(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client, email="admin@test-co.com")
+
+    resp = await client.post("/api/other-co/machines/sync", headers=headers)
+    assert resp.status_code == 403
+
+
+@pytest.mark.asyncio
+async def test_history_endpoint_empty_machine(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    create_resp = await client.post(
+        "/api/test-co/machines",
+        json={"name": "No Changes Machine"},
+        headers=headers,
+    )
+    machine_id = create_resp.json()["id"]
+
+    resp = await client.get(
+        f"/api/test-co/machines/{machine_id}/history",
+        headers=headers,
+    )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["total"] == 0
+    assert len(data["history"]) == 0
+
+
+@pytest.mark.asyncio
+async def test_history_endpoint_nonexistent_machine(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    fake_id = str(uuid4())
+    resp = await client.get(
+        f"/api/test-co/machines/{fake_id}/history",
+        headers=headers,
+    )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["total"] == 0
+    assert len(data["history"]) == 0
+
+
+@pytest.mark.asyncio
+async def test_sync_version_increments(client: AsyncClient, seeded_db):
+    headers = await get_auth_headers(client)
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = MOCK_REMOTE_EQUIPMENT
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            await client.post(
+                "/api/test-co/machines/import",
+                json={"external_ids": ["dt-001"]},
+                headers=headers,
+            )
+
+    machines_resp = await client.get("/api/test-co/machines", headers=headers)
+    machine = machines_resp.json()["machines"][0]
+    assert machine["sync_version"] == 1
+
+    updated_equipment = [
+        {
+            "id": "dt-001",
+            "equipmentName": "Press Machine 1 Updated",
+            "equipmentId": "PM-001",
+            "model": "XM-200-V2",
+            "manufacturer": "TestCorp",
+            "installationDate": "2024-01-15T00:00:00Z",
+            "location": "Bay 1",
+            "capacity": "200t",
+            "powerConsumption": "50kW",
+            "updatedAt": "2025-02-11T12:00:00Z",
+        },
+    ]
+
+    with patch(
+        "src.services.equipment_sync.EquipmentSyncService.fetch_remote_equipment",
+        new_callable=AsyncMock,
+    ) as mock_fetch:
+        mock_fetch.return_value = updated_equipment
+
+        with patch.dict(os.environ, {"DIGITAL_TWIN_API_URL": "http://mock-api"}):
+            await client.post(
+                "/api/test-co/machines/sync",
+                headers=headers,
+            )
+
+    updated_resp = await client.get("/api/test-co/machines", headers=headers)
+    updated_machine = updated_resp.json()["machines"][0]
+    assert updated_machine["sync_version"] == 2