diff --git a/data/page_status.json b/data/page_status.json
index 5fdd111..0aa8e93 100644
--- a/data/page_status.json
+++ b/data/page_status.json
@@ -99,6 +99,13 @@
       "drawer_id": "drawer",
       "order": 3
     },
+    {
+      "route": "/material-trace",
+      "name": "原物料追溯查詢",
+      "status": "released",
+      "drawer_id": "drawer",
+      "order": 4
+    },
     {
       "route": "/admin/pages",
       "name": "頁面管理",
diff --git a/docs/migration/full-modernization-architecture-blueprint/route_contracts.json b/docs/migration/full-modernization-architecture-blueprint/route_contracts.json
index 55821ec..5585c9c 100644
--- a/docs/migration/full-modernization-architecture-blueprint/route_contracts.json
+++ b/docs/migration/full-modernization-architecture-blueprint/route_contracts.json
@@ -191,6 +191,18 @@
       "canonical_shell_path": "/portal-shell/mid-section-defect",
       "rollback_strategy": "fallback_to_legacy_route",
       "compatibility_policy": "redirect_to_shell_when_spa_enabled"
+    },
+    {
+      "route": "/material-trace",
+      "route_id": "material-trace",
+      "title": "Material Trace",
+      "scope": "in-scope",
+      "render_mode": "native",
+      "owner": "frontend-mes-reporting",
+      "visibility_policy": "released_or_admin",
+      "canonical_shell_path": "/portal-shell/material-trace",
+      "rollback_strategy": "fallback_to_legacy_route",
+      "compatibility_policy": "redirect_to_shell_when_spa_enabled"
     }
   ]
 }
diff --git a/frontend/src/material-trace/App.vue b/frontend/src/material-trace/App.vue
new file mode 100644
index 0000000..186da6b
--- /dev/null
+++ b/frontend/src/material-trace/App.vue
@@ -0,0 +1,438 @@
+<script setup>
+import { computed, onMounted, ref } from 'vue';
+
+import { apiGet, apiPost } from '../core/api.js';
+import { parseMultiLineInput } from '../core/reject-history-filters.js';
+
+const API_TIMEOUT = 60000;
+const DEFAULT_PER_PAGE = 50;
+const FORWARD_INPUT_LIMIT = 200;
+const REVERSE_INPUT_LIMIT = 50;
+
+// ---- Query mode state ----
+const queryMode = ref('forward'); // 'forward' | 'reverse'
+const forwardInputType = ref('lot'); // 'lot' | 'workorder'
+const inputText = ref('');
+
+// ---- Filter state ----
+const workcenterGroupOptions = ref([]);
+const selectedWorkcenterGroups = ref([]);
+const workcenterDropdownOpen = ref(false);
+const workcenterSearch = ref('');
+
+// ---- Result state ----
+const rows = ref([]);
+const pagination = ref({ page: 1, per_page: DEFAULT_PER_PAGE, total: 0, total_pages: 0 });
+const loading = ref(false);
+const errorMessage = ref('');
+const warningMessage = ref('');
+const unresolvedWarning = ref('');
+
+// ---- Computed ----
+const parsedValues = computed(() => parseMultiLineInput(inputText.value));
+const inputCount = computed(() => parsedValues.value.length);
+const currentInputLimit = computed(() =>
+  queryMode.value === 'forward' ? FORWARD_INPUT_LIMIT : REVERSE_INPUT_LIMIT,
+);
+const isOverLimit = computed(() => inputCount.value > currentInputLimit.value);
+const hasResults = computed(() => rows.value.length > 0);
+const canQuery = computed(() => inputCount.value > 0 && !isOverLimit.value && !loading.value);
+const canExport = computed(() => hasResults.value && !loading.value);
+
+const queryModeForApi = computed(() => {
+  if (queryMode.value === 'reverse') return 'material_lot';
+  return forwardInputType.value; // 'lot' or 'workorder'
+});
+
+const filteredWorkcenterOptions = computed(() => {
+  const q = workcenterSearch.value.toLowerCase().trim();
+  if (!q) return workcenterGroupOptions.value;
+  return workcenterGroupOptions.value.filter((g) => g.toLowerCase().includes(q));
+});
+
+const workcenterTriggerText = computed(() => {
+  if (selectedWorkcenterGroups.value.length === 0) return '全部站點';
+  if (selectedWorkcenterGroups.value.length === 1) return selectedWorkcenterGroups.value[0];
+  return `已選 ${selectedWorkcenterGroups.value.length} 個站群組`;
+});
+
+// ---- Table columns ----
+const TABLE_COLUMNS = [
+  { key: 'CONTAINERNAME', label: 'LOT ID' },
+  { key: 'PJ_WORKORDER', label: '工單' },
+  { key: 'WORKCENTER_GROUP', label: '站群組' },
+  { key: 'WORKCENTERNAME', label: '站點' },
+  { key: 'MATERIALPARTNAME', label: '料號' },
+  { key: 'MATERIALLOTNAME', label: '物料批號' },
+  { key: 'VENDORLOTNUMBER', label: '供應商批號' },
+  { key: 'QTYREQUIRED', label: '應領量' },
+  { key: 'QTYCONSUMED', label: '實際消耗' },
+  { key: 'EQUIPMENTNAME', label: '機台' },
+  { key: 'TXNDATE', label: '交易日期' },
+  { key: 'PRIMARY_CATEGORY', label: '主分類' },
+  { key: 'SECONDARY_CATEGORY', label: '副分類' },
+];
+
+// ---- Mode switching ----
+function switchQueryMode(mode) {
+  if (queryMode.value === mode) return;
+  queryMode.value = mode;
+  clearAll();
+}
+
+function switchForwardInputType(type) {
+  if (forwardInputType.value === type) return;
+  forwardInputType.value = type;
+  inputText.value = '';
+  clearResults();
+}
+
+function clearAll() {
+  inputText.value = '';
+  clearResults();
+}
+
+function clearResults() {
+  rows.value = [];
+  pagination.value = { page: 1, per_page: DEFAULT_PER_PAGE, total: 0, total_pages: 0 };
+  errorMessage.value = '';
+  warningMessage.value = '';
+  unresolvedWarning.value = '';
+}
+
+// ---- Workcenter multi-select ----
+function toggleWorkcenterGroup(group) {
+  const idx = selectedWorkcenterGroups.value.indexOf(group);
+  if (idx >= 0) {
+    selectedWorkcenterGroups.value.splice(idx, 1);
+  } else {
+    selectedWorkcenterGroups.value.push(group);
+  }
+}
+
+function selectAllWorkcenterGroups() {
+  selectedWorkcenterGroups.value = [...workcenterGroupOptions.value];
+}
+
+function clearWorkcenterGroups() {
+  selectedWorkcenterGroups.value = [];
+}
+
+// ---- API calls ----
+async function loadFilterOptions() {
+  try {
+    const res = await apiGet('/api/material-trace/filter-options', { timeout: API_TIMEOUT });
+    if (res.success && res.data?.workcenter_groups) {
+      workcenterGroupOptions.value = res.data.workcenter_groups;
+    }
+  } catch {
+    // Silently ignore — filter options will be empty
+  }
+}
+
+async function executePrimaryQuery(page = 1) {
+  if (!canQuery.value) return;
+
+  errorMessage.value = '';
+  warningMessage.value = '';
+  unresolvedWarning.value = '';
+  loading.value = true;
+
+  const body = {
+    mode: queryModeForApi.value,
+    values: parsedValues.value,
+    page,
+    per_page: DEFAULT_PER_PAGE,
+  };
+  if (selectedWorkcenterGroups.value.length > 0) {
+    body.workcenter_groups = selectedWorkcenterGroups.value;
+  }
+
+  try {
+    const result = await apiPost('/api/material-trace/query', body, { timeout: API_TIMEOUT });
+
+    if (!result.success) {
+      errorMessage.value = result.error || '查詢失敗';
+      rows.value = [];
+      pagination.value = { page: 1, per_page: DEFAULT_PER_PAGE, total: 0, total_pages: 0 };
+      return;
+    }
+
+    rows.value = result.rows || [];
+    pagination.value = result.pagination || {
+      page: 1,
+      per_page: DEFAULT_PER_PAGE,
+      total: 0,
+      total_pages: 0,
+    };
+
+    // Handle meta warnings
+    if (result.meta?.unresolved?.length > 0) {
+      unresolvedWarning.value = `以下 LOT ID 無法解析：${result.meta.unresolved.join('、')}`;
+    }
+    if (result.meta?.truncated) {
+      warningMessage.value = `查詢結果超過 ${result.meta.max_rows?.toLocaleString() || '10,000'} 筆上限，請縮小查詢範圍`;
+    }
+  } catch (err) {
+    errorMessage.value = err.message || '查詢失敗，請稍後再試';
+    rows.value = [];
+  } finally {
+    loading.value = false;
+  }
+}
+
+function goToPage(page) {
+  executePrimaryQuery(page);
+}
+
+async function exportCsv() {
+  if (!canExport.value) return;
+
+  const body = {
+    mode: queryModeForApi.value,
+    values: parsedValues.value,
+  };
+  if (selectedWorkcenterGroups.value.length > 0) {
+    body.workcenter_groups = selectedWorkcenterGroups.value;
+  }
+
+  try {
+    const response = await fetch('/api/material-trace/export', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(body),
+    });
+
+    if (!response.ok) {
+      const data = await response.json().catch(() => ({}));
+      errorMessage.value = data.error || '匯出失敗';
+      return;
+    }
+
+    const blob = await response.blob();
+    const url = URL.createObjectURL(blob);
+    const a = document.createElement('a');
+    a.href = url;
+    a.download = 'material_trace.csv';
+    a.click();
+    URL.revokeObjectURL(url);
+  } catch (err) {
+    errorMessage.value = err.message || '匯出失敗，請稍後再試';
+  }
+}
+
+// ---- Lifecycle ----
+onMounted(() => {
+  loadFilterOptions();
+});
+
+// Close dropdown on click outside
+function onDocumentClick(e) {
+  if (!e.target.closest('.multi-select')) {
+    workcenterDropdownOpen.value = false;
+  }
+}
+</script>
+
+<template>
+  <div class="dashboard" @click="onDocumentClick">
+    <!-- Header -->
+    <div class="header material-trace-header">
+      <div class="header-left">
+        <h1>原物料追溯查詢</h1>
+      </div>
+    </div>
+
+    <!-- Error / Warning Banners -->
+    <div v-if="errorMessage" class="error-banner">{{ errorMessage }}</div>
+    <div v-if="unresolvedWarning" class="warning-banner">{{ unresolvedWarning }}</div>
+    <div v-if="warningMessage" class="warning-banner">{{ warningMessage }}</div>
+
+    <!-- Query Card -->
+    <div class="card">
+      <div class="card-header">
+        <span class="card-title">查詢條件</span>
+      </div>
+      <div class="card-body">
+        <!-- Mode tabs -->
+        <div class="mode-tab-row" style="margin-bottom: 14px">
+          <button
+            class="mode-tab"
+            :class="{ active: queryMode === 'forward' }"
+            @click="switchQueryMode('forward')"
+          >
+            正向查詢：LOT/工單 → 原物料
+          </button>
+          <button
+            class="mode-tab"
+            :class="{ active: queryMode === 'reverse' }"
+            @click="switchQueryMode('reverse')"
+          >
+            反向查詢：原物料 → LOT
+          </button>
+        </div>
+
+        <div class="filter-panel">
+          <!-- Forward: input type selector -->
+          <div v-if="queryMode === 'forward'" class="filter-group">
+            <label class="filter-label">輸入類型</label>
+            <div class="input-type-row">
+              <select
+                class="filter-input input-type-select"
+                :value="forwardInputType"
+                @change="switchForwardInputType($event.target.value)"
+              >
+                <option value="lot">LOT ID</option>
+                <option value="workorder">工單</option>
+              </select>
+            </div>
+          </div>
+
+          <!-- Workcenter group filter -->
+          <div class="filter-group">
+            <label class="filter-label">站群組篩選</label>
+            <div class="multi-select" @click.stop>
+              <button
+                class="multi-select-trigger"
+                @click="workcenterDropdownOpen = !workcenterDropdownOpen"
+              >
+                <span class="multi-select-text">{{ workcenterTriggerText }}</span>
+                <span class="multi-select-arrow">&#9662;</span>
+              </button>
+              <div v-if="workcenterDropdownOpen" class="multi-select-dropdown">
+                <input
+                  v-model="workcenterSearch"
+                  class="multi-select-search"
+                  placeholder="搜尋站群組..."
+                />
+                <div class="multi-select-options">
+                  <button
+                    v-for="group in filteredWorkcenterOptions"
+                    :key="group"
+                    class="multi-select-option"
+                    @click="toggleWorkcenterGroup(group)"
+                  >
+                    <input
+                      type="checkbox"
+                      :checked="selectedWorkcenterGroups.includes(group)"
+                      tabindex="-1"
+                    />
+                    {{ group }}
+                  </button>
+                  <div v-if="filteredWorkcenterOptions.length === 0" class="multi-select-empty">
+                    無符合的站群組
+                  </div>
+                </div>
+                <div class="multi-select-actions">
+                  <button class="btn-sm" @click="selectAllWorkcenterGroups">全選</button>
+                  <button class="btn-sm" @click="clearWorkcenterGroups">清除</button>
+                </div>
+              </div>
+            </div>
+          </div>
+
+          <!-- Textarea input -->
+          <div class="filter-group filter-group-full">
+            <label class="filter-label">
+              {{
+                queryMode === 'forward'
+                  ? forwardInputType === 'lot'
+                    ? 'LOT ID（每行一筆或逗號分隔，支援萬用字元 * ）'
+                    : '工單號碼（每行一筆或逗號分隔，支援萬用字元 * ）'
+                  : '原物料批號（每行一筆或逗號分隔，支援萬用字元 * ）'
+              }}
+            </label>
+            <textarea
+              v-model="inputText"
+              class="filter-input filter-textarea"
+              rows="5"
+              :placeholder="
+                queryMode === 'forward'
+                  ? forwardInputType === 'lot'
+                    ? 'GA25060001-A01\nGA250605*\n...'
+                    : 'WO-2025-001\nWO-2025*\n...'
+                  : 'WIRE-LOT-20250101-A\nSLD-LOT-2025*\n...'
+              "
+            ></textarea>
+            <div class="input-count" :class="{ 'over-limit': isOverLimit }">
+              已輸入 {{ inputCount }} 筆
+              <template v-if="isOverLimit">
+                （超過上限 {{ currentInputLimit }} 筆）
+              </template>
+            </div>
+          </div>
+
+          <!-- Buttons -->
+          <div class="filter-toolbar">
+            <div class="filter-actions">
+              <button class="btn btn-primary" :disabled="!canQuery" @click="executePrimaryQuery()">
+                <span v-if="loading" class="btn-spinner"></span>
+                查詢
+              </button>
+              <button class="btn btn-secondary" @click="clearAll">清除</button>
+              <button class="btn btn-export" :disabled="!canExport" @click="exportCsv">
+                匯出 CSV
+              </button>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>
+
+    <!-- Result Card -->
+    <div v-if="hasResults || loading" class="card">
+      <div class="card-header">
+        <span class="card-title">
+          查詢結果
+          <template v-if="pagination.total > 0">
+            （共 {{ pagination.total.toLocaleString() }} 筆）
+          </template>
+        </span>
+      </div>
+      <div class="card-body">
+        <!-- Loading overlay -->
+        <div class="detail-table-wrap" :class="{ 'is-loading': loading }">
+          <div v-if="loading" class="table-loading-overlay">
+            <span class="table-spinner"></span>
+          </div>
+          <table class="detail-table">
+            <thead>
+              <tr>
+                <th v-for="col in TABLE_COLUMNS" :key="col.key">{{ col.label }}</th>
+              </tr>
+            </thead>
+            <tbody>
+              <tr v-for="(row, idx) in rows" :key="idx">
+                <td v-for="col in TABLE_COLUMNS" :key="col.key">{{ row[col.key] ?? '' }}</td>
+              </tr>
+            </tbody>
+          </table>
+        </div>
+
+        <!-- Empty message -->
+        <div v-if="!loading && rows.length === 0 && pagination.total === 0" class="empty-message">
+          查無資料
+        </div>
+
+        <!-- Pagination -->
+        <div v-if="pagination.total_pages > 1" class="pagination-bar">
+          <div class="pagination-info">
+            第 {{ pagination.page }} / {{ pagination.total_pages }} 頁，共
+            {{ pagination.total.toLocaleString() }} 筆
+          </div>
+          <div class="pagination-actions">
+            <button :disabled="pagination.page <= 1" @click="goToPage(pagination.page - 1)">
+              上一頁
+            </button>
+            <button
+              :disabled="pagination.page >= pagination.total_pages"
+              @click="goToPage(pagination.page + 1)"
+            >
+              下一頁
+            </button>
+          </div>
+        </div>
+      </div>
+    </div>
+  </div>
+</template>
diff --git a/frontend/src/material-trace/index.html b/frontend/src/material-trace/index.html
new file mode 100644
index 0000000..8074ca2
--- /dev/null
+++ b/frontend/src/material-trace/index.html
@@ -0,0 +1,12 @@
+<!doctype html>
+<html lang="zh-Hant">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>原物料追溯查詢</title>
+  </head>
+  <body>
+    <div id="app"></div>
+    <script type="module" src="./main.js"></script>
+  </body>
+</html>
diff --git a/frontend/src/material-trace/main.js b/frontend/src/material-trace/main.js
new file mode 100644
index 0000000..badc9a1
--- /dev/null
+++ b/frontend/src/material-trace/main.js
@@ -0,0 +1,7 @@
+import { createApp } from 'vue';
+
+import App from './App.vue';
+import '../wip-shared/styles.css';
+import './style.css';
+
+createApp(App).mount('#app');
diff --git a/frontend/src/material-trace/style.css b/frontend/src/material-trace/style.css
new file mode 100644
index 0000000..507b438
--- /dev/null
+++ b/frontend/src/material-trace/style.css
@@ -0,0 +1,444 @@
+.material-trace-header {
+  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+}
+
+.mode-tab-row {
+  display: flex;
+  gap: 0;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  overflow: hidden;
+  width: fit-content;
+}
+
+.mode-tab {
+  padding: 7px 16px;
+  border: none;
+  background: #f8fafc;
+  font-size: 13px;
+  font-weight: 600;
+  color: #475569;
+  cursor: pointer;
+  transition: background 0.15s, color 0.15s;
+}
+
+.mode-tab:not(:last-child) {
+  border-right: 1px solid var(--border);
+}
+
+.mode-tab.active {
+  background: #667eea;
+  color: #fff;
+}
+
+.mode-tab:hover:not(.active) {
+  background: #eef2f7;
+}
+
+.input-type-row {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.input-type-select {
+  width: auto;
+  min-width: 120px;
+  max-width: 180px;
+  padding: 6px 10px;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  font-size: 13px;
+  background: #fff;
+}
+
+.filter-textarea {
+  resize: vertical;
+  font-family: monospace;
+  line-height: 1.5;
+}
+
+.input-count {
+  font-size: 12px;
+  color: #64748b;
+  margin-top: 4px;
+}
+
+.input-count.over-limit {
+  color: #dc2626;
+  font-weight: 600;
+}
+
+.card {
+  background: var(--card-bg);
+  border-radius: 10px;
+  box-shadow: var(--shadow);
+  overflow: visible;
+  margin-bottom: 14px;
+}
+
+.card-header {
+  padding: 14px 18px;
+  border-bottom: 1px solid var(--border);
+  background: #f8fafc;
+  border-radius: 10px 10px 0 0;
+}
+
+.card-title {
+  font-size: 15px;
+  font-weight: 700;
+  color: #0f172a;
+}
+
+.card-body {
+  padding: 14px 16px;
+}
+
+.error-banner {
+  margin-bottom: 14px;
+  padding: 10px 12px;
+  border-radius: 6px;
+  background: #fef2f2;
+  color: #991b1b;
+  font-size: 13px;
+}
+
+.warning-banner {
+  margin-bottom: 14px;
+  padding: 10px 12px;
+  border-radius: 6px;
+  background: #fffbeb;
+  color: #b45309;
+  font-size: 13px;
+}
+
+.filter-panel {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 14px;
+  align-items: end;
+}
+
+.filter-group {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.filter-group-full {
+  grid-column: 1 / -1;
+}
+
+.filter-label {
+  font-size: 12px;
+  font-weight: 700;
+  color: #475569;
+}
+
+.filter-input {
+  width: 100%;
+  padding: 8px 10px;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  font-size: 13px;
+  background: #fff;
+}
+
+.filter-input:focus {
+  outline: none;
+  border-color: #0ea5e9;
+  box-shadow: 0 0 0 2px rgba(14, 165, 233, 0.18);
+}
+
+.filter-toolbar {
+  grid-column: 1 / -1;
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  flex-wrap: wrap;
+}
+
+.filter-actions {
+  display: flex;
+  gap: 10px;
+  flex-shrink: 0;
+}
+
+.detail-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 12px;
+}
+
+.detail-table th,
+.detail-table td {
+  border-bottom: 1px solid var(--border);
+  padding: 8px 10px;
+  text-align: left;
+  vertical-align: middle;
+  white-space: nowrap;
+}
+
+.detail-table thead th {
+  position: sticky;
+  top: 0;
+  background: #f8fafc;
+  z-index: 1;
+}
+
+.detail-table tbody tr:hover {
+  background: #f8fbff;
+}
+
+.detail-table-wrap {
+  position: relative;
+  overflow: auto;
+  max-height: 70vh;
+}
+
+.detail-table-wrap.is-loading table {
+  opacity: 0.4;
+  pointer-events: none;
+  transition: opacity 0.15s ease;
+}
+
+.table-loading-overlay {
+  position: absolute;
+  inset: 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: 2;
+}
+
+.table-spinner {
+  display: block;
+  width: 28px;
+  height: 28px;
+  border: 3px solid #d1d5db;
+  border-top-color: #667eea;
+  border-radius: 50%;
+  animation: spin 0.6s linear infinite;
+}
+
+.btn-spinner {
+  display: inline-block;
+  width: 12px;
+  height: 12px;
+  border: 2px solid rgba(255, 255, 255, 0.4);
+  border-top-color: #fff;
+  border-radius: 50%;
+  animation: spin 0.6s linear infinite;
+  margin-right: 6px;
+  vertical-align: middle;
+}
+
+@keyframes spin {
+  to { transform: rotate(360deg); }
+}
+
+.pagination-bar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 10px 0;
+  font-size: 13px;
+  color: #475569;
+}
+
+.pagination-info {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.pagination-actions {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.pagination-actions button {
+  padding: 5px 12px;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  background: #fff;
+  color: #334155;
+  font-size: 13px;
+  cursor: pointer;
+}
+
+.pagination-actions button:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+}
+
+.pagination-actions button:hover:not(:disabled) {
+  background: #f1f5f9;
+}
+
+.btn.btn-export {
+  background: #667eea;
+  color: #fff;
+}
+
+.btn.btn-export:hover {
+  background: #5568d3;
+  color: #fff;
+}
+
+.btn.btn-export:disabled {
+  opacity: 0.7;
+  cursor: not-allowed;
+}
+
+.empty-message {
+  text-align: center;
+  padding: 40px 20px;
+  color: #94a3b8;
+  font-size: 14px;
+}
+
+/* Multi-select (copied from reject-history for standalone use) */
+
+.multi-select {
+  position: relative;
+  min-width: 160px;
+}
+
+.multi-select-trigger {
+  width: 100%;
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 8px;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  padding: 8px 10px;
+  font-size: 13px;
+  color: #1f2937;
+  background: #ffffff;
+  cursor: pointer;
+}
+
+.multi-select-trigger:disabled {
+  cursor: not-allowed;
+  opacity: 0.7;
+}
+
+.multi-select-text {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  text-align: left;
+}
+
+.multi-select-arrow {
+  color: #64748b;
+  font-size: 11px;
+}
+
+.multi-select-dropdown {
+  position: absolute;
+  top: calc(100% + 4px);
+  left: 0;
+  right: 0;
+  z-index: 20;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  background: #ffffff;
+  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.14);
+  overflow: hidden;
+}
+
+.multi-select-search {
+  display: block;
+  width: 100%;
+  border: none;
+  border-bottom: 1px solid var(--border);
+  padding: 8px 12px;
+  font-size: 13px;
+  color: #1f2937;
+  outline: none;
+  background: #f8fafc;
+}
+
+.multi-select-search::placeholder {
+  color: #94a3b8;
+}
+
+.multi-select-options {
+  max-height: 250px;
+  overflow-y: auto;
+  padding: 8px 0;
+}
+
+.multi-select-option {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  width: 100%;
+  padding: 6px 12px;
+  border: none;
+  background: transparent;
+  font-size: 13px;
+  color: #334155;
+  cursor: pointer;
+  text-align: left;
+}
+
+.multi-select-option:hover {
+  background: #f8fafc;
+}
+
+.multi-select-option input[type='checkbox'] {
+  margin: 0;
+  width: 14px;
+  height: 14px;
+  accent-color: #667eea;
+}
+
+.multi-select-empty {
+  padding: 12px;
+  text-align: center;
+  color: #94a3b8;
+  font-size: 13px;
+}
+
+.multi-select-actions {
+  display: flex;
+  gap: 8px;
+  padding: 8px 10px;
+  border-top: 1px solid var(--border);
+  background: #f8fafc;
+}
+
+.btn-sm {
+  padding: 4px 10px;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  background: #f8fafc;
+  color: var(--text);
+  cursor: pointer;
+  font-size: 12px;
+}
+
+.btn-sm:hover {
+  border-color: #c2d0e0;
+  background: #eef4fb;
+}
+
+@media (max-width: 768px) {
+  .filter-panel {
+    grid-template-columns: 1fr;
+  }
+
+  .filter-group-full {
+    grid-column: span 1;
+  }
+
+  .filter-toolbar {
+    flex-direction: column;
+    align-items: flex-start;
+  }
+}
diff --git a/frontend/src/portal-shell/nativeModuleRegistry.js b/frontend/src/portal-shell/nativeModuleRegistry.js
index 57ef514..13d1f83 100644
--- a/frontend/src/portal-shell/nativeModuleRegistry.js
+++ b/frontend/src/portal-shell/nativeModuleRegistry.js
@@ -70,6 +70,10 @@ const NATIVE_MODULE_LOADERS = Object.freeze({
     () => import('../mid-section-defect/App.vue'),
     [() => import('../mid-section-defect/style.css')],
   ),
+  '/material-trace': createNativeLoader(
+    () => import('../material-trace/App.vue'),
+    [() => import('../wip-shared/styles.css'), () => import('../material-trace/style.css')],
+  ),
   '/admin/performance': createNativeLoader(
     () => import('../admin-performance/App.vue'),
     [() => import('../admin-performance/style.css')],
diff --git a/frontend/src/portal-shell/routeContracts.js b/frontend/src/portal-shell/routeContracts.js
index 3e37740..02203e0 100644
--- a/frontend/src/portal-shell/routeContracts.js
+++ b/frontend/src/portal-shell/routeContracts.js
@@ -13,6 +13,7 @@ const IN_SCOPE_REPORT_ROUTES = Object.freeze([
   '/excel-query',
   '/query-tool',
   '/mid-section-defect',
+  '/material-trace',
 ]);
 
 const IN_SCOPE_ADMIN_ROUTES = Object.freeze([
@@ -230,6 +231,17 @@ const ROUTE_CONTRACTS = Object.freeze({
     scope: 'in-scope',
     compatibilityPolicy: 'redirect_to_shell_when_spa_enabled',
   }),
+  '/material-trace': buildContract({
+    route: '/material-trace',
+    routeId: 'material-trace',
+    renderMode: 'native',
+    owner: 'frontend-mes-reporting',
+    title: '原物料追溯查詢',
+    rollbackStrategy: 'fallback_to_legacy_route',
+    visibilityPolicy: 'released_or_admin',
+    scope: 'in-scope',
+    compatibilityPolicy: 'redirect_to_shell_when_spa_enabled',
+  }),
 });
 
 const REQUIRED_FIELDS = Object.freeze([
diff --git a/frontend/vite.config.js b/frontend/vite.config.js
index bd33437..39ba097 100644
--- a/frontend/vite.config.js
+++ b/frontend/vite.config.js
@@ -28,7 +28,8 @@ export default defineConfig(({ mode }) => ({
         'query-tool': resolve(__dirname, 'src/query-tool/main.js'),
         'qc-gate': resolve(__dirname, 'src/qc-gate/index.html'),
         'mid-section-defect': resolve(__dirname, 'src/mid-section-defect/index.html'),
-        'admin-performance': resolve(__dirname, 'src/admin-performance/index.html')
+        'admin-performance': resolve(__dirname, 'src/admin-performance/index.html'),
+        'material-trace': resolve(__dirname, 'src/material-trace/index.html')
       },
       output: {
         entryFileNames: '[name].js',
diff --git a/openspec/changes/archive/2026-03-03-add-material-trace-page/.openspec.yaml b/openspec/changes/archive/2026-03-03-add-material-trace-page/.openspec.yaml
new file mode 100644
index 0000000..85cf50d
--- /dev/null
+++ b/openspec/changes/archive/2026-03-03-add-material-trace-page/.openspec.yaml
@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-03-03
diff --git a/openspec/changes/archive/2026-03-03-add-material-trace-page/design.md b/openspec/changes/archive/2026-03-03-add-material-trace-page/design.md
new file mode 100644
index 0000000..6056083
--- /dev/null
+++ b/openspec/changes/archive/2026-03-03-add-material-trace-page/design.md
@@ -0,0 +1,78 @@
+## Context
+
+工程師需要查詢 LOT/工單對應的原物料消耗記錄，以及反向從原物料批號追溯使用該批料的所有 LOT。目前原物料資訊只能在 Query Tool 的 LotDetail "原物料" tab 逐筆查看（透過 `/api/trace/events?domains=["materials"]`），不支援批量輸入或反向查詢。
+
+資料來源 `DWH.DW_MES_LOTMATERIALSHISTORY` 有 1800 萬筆記錄，已建立四個索引：
+- IDX1: `CONTAINERID`（正向 LOT 查詢）
+- IDX2: `PJ_WORKORDER`（正向工單查詢）
+- IDX3: `MATERIALPARTNAME`（料號，本次不使用）
+- IDX4: `MATERIALLOTNAME`（反向原物料批號查詢）
+
+站群組（WORKCENTER_GROUP）對應由 `filter_cache.get_workcenter_mapping()` 提供，從 `DW_MES_SPEC_WORKCENTER_V` 載入，每小時刷新。
+
+## Goals / Non-Goals
+
+**Goals:**
+
+- 提供獨立頁面，支援正向（LOT ID / 工單 → 原物料）和反向（原物料批號 → LOT）雙向查詢
+- 正向查詢支援 LOT ID 和工單兩種輸入模式切換
+- 支援多筆輸入（換行/逗號分隔）
+- 結果含站群組篩選、分頁、CSV 匯出
+- 使用既有 Oracle 索引，查詢效率可控
+
+**Non-Goals:**
+
+- 不支援 MATERIALPARTNAME（料號）反向查詢（資料量風險過高，同一料號可能數萬筆）
+- 不需日期範圍篩選（以 LOT/工單/原物料批號為查詢條件即可）
+- 不做 Redis 快取或 BatchQueryEngine 分片（查詢範圍由輸入筆數控制，非時間範圍）
+- 不做 BOM 對照或原物料品質統計
+
+## Decisions
+
+### D1: 使用 `read_sql_df`（pooled connection）而非 `read_sql_df_slow`
+
+**決定**: 查詢使用 pooled connection（`read_sql_df`），不走 slow query path。
+
+**理由**: 此查詢依賴索引命中，預期回應時間 < 5s。不像 reject-history 的全表掃描需要 dedicated connection。正向查詢最多幾千筆結果，反向查詢設結果上限 10,000 筆。
+
+**替代方案**: 使用 `read_sql_df_slow`。
+**為何不採用**: 佔用 slow query semaphore 會排擠需要長時間執行的查詢（reject-history、resource-history）。
+
+### D2: 正向查詢先解析 LOT ID → CONTAINERID
+
+**決定**: LOT ID 輸入模式需要先將 CONTAINERNAME 轉換為 CONTAINERID（16-char hex），因為 `LOTMATERIALSHISTORY` 的索引是 CONTAINERID。使用 `DW_MES_CONTAINER` 做 batch lookup。工單模式直接查 `PJ_WORKORDER` 索引，不需轉換。
+
+**理由**: 使用者輸入的是可讀的 LOT 名稱（如 GA25060001-A01），但資料表索引是 CONTAINERID。直接 JOIN 會讓 optimizer 可能選擇低效計畫。先 batch resolve 再用 IN clause 更可預測。
+
+**替代方案**: SQL 內直接 JOIN CONTAINER 表。
+**為何不採用**: 對於多筆 LOT 輸入，兩步驟（resolve + query）的執行計畫更穩定，且 resolve 結果可重用於顯示。
+
+### D3: 站群組篩選在後端 enrichment 而非 SQL WHERE
+
+**決定**: SQL 查詢不加 WORKCENTERNAME 過濾。查詢結果回來後，後端用 `get_workcenter_mapping()` 對每列添加 `WORKCENTER_GROUP` 欄位，前端可做篩選。若使用者選了站群組篩選，後端先 resolve 站群組 → WORKCENTERNAME 清單，再在 SQL 加 `AND WORKCENTERNAME IN (...)` 過濾。
+
+**理由**: 如果不篩選，使用者能看到所有站點的資料（含站群組欄位）。如果篩選了，SQL 層就縮減結果集，減少傳輸和分頁壓力。
+
+### D4: 反向查詢結果數上限 10,000 筆
+
+**決定**: 反向查詢（原物料批號 → LOT）加入 `FETCH FIRST 10001 ROWS ONLY` 上限。若回傳超過 10,000 筆，前端顯示警告「結果超過上限，請縮小查詢範圍」。
+
+**理由**: 一批常用原物料可能被上千個 LOT 使用。無上限的反向查詢可能回傳數萬筆，壓垮前端和 Oracle 連線。10,000 筆足以覆蓋絕大多數場景。
+
+### D5: 前端頁面結構沿用 Vite multi-page 模式
+
+**決定**: 新增 `frontend/material-trace.html` + `frontend/src/material-trace/App.vue` 作為獨立 Vite entry point。沿用 reject-history 的單檔 App.vue + 子元件模式。
+
+**理由**: 專案的所有查詢頁面（reject-history、hold-history、resource-history）都是獨立 Vite entry。統一架構。
+
+### D6: 輸入筆數上限
+
+**決定**: 正向查詢（LOT ID / 工單）輸入上限 200 筆，反向查詢（原物料批號）輸入上限 50 筆。
+
+**理由**: 正向查詢每筆 LOT 平均產生 10-50 筆原物料記錄，200 筆 LOT 最多 10,000 筆結果。反向查詢每批原物料可能對應 100-1000 個 LOT，50 批已有碰上 10,000 筆上限的風險。
+
+## Risks / Trade-offs
+
+- **[低] CONTAINERID resolve 多一次 round-trip** — LOT ID 模式需先查 `DW_MES_CONTAINER` 轉換。→ Container 表有 CONTAINERNAME 索引，batch IN query 很快（< 1s）。
+- **[低] 站群組 mapping 可能未涵蓋所有 WORKCENTERNAME** — `DW_MES_SPEC_WORKCENTER_V` 可能缺少新站點。→ 未映射的站點在結果中站群組欄位顯示空值，不影響查詢結果。
+- **[中] 反向查詢結果截斷** — 10,000 筆上限可能截斷大量使用的原物料批號結果。→ 前端明確顯示截斷警告，引導使用者縮小範圍。
diff --git a/openspec/changes/archive/2026-03-03-add-material-trace-page/proposal.md b/openspec/changes/archive/2026-03-03-add-material-trace-page/proposal.md
new file mode 100644
index 0000000..342990d
--- /dev/null
+++ b/openspec/changes/archive/2026-03-03-add-material-trace-page/proposal.md
@@ -0,0 +1,35 @@
+## Why
+
+生產追溯過程中，工程師需要查詢「某個 LOT/工單在哪個站群組用了什麼原物料」以及「某批原物料被哪些 LOT 使用」。目前原物料消耗資訊散落在 Query Tool 的 LotDetail "原物料" tab 中，只能逐筆 LOT 查看，無法批量查詢或反向追溯。缺少專屬頁面讓原物料異常時的影響範圍評估非常耗時。
+
+## What Changes
+
+- 新增「原物料追溯查詢」獨立頁面，提供雙向查詢能力：
+  - **正向查詢**：輸入 LOT ID 或工單號碼（多筆），查詢對應的原物料消耗記錄，可依站群組篩選
+  - **反向查詢**：輸入原物料批號 MATERIALLOTNAME（多筆），查詢該批原物料被哪些 LOT 使用
+- 結果表格含分頁、站群組篩選、CSV 匯出
+- 後端新增 `/api/material-trace/query` 和 `/api/material-trace/export` API 端點
+- 查詢資料來源：`DWH.DW_MES_LOTMATERIALSHISTORY`（1800 萬筆），利用既有索引（CONTAINERID, PJ_WORKORDER, MATERIALLOTNAME）
+- 站群組對應透過 `filter_cache.get_workcenter_mapping()` 解析（與設備歷史績效共用同一份 mapping）
+
+## Capabilities
+
+### New Capabilities
+
+- `material-trace-page`: 原物料追溯查詢頁面 — 前端 UI、查詢模式切換、結果表格、分頁、CSV 匯出
+- `material-trace-api`: 原物料追溯 API — 正向/反向查詢端點、輸入驗證、結果分頁、匯出端點、rate limiting
+
+### Modified Capabilities
+
+（無既有 spec 需修改）
+
+## Impact
+
+- **新增後端服務** — `src/mes_dashboard/services/material_trace_service.py`：正向/反向查詢邏輯、站群組 enrichment
+- **新增後端路由** — `src/mes_dashboard/routes/material_trace_routes.py`：API 端點註冊
+- **新增 SQL** — `src/mes_dashboard/sql/material_trace/`：3 個查詢檔（forward_by_lot、forward_by_workorder、reverse_by_material_lot）
+- **新增前端頁面** — `frontend/src/material-trace/`：App.vue + 子元件（FilterPanel、ResultTable）
+- **新增前端入口** — `frontend/material-trace.html` + Vite entry
+- **共用依賴** — `filter_cache.get_workcenter_mapping()` 提供站群組對應、`parseMultiLineInput()` 處理多筆輸入
+- **資料庫** — 查詢 `DWH.DW_MES_LOTMATERIALSHISTORY`，使用既有索引，無 schema 變更
+- **Sidebar** — 需在導覽列新增頁面入口
diff --git a/openspec/changes/archive/2026-03-03-add-material-trace-page/specs/material-trace-api/spec.md b/openspec/changes/archive/2026-03-03-add-material-trace-page/specs/material-trace-api/spec.md
new file mode 100644
index 0000000..5093e48
--- /dev/null
+++ b/openspec/changes/archive/2026-03-03-add-material-trace-page/specs/material-trace-api/spec.md
@@ -0,0 +1,120 @@
+## ADDED Requirements
+
+### Requirement: Material Trace API SHALL provide forward query endpoint
+The API SHALL accept LOT IDs or work order numbers and return corresponding material consumption records from `DW_MES_LOTMATERIALSHISTORY`.
+
+#### Scenario: Forward query by LOT ID
+- **WHEN** `POST /api/material-trace/query` is called with `mode: "lot"` and `values: ["GA25060001-A01", "GA25060502"]`
+- **THEN** the API SHALL resolve LOT names to CONTAINERIDs via `DW_MES_CONTAINER`
+- **THEN** the API SHALL return material consumption records matching those CONTAINERIDs
+- **THEN** each record SHALL include CONTAINERID, CONTAINERNAME, PJ_WORKORDER, WORKCENTERNAME, WORKCENTER_GROUP, MATERIALPARTNAME, MATERIALLOTNAME, VENDORLOTNUMBER, QTYREQUIRED, QTYCONSUMED, EQUIPMENTNAME, TXNDATE, PRIMARY_CATEGORY, SECONDARY_CATEGORY
+
+#### Scenario: Forward query by work order
+- **WHEN** `POST /api/material-trace/query` is called with `mode: "workorder"` and `values: ["WO-2025-001", "WO-2025-002"]`
+- **THEN** the API SHALL query `DW_MES_LOTMATERIALSHISTORY` using `PJ_WORKORDER` index directly
+- **THEN** the response format SHALL be identical to LOT ID mode
+
+#### Scenario: Forward query with workcenter group filter
+- **WHEN** `POST /api/material-trace/query` includes `workcenter_groups: ["焊接_DB"]`
+- **THEN** the API SHALL resolve group names to WORKCENTERNAME list via `filter_cache.get_workcenter_mapping()`
+- **THEN** the SQL query SHALL include `AND WORKCENTERNAME IN (...)` filter
+- **THEN** results SHALL only contain records from workcenters belonging to the selected groups
+
+#### Scenario: Forward query input limit
+- **WHEN** `POST /api/material-trace/query` with `mode: "lot"` or `mode: "workorder"` contains more than 200 values
+- **THEN** the API SHALL return HTTP 400 with error message indicating the 200-value limit
+
+### Requirement: Material Trace API SHALL provide reverse query endpoint
+The API SHALL accept material lot names and return LOTs that consumed those materials.
+
+#### Scenario: Reverse query by material lot name
+- **WHEN** `POST /api/material-trace/query` is called with `mode: "material_lot"` and `values: ["WIRE-LOT-20250101-A"]`
+- **THEN** the API SHALL query `DW_MES_LOTMATERIALSHISTORY` using `MATERIALLOTNAME` index
+- **THEN** each record SHALL include the same fields as forward query results
+
+#### Scenario: Reverse query with workcenter group filter
+- **WHEN** reverse query includes `workcenter_groups` parameter
+- **THEN** the same workcenter group filtering logic as forward query SHALL apply
+
+#### Scenario: Reverse query input limit
+- **WHEN** `POST /api/material-trace/query` with `mode: "material_lot"` contains more than 50 values
+- **THEN** the API SHALL return HTTP 400 with error message indicating the 50-value limit
+
+#### Scenario: Reverse query result limit
+- **WHEN** reverse query results exceed 10,000 rows
+- **THEN** the API SHALL return exactly 10,000 rows
+- **THEN** the response `meta` SHALL include `truncated: true` and `max_rows: 10000`
+
+### Requirement: Material Trace API SHALL validate query parameters
+The API SHALL validate input parameters before executing database queries.
+
+#### Scenario: Missing required fields
+- **WHEN** `POST /api/material-trace/query` is called without `mode` or `values`
+- **THEN** the API SHALL return HTTP 400 with descriptive validation error
+
+#### Scenario: Invalid mode
+- **WHEN** `mode` is not one of `lot`, `workorder`, `material_lot`
+- **THEN** the API SHALL return HTTP 400
+
+#### Scenario: Empty values
+- **WHEN** `values` is an empty array or all values are blank after trimming
+- **THEN** the API SHALL return HTTP 400 with error message "請輸入至少一筆查詢條件"
+
+#### Scenario: Unresolvable LOT IDs
+- **WHEN** some LOT names cannot be resolved to CONTAINERIDs
+- **THEN** the API SHALL proceed with the resolved subset
+- **THEN** the response `meta` SHALL include `unresolved` array listing unresolvable LOT names
+
+### Requirement: Material Trace API SHALL support paginated results
+The API SHALL support server-side pagination for query results.
+
+#### Scenario: Pagination parameters
+- **WHEN** `POST /api/material-trace/query` includes `page` and `per_page`
+- **THEN** results SHALL be paginated accordingly
+- **THEN** response SHALL include `pagination: { page, per_page, total, total_pages }`
+
+#### Scenario: Default pagination
+- **WHEN** `page` or `per_page` is not provided
+- **THEN** `page` SHALL default to 1
+- **THEN** `per_page` SHALL default to 50
+
+#### Scenario: Per-page cap
+- **WHEN** `per_page` exceeds 200
+- **THEN** `per_page` SHALL be capped at 200
+
+### Requirement: Material Trace API SHALL provide CSV export endpoint
+The API SHALL provide CSV export using the same query parameters as the query endpoint.
+
+#### Scenario: Export request
+- **WHEN** `POST /api/material-trace/export` is called with the same parameters as query
+- **THEN** the response SHALL be a CSV file with UTF-8 BOM encoding
+- **THEN** CSV headers SHALL be in Chinese
+- **THEN** all matching records SHALL be included (no pagination, subject to result limits)
+
+#### Scenario: Export result limit
+- **WHEN** export results exceed 50,000 rows
+- **THEN** the export SHALL be truncated at 50,000 rows
+- **THEN** a warning header SHALL indicate truncation
+
+### Requirement: Material Trace API SHALL enrich results with workcenter group
+The API SHALL add WORKCENTER_GROUP to each result row based on `filter_cache.get_workcenter_mapping()`.
+
+#### Scenario: Workcenter group enrichment
+- **WHEN** query results are returned
+- **THEN** each row SHALL include a `WORKCENTER_GROUP` field
+- **THEN** the value SHALL be resolved from `filter_cache.get_workcenter_mapping()` using the row's `WORKCENTERNAME`
+
+#### Scenario: Unknown workcenter
+- **WHEN** a row's WORKCENTERNAME has no mapping in the workcenter cache
+- **THEN** `WORKCENTER_GROUP` SHALL be empty string
+
+### Requirement: Material Trace API SHALL apply rate limiting
+The API SHALL rate-limit query and export endpoints to protect Oracle resources.
+
+#### Scenario: Query rate limit
+- **WHEN** `/api/material-trace/query` receives excessive requests
+- **THEN** requests beyond 30 per 60 seconds SHALL be rejected with HTTP 429
+
+#### Scenario: Export rate limit
+- **WHEN** `/api/material-trace/export` receives excessive requests
+- **THEN** requests beyond 10 per 60 seconds SHALL be rejected with HTTP 429
diff --git a/openspec/changes/archive/2026-03-03-add-material-trace-page/specs/material-trace-page/spec.md b/openspec/changes/archive/2026-03-03-add-material-trace-page/specs/material-trace-page/spec.md
new file mode 100644
index 0000000..92c83a1
--- /dev/null
+++ b/openspec/changes/archive/2026-03-03-add-material-trace-page/specs/material-trace-page/spec.md
@@ -0,0 +1,120 @@
+## ADDED Requirements
+
+### Requirement: Material Trace page SHALL provide bidirectional query mode switching
+The page SHALL provide two query directions with explicit tab switching.
+
+#### Scenario: Forward query mode (default)
+- **WHEN** the page loads
+- **THEN** "正向查詢：LOT/工單 → 原物料" tab SHALL be active by default
+- **THEN** the input area SHALL show input type selector (LOT ID / 工單) and a multi-line text input
+
+#### Scenario: Reverse query mode
+- **WHEN** user clicks "反向查詢：原物料 → LOT" tab
+- **THEN** the input area SHALL switch to material lot name multi-line input
+- **THEN** query results and pagination SHALL be cleared
+
+#### Scenario: Forward input type switching
+- **WHEN** forward mode is active
+- **THEN** user SHALL be able to switch between "LOT ID" and "工單" input types
+- **THEN** switching input type SHALL clear the input field and results
+
+### Requirement: Material Trace page SHALL accept multi-line input
+The page SHALL accept multiple values separated by newlines or commas.
+
+#### Scenario: Multi-line input parsing
+- **WHEN** user enters values separated by newlines, commas, or mixed delimiters
+- **THEN** the system SHALL parse and deduplicate values using the same logic as `parseMultiLineInput()`
+
+#### Scenario: Input count display
+- **WHEN** user enters values
+- **THEN** the input area SHALL display the parsed count (e.g., "已輸入 5 筆")
+
+#### Scenario: Forward input limit feedback
+- **WHEN** user enters more than 200 values in forward mode
+- **THEN** the page SHALL display an error message "正向查詢上限 200 筆"
+- **THEN** the query SHALL NOT be sent
+
+#### Scenario: Reverse input limit feedback
+- **WHEN** user enters more than 50 values in reverse mode
+- **THEN** the page SHALL display an error message "反向查詢上限 50 筆"
+- **THEN** the query SHALL NOT be sent
+
+### Requirement: Material Trace page SHALL provide workcenter group filter
+The page SHALL allow filtering results by workcenter group.
+
+#### Scenario: Workcenter group options
+- **WHEN** the page loads
+- **THEN** workcenter group filter SHALL be populated from `filter_cache.get_workcenter_groups()`
+- **THEN** the filter SHALL support multi-select
+- **THEN** default SHALL be "全部站點" (no filter)
+
+#### Scenario: Filter applied to query
+- **WHEN** user selects workcenter groups and clicks "查詢"
+- **THEN** the selected groups SHALL be sent as `workcenter_groups` parameter to the API
+- **THEN** results SHALL only contain records from workcenters in the selected groups
+
+### Requirement: Material Trace page SHALL display query results in a paginated table
+The page SHALL display results in a sortable, paginated detail table.
+
+#### Scenario: Result table columns
+- **WHEN** query results are loaded
+- **THEN** the table SHALL display: LOT ID (CONTAINERNAME), 工單 (PJ_WORKORDER), 站群組 (WORKCENTER_GROUP), 站點 (WORKCENTERNAME), 料號 (MATERIALPARTNAME), 物料批號 (MATERIALLOTNAME), 供應商批號 (VENDORLOTNUMBER), 應領量 (QTYREQUIRED), 實際消耗 (QTYCONSUMED), 機台 (EQUIPMENTNAME), 交易日期 (TXNDATE), 主分類 (PRIMARY_CATEGORY), 副分類 (SECONDARY_CATEGORY)
+
+#### Scenario: Pagination controls
+- **WHEN** results exceed per-page size
+- **THEN** pagination controls SHALL display "上一頁" / "下一頁" buttons and page info in Chinese
+- **THEN** default per-page size SHALL be 50
+
+#### Scenario: Empty results
+- **WHEN** query returns no matching records
+- **THEN** the table area SHALL display "查無資料" message
+
+#### Scenario: Unresolved LOT IDs warning
+- **WHEN** the API response contains `meta.unresolved` array
+- **THEN** a warning banner SHALL display listing the unresolvable LOT names
+
+#### Scenario: Result truncation warning
+- **WHEN** the API response contains `meta.truncated: true`
+- **THEN** an amber warning banner SHALL display "查詢結果超過 10,000 筆上限，請縮小查詢範圍"
+
+### Requirement: Material Trace page SHALL support CSV export
+The page SHALL allow exporting current query results to CSV.
+
+#### Scenario: Export button
+- **WHEN** query results are loaded
+- **THEN** an "匯出 CSV" button SHALL be visible
+- **WHEN** user clicks "匯出 CSV"
+- **THEN** the export request SHALL use the same query parameters as the current query
+
+#### Scenario: Export disabled without results
+- **WHEN** no query has been executed or results are empty
+- **THEN** the "匯出 CSV" button SHALL be disabled
+
+### Requirement: Material Trace page SHALL provide loading and error states
+The page SHALL provide clear feedback during loading and error conditions.
+
+#### Scenario: Loading state
+- **WHEN** a query is in progress
+- **THEN** a loading indicator SHALL be visible
+- **THEN** the query button SHALL be disabled
+
+#### Scenario: API error
+- **WHEN** the API returns an error
+- **THEN** a red error banner SHALL display the error message
+
+#### Scenario: Error cleared on new query
+- **WHEN** user initiates a new query
+- **THEN** previous error and warning banners SHALL be cleared
+
+### Requirement: Material Trace page SHALL use Chinese labels
+The page SHALL display all UI text in Traditional Chinese consistent with the rest of the application.
+
+#### Scenario: Page title
+- **WHEN** the page is rendered
+- **THEN** the page title SHALL be "原物料追溯查詢"
+
+#### Scenario: Button labels
+- **WHEN** the page is rendered
+- **THEN** the query button SHALL display "查詢"
+- **THEN** the export button SHALL display "匯出 CSV"
+- **THEN** the clear button SHALL display "清除"
diff --git a/openspec/changes/archive/2026-03-03-add-material-trace-page/tasks.md b/openspec/changes/archive/2026-03-03-add-material-trace-page/tasks.md
new file mode 100644
index 0000000..79b7753
--- /dev/null
+++ b/openspec/changes/archive/2026-03-03-add-material-trace-page/tasks.md
@@ -0,0 +1,63 @@
+## 1. SQL 查詢檔
+
+- [x] 1.1 建立 `src/mes_dashboard/sql/material_trace/` 目錄
+- [x] 1.2 新增 `forward_by_lot.sql`：以 CONTAINERID IN (:ids) 查詢 `DW_MES_LOTMATERIALSHISTORY`，LEFT JOIN `DW_MES_CONTAINER` 取 CONTAINERNAME，含可選 WORKCENTERNAME IN 篩選
+- [x] 1.3 新增 `forward_by_workorder.sql`：以 PJ_WORKORDER IN (:ids) 查詢，結構與 forward_by_lot 相同
+- [x] 1.4 新增 `reverse_by_material_lot.sql`：以 MATERIALLOTNAME IN (:ids) 查詢，LEFT JOIN `DW_MES_CONTAINER` 取 CONTAINERNAME，含 FETCH FIRST 10001 ROWS ONLY 上限，含可選 WORKCENTERNAME IN 篩選
+- [x] 1.5 新增 `resolve_container_ids.sql`：批次將 CONTAINERNAME 轉換為 CONTAINERID
+
+## 2. 後端 Service
+
+- [x] 2.1 新增 `src/mes_dashboard/services/material_trace_service.py`，包含 `forward_query(mode, values, workcenter_groups, page, per_page)` 函式
+- [x] 2.2 在 `forward_query` 中實作 LOT ID 模式：呼叫 `resolve_container_ids.sql` 將 CONTAINERNAME 批次轉換為 CONTAINERID，記錄未解析的名稱到 `meta.unresolved`
+- [x] 2.3 在 `forward_query` 中實作工單模式：直接以 PJ_WORKORDER 查詢
+- [x] 2.4 實作 `reverse_query(values, workcenter_groups, page, per_page)` 函式，以 MATERIALLOTNAME 查詢，檢查結果是否超過 10,000 筆並設定 `meta.truncated`
+- [x] 2.5 實作共用 `_enrich_workcenter_group(df)` 函式：使用 `filter_cache.get_workcenter_mapping()` 對 DataFrame 添加 WORKCENTER_GROUP 欄位
+- [x] 2.6 實作共用 `_apply_workcenter_group_filter(workcenter_groups)` 函式：透過 `filter_cache.get_workcenter_mapping()` 將站群組名稱解析為 WORKCENTERNAME 清單，供 SQL WHERE 使用
+- [x] 2.7 實作 `export_csv(mode, values, workcenter_groups)` 函式，結果上限 50,000 筆，回傳 UTF-8 BOM CSV
+
+## 3. 後端 Route
+
+- [x] 3.1 新增 `src/mes_dashboard/routes/material_trace_routes.py`，建立 `material_trace_bp` Blueprint，prefix `/api/material-trace`
+- [x] 3.2 實作 `POST /query` 端點：驗證 mode（lot/workorder/material_lot）、values 非空、筆數上限（正向 200 / 反向 50）；根據 mode 呼叫 `forward_query` 或 `reverse_query`；回傳分頁結果
+- [x] 3.3 實作 `POST /export` 端點：與 query 相同參數驗證，呼叫 `export_csv`，回傳 CSV response
+- [x] 3.4 實作 `GET /filter-options` 端點：回傳 `filter_cache.get_workcenter_groups()` 供前端站群組下拉選單使用
+- [x] 3.5 加入 rate limiting：query 30/60s，export 10/60s
+- [x] 3.6 在 `routes/__init__.py` 註冊 `material_trace_bp`
+
+## 4. 前端頁面基礎
+
+- [x] 4.1 新增 `frontend/material-trace.html` Vite entry point
+- [x] 4.2 新增 `frontend/src/material-trace/main.js` 初始化 Vue app
+- [x] 4.3 新增 `frontend/src/material-trace/App.vue` 主元件：包含 queryMode（forward/reverse）、forwardInputType（lot/workorder）、inputText、workcenterGroups、results、pagination、loading、error 等 reactive state
+- [x] 4.4 新增 `frontend/src/material-trace/style.css`，沿用 reject-history 的表格/banner 樣式基礎
+- [x] 4.5 在 `vite.config.js` 加入 `material-trace` entry
+- [x] 4.6 在 Flask 後端 `templates/` 新增頁面路由（或 Jinja template），確認頁面可存取
+
+## 5. 前端元件
+
+- [x] 5.1 實作查詢模式切換 tab（正向查詢 / 反向查詢），切換時清空輸入和結果
+- [x] 5.2 實作正向模式的輸入類型選擇（LOT ID / 工單），切換時清空輸入
+- [x] 5.3 實作多筆輸入 textarea，使用 `parseMultiLineInput()` 解析，顯示已輸入筆數
+- [x] 5.4 實作前端輸入筆數驗證（正向 200 筆 / 反向 50 筆），超過時顯示 error banner 並阻止查詢
+- [x] 5.5 實作站群組多選篩選下拉（options 從 `/api/material-trace/filter-options` 載入）
+- [x] 5.6 實作 `executePrimaryQuery()` 函式：呼叫 `/api/material-trace/query` API，處理結果、分頁、error、unresolved、truncated 警告
+- [x] 5.7 實作結果表格，含 13 個欄位（CONTAINERNAME、PJ_WORKORDER、WORKCENTER_GROUP、WORKCENTERNAME、MATERIALPARTNAME、MATERIALLOTNAME、VENDORLOTNUMBER、QTYREQUIRED、QTYCONSUMED、EQUIPMENTNAME、TXNDATE、PRIMARY_CATEGORY、SECONDARY_CATEGORY）
+- [x] 5.8 實作分頁控制（上一頁/下一頁/頁碼顯示），server-side 分頁
+- [x] 5.9 實作匯出 CSV 按鈕，呼叫 `/api/material-trace/export`，無結果時 disabled
+- [x] 5.10 實作 loading overlay、error banner、warning banner（unresolved LOT / 結果截斷）
+
+## 6. 導覽整合
+
+- [x] 6.1 在 sidebar/drawer 導覽列新增「原物料追溯查詢」頁面入口
+
+## 7. 測試
+
+- [x] 7.1 新增 `tests/test_material_trace_service.py`：測試正向 LOT 模式查詢（mock Oracle 回傳），驗證 CONTAINERID resolve + 結果 enrichment
+- [x] 7.2 測試正向工單模式查詢，驗證 PJ_WORKORDER 直接查詢
+- [x] 7.3 測試反向查詢，驗證結果上限 10,000 筆截斷邏輯
+- [x] 7.4 測試站群組篩選：mock `get_workcenter_mapping()` 回傳 mapping，驗證 WORKCENTERNAME IN 過濾
+- [x] 7.5 測試未解析 LOT ID 的 `meta.unresolved` 回傳
+- [x] 7.6 新增 `tests/test_material_trace_routes.py`：測試輸入驗證（mode 無效、values 空、超過筆數上限）回傳 HTTP 400
+- [x] 7.7 測試 query 端點回傳正確分頁結構
+- [x] 7.8 測試 export 端點回傳 CSV content-type 和 UTF-8 BOM
diff --git a/openspec/specs/material-trace-api/spec.md b/openspec/specs/material-trace-api/spec.md
new file mode 100644
index 0000000..5093e48
--- /dev/null
+++ b/openspec/specs/material-trace-api/spec.md
@@ -0,0 +1,120 @@
+## ADDED Requirements
+
+### Requirement: Material Trace API SHALL provide forward query endpoint
+The API SHALL accept LOT IDs or work order numbers and return corresponding material consumption records from `DW_MES_LOTMATERIALSHISTORY`.
+
+#### Scenario: Forward query by LOT ID
+- **WHEN** `POST /api/material-trace/query` is called with `mode: "lot"` and `values: ["GA25060001-A01", "GA25060502"]`
+- **THEN** the API SHALL resolve LOT names to CONTAINERIDs via `DW_MES_CONTAINER`
+- **THEN** the API SHALL return material consumption records matching those CONTAINERIDs
+- **THEN** each record SHALL include CONTAINERID, CONTAINERNAME, PJ_WORKORDER, WORKCENTERNAME, WORKCENTER_GROUP, MATERIALPARTNAME, MATERIALLOTNAME, VENDORLOTNUMBER, QTYREQUIRED, QTYCONSUMED, EQUIPMENTNAME, TXNDATE, PRIMARY_CATEGORY, SECONDARY_CATEGORY
+
+#### Scenario: Forward query by work order
+- **WHEN** `POST /api/material-trace/query` is called with `mode: "workorder"` and `values: ["WO-2025-001", "WO-2025-002"]`
+- **THEN** the API SHALL query `DW_MES_LOTMATERIALSHISTORY` using `PJ_WORKORDER` index directly
+- **THEN** the response format SHALL be identical to LOT ID mode
+
+#### Scenario: Forward query with workcenter group filter
+- **WHEN** `POST /api/material-trace/query` includes `workcenter_groups: ["焊接_DB"]`
+- **THEN** the API SHALL resolve group names to WORKCENTERNAME list via `filter_cache.get_workcenter_mapping()`
+- **THEN** the SQL query SHALL include `AND WORKCENTERNAME IN (...)` filter
+- **THEN** results SHALL only contain records from workcenters belonging to the selected groups
+
+#### Scenario: Forward query input limit
+- **WHEN** `POST /api/material-trace/query` with `mode: "lot"` or `mode: "workorder"` contains more than 200 values
+- **THEN** the API SHALL return HTTP 400 with error message indicating the 200-value limit
+
+### Requirement: Material Trace API SHALL provide reverse query endpoint
+The API SHALL accept material lot names and return LOTs that consumed those materials.
+
+#### Scenario: Reverse query by material lot name
+- **WHEN** `POST /api/material-trace/query` is called with `mode: "material_lot"` and `values: ["WIRE-LOT-20250101-A"]`
+- **THEN** the API SHALL query `DW_MES_LOTMATERIALSHISTORY` using `MATERIALLOTNAME` index
+- **THEN** each record SHALL include the same fields as forward query results
+
+#### Scenario: Reverse query with workcenter group filter
+- **WHEN** reverse query includes `workcenter_groups` parameter
+- **THEN** the same workcenter group filtering logic as forward query SHALL apply
+
+#### Scenario: Reverse query input limit
+- **WHEN** `POST /api/material-trace/query` with `mode: "material_lot"` contains more than 50 values
+- **THEN** the API SHALL return HTTP 400 with error message indicating the 50-value limit
+
+#### Scenario: Reverse query result limit
+- **WHEN** reverse query results exceed 10,000 rows
+- **THEN** the API SHALL return exactly 10,000 rows
+- **THEN** the response `meta` SHALL include `truncated: true` and `max_rows: 10000`
+
+### Requirement: Material Trace API SHALL validate query parameters
+The API SHALL validate input parameters before executing database queries.
+
+#### Scenario: Missing required fields
+- **WHEN** `POST /api/material-trace/query` is called without `mode` or `values`
+- **THEN** the API SHALL return HTTP 400 with descriptive validation error
+
+#### Scenario: Invalid mode
+- **WHEN** `mode` is not one of `lot`, `workorder`, `material_lot`
+- **THEN** the API SHALL return HTTP 400
+
+#### Scenario: Empty values
+- **WHEN** `values` is an empty array or all values are blank after trimming
+- **THEN** the API SHALL return HTTP 400 with error message "請輸入至少一筆查詢條件"
+
+#### Scenario: Unresolvable LOT IDs
+- **WHEN** some LOT names cannot be resolved to CONTAINERIDs
+- **THEN** the API SHALL proceed with the resolved subset
+- **THEN** the response `meta` SHALL include `unresolved` array listing unresolvable LOT names
+
+### Requirement: Material Trace API SHALL support paginated results
+The API SHALL support server-side pagination for query results.
+
+#### Scenario: Pagination parameters
+- **WHEN** `POST /api/material-trace/query` includes `page` and `per_page`
+- **THEN** results SHALL be paginated accordingly
+- **THEN** response SHALL include `pagination: { page, per_page, total, total_pages }`
+
+#### Scenario: Default pagination
+- **WHEN** `page` or `per_page` is not provided
+- **THEN** `page` SHALL default to 1
+- **THEN** `per_page` SHALL default to 50
+
+#### Scenario: Per-page cap
+- **WHEN** `per_page` exceeds 200
+- **THEN** `per_page` SHALL be capped at 200
+
+### Requirement: Material Trace API SHALL provide CSV export endpoint
+The API SHALL provide CSV export using the same query parameters as the query endpoint.
+
+#### Scenario: Export request
+- **WHEN** `POST /api/material-trace/export` is called with the same parameters as query
+- **THEN** the response SHALL be a CSV file with UTF-8 BOM encoding
+- **THEN** CSV headers SHALL be in Chinese
+- **THEN** all matching records SHALL be included (no pagination, subject to result limits)
+
+#### Scenario: Export result limit
+- **WHEN** export results exceed 50,000 rows
+- **THEN** the export SHALL be truncated at 50,000 rows
+- **THEN** a warning header SHALL indicate truncation
+
+### Requirement: Material Trace API SHALL enrich results with workcenter group
+The API SHALL add WORKCENTER_GROUP to each result row based on `filter_cache.get_workcenter_mapping()`.
+
+#### Scenario: Workcenter group enrichment
+- **WHEN** query results are returned
+- **THEN** each row SHALL include a `WORKCENTER_GROUP` field
+- **THEN** the value SHALL be resolved from `filter_cache.get_workcenter_mapping()` using the row's `WORKCENTERNAME`
+
+#### Scenario: Unknown workcenter
+- **WHEN** a row's WORKCENTERNAME has no mapping in the workcenter cache
+- **THEN** `WORKCENTER_GROUP` SHALL be empty string
+
+### Requirement: Material Trace API SHALL apply rate limiting
+The API SHALL rate-limit query and export endpoints to protect Oracle resources.
+
+#### Scenario: Query rate limit
+- **WHEN** `/api/material-trace/query` receives excessive requests
+- **THEN** requests beyond 30 per 60 seconds SHALL be rejected with HTTP 429
+
+#### Scenario: Export rate limit
+- **WHEN** `/api/material-trace/export` receives excessive requests
+- **THEN** requests beyond 10 per 60 seconds SHALL be rejected with HTTP 429
diff --git a/openspec/specs/material-trace-page/spec.md b/openspec/specs/material-trace-page/spec.md
new file mode 100644
index 0000000..92c83a1
--- /dev/null
+++ b/openspec/specs/material-trace-page/spec.md
@@ -0,0 +1,120 @@
+## ADDED Requirements
+
+### Requirement: Material Trace page SHALL provide bidirectional query mode switching
+The page SHALL provide two query directions with explicit tab switching.
+
+#### Scenario: Forward query mode (default)
+- **WHEN** the page loads
+- **THEN** "正向查詢：LOT/工單 → 原物料" tab SHALL be active by default
+- **THEN** the input area SHALL show input type selector (LOT ID / 工單) and a multi-line text input
+
+#### Scenario: Reverse query mode
+- **WHEN** user clicks "反向查詢：原物料 → LOT" tab
+- **THEN** the input area SHALL switch to material lot name multi-line input
+- **THEN** query results and pagination SHALL be cleared
+
+#### Scenario: Forward input type switching
+- **WHEN** forward mode is active
+- **THEN** user SHALL be able to switch between "LOT ID" and "工單" input types
+- **THEN** switching input type SHALL clear the input field and results
+
+### Requirement: Material Trace page SHALL accept multi-line input
+The page SHALL accept multiple values separated by newlines or commas.
+
+#### Scenario: Multi-line input parsing
+- **WHEN** user enters values separated by newlines, commas, or mixed delimiters
+- **THEN** the system SHALL parse and deduplicate values using the same logic as `parseMultiLineInput()`
+
+#### Scenario: Input count display
+- **WHEN** user enters values
+- **THEN** the input area SHALL display the parsed count (e.g., "已輸入 5 筆")
+
+#### Scenario: Forward input limit feedback
+- **WHEN** user enters more than 200 values in forward mode
+- **THEN** the page SHALL display an error message "正向查詢上限 200 筆"
+- **THEN** the query SHALL NOT be sent
+
+#### Scenario: Reverse input limit feedback
+- **WHEN** user enters more than 50 values in reverse mode
+- **THEN** the page SHALL display an error message "反向查詢上限 50 筆"
+- **THEN** the query SHALL NOT be sent
+
+### Requirement: Material Trace page SHALL provide workcenter group filter
+The page SHALL allow filtering results by workcenter group.
+
+#### Scenario: Workcenter group options
+- **WHEN** the page loads
+- **THEN** workcenter group filter SHALL be populated from `filter_cache.get_workcenter_groups()`
+- **THEN** the filter SHALL support multi-select
+- **THEN** default SHALL be "全部站點" (no filter)
+
+#### Scenario: Filter applied to query
+- **WHEN** user selects workcenter groups and clicks "查詢"
+- **THEN** the selected groups SHALL be sent as `workcenter_groups` parameter to the API
+- **THEN** results SHALL only contain records from workcenters in the selected groups
+
+### Requirement: Material Trace page SHALL display query results in a paginated table
+The page SHALL display results in a sortable, paginated detail table.
+
+#### Scenario: Result table columns
+- **WHEN** query results are loaded
+- **THEN** the table SHALL display: LOT ID (CONTAINERNAME), 工單 (PJ_WORKORDER), 站群組 (WORKCENTER_GROUP), 站點 (WORKCENTERNAME), 料號 (MATERIALPARTNAME), 物料批號 (MATERIALLOTNAME), 供應商批號 (VENDORLOTNUMBER), 應領量 (QTYREQUIRED), 實際消耗 (QTYCONSUMED), 機台 (EQUIPMENTNAME), 交易日期 (TXNDATE), 主分類 (PRIMARY_CATEGORY), 副分類 (SECONDARY_CATEGORY)
+
+#### Scenario: Pagination controls
+- **WHEN** results exceed per-page size
+- **THEN** pagination controls SHALL display "上一頁" / "下一頁" buttons and page info in Chinese
+- **THEN** default per-page size SHALL be 50
+
+#### Scenario: Empty results
+- **WHEN** query returns no matching records
+- **THEN** the table area SHALL display "查無資料" message
+
+#### Scenario: Unresolved LOT IDs warning
+- **WHEN** the API response contains `meta.unresolved` array
+- **THEN** a warning banner SHALL display listing the unresolvable LOT names
+
+#### Scenario: Result truncation warning
+- **WHEN** the API response contains `meta.truncated: true`
+- **THEN** an amber warning banner SHALL display "查詢結果超過 10,000 筆上限，請縮小查詢範圍"
+
+### Requirement: Material Trace page SHALL support CSV export
+The page SHALL allow exporting current query results to CSV.
+
+#### Scenario: Export button
+- **WHEN** query results are loaded
+- **THEN** an "匯出 CSV" button SHALL be visible
+- **WHEN** user clicks "匯出 CSV"
+- **THEN** the export request SHALL use the same query parameters as the current query
+
+#### Scenario: Export disabled without results
+- **WHEN** no query has been executed or results are empty
+- **THEN** the "匯出 CSV" button SHALL be disabled
+
+### Requirement: Material Trace page SHALL provide loading and error states
+The page SHALL provide clear feedback during loading and error conditions.
+
+#### Scenario: Loading state
+- **WHEN** a query is in progress
+- **THEN** a loading indicator SHALL be visible
+- **THEN** the query button SHALL be disabled
+
+#### Scenario: API error
+- **WHEN** the API returns an error
+- **THEN** a red error banner SHALL display the error message
+
+#### Scenario: Error cleared on new query
+- **WHEN** user initiates a new query
+- **THEN** previous error and warning banners SHALL be cleared
+
+### Requirement: Material Trace page SHALL use Chinese labels
+The page SHALL display all UI text in Traditional Chinese consistent with the rest of the application.
+
+#### Scenario: Page title
+- **WHEN** the page is rendered
+- **THEN** the page title SHALL be "原物料追溯查詢"
+
+#### Scenario: Button labels
+- **WHEN** the page is rendered
+- **THEN** the query button SHALL display "查詢"
+- **THEN** the export button SHALL display "匯出 CSV"
+- **THEN** the clear button SHALL display "清除"
diff --git a/src/mes_dashboard/app.py b/src/mes_dashboard/app.py
index 1a19406..404c1ca 100644
--- a/src/mes_dashboard/app.py
+++ b/src/mes_dashboard/app.py
@@ -931,6 +931,27 @@ def create_app(config_name: str | None = None) -> Flask:
             200,
         ))
 
+    @app.route('/material-trace')
+    def material_trace_page():
+        """Material trace query page served as pure Vite HTML output."""
+        canonical_redirect = maybe_redirect_to_canonical_shell('/material-trace')
+        if canonical_redirect is not None:
+            return canonical_redirect
+
+        dist_dir = os.path.join(app.static_folder or "", "dist")
+        dist_html = os.path.join(dist_dir, "material-trace.html")
+        if os.path.exists(dist_html):
+            return send_from_directory(dist_dir, 'material-trace.html')
+
+        return missing_in_scope_asset_response('/material-trace', (
+            "<!doctype html><html lang=\"zh-Hant\"><head><meta charset=\"UTF-8\">"
+            "<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">"
+            "<title>原物料追溯查詢</title>"
+            "<script type=\"module\" src=\"/static/dist/material-trace.js\"></script>"
+            "</head><body><div id='app'></div></body></html>",
+            200,
+        ))
+
     # ========================================================
     # Table Query APIs (for table_data_viewer)
     # ========================================================
diff --git a/src/mes_dashboard/routes/__init__.py b/src/mes_dashboard/routes/__init__.py
index d43f307..b534c9b 100644
--- a/src/mes_dashboard/routes/__init__.py
+++ b/src/mes_dashboard/routes/__init__.py
@@ -20,6 +20,7 @@ from .qc_gate_routes import qc_gate_bp
 from .mid_section_defect_routes import mid_section_defect_bp
 from .trace_routes import trace_bp
 from .reject_history_routes import reject_history_bp
+from .material_trace_routes import material_trace_bp
 
 
 def register_routes(app) -> None:
@@ -38,6 +39,7 @@ def register_routes(app) -> None:
     app.register_blueprint(mid_section_defect_bp)
     app.register_blueprint(trace_bp)
     app.register_blueprint(reject_history_bp)
+    app.register_blueprint(material_trace_bp)
 
 __all__ = [
     'wip_bp',
@@ -56,5 +58,6 @@ __all__ = [
     'mid_section_defect_bp',
     'trace_bp',
     'reject_history_bp',
+    'material_trace_bp',
     'register_routes',
 ]
diff --git a/src/mes_dashboard/routes/material_trace_routes.py b/src/mes_dashboard/routes/material_trace_routes.py
new file mode 100644
index 0000000..da1f159
--- /dev/null
+++ b/src/mes_dashboard/routes/material_trace_routes.py
@@ -0,0 +1,185 @@
+# -*- coding: utf-8 -*-
+"""Material trace API routes."""
+
+from __future__ import annotations
+
+import logging
+
+from flask import Blueprint, Response, jsonify
+
+from mes_dashboard.core.rate_limit import configured_rate_limit
+from mes_dashboard.core.request_validation import parse_json_payload
+from mes_dashboard.services.container_resolution_policy import (
+    validate_resolution_request,
+)
+from mes_dashboard.services.filter_cache import get_workcenter_groups
+from mes_dashboard.services.material_trace_service import (
+    export_csv,
+    forward_query,
+    reverse_query,
+)
+
+logger = logging.getLogger("mes_dashboard.material_trace")
+
+material_trace_bp = Blueprint("material_trace", __name__)
+
+# ============================================================
+# Constants
+# ============================================================
+
+_VALID_MODES = {"lot", "workorder", "material_lot"}
+_FORWARD_MODES = {"lot", "workorder"}
+_FORWARD_INPUT_LIMIT = 200
+_REVERSE_INPUT_LIMIT = 50
+_MAX_PER_PAGE = 200
+
+# ============================================================
+# Rate Limiting
+# ============================================================
+
+_QUERY_RATE_LIMIT = configured_rate_limit(
+    bucket="material-trace-query",
+    max_attempts_env="MATERIAL_TRACE_QUERY_RATE_LIMIT_MAX_REQUESTS",
+    window_seconds_env="MATERIAL_TRACE_QUERY_RATE_LIMIT_WINDOW_SECONDS",
+    default_max_attempts=30,
+    default_window_seconds=60,
+)
+
+_EXPORT_RATE_LIMIT = configured_rate_limit(
+    bucket="material-trace-export",
+    max_attempts_env="MATERIAL_TRACE_EXPORT_RATE_LIMIT_MAX_REQUESTS",
+    window_seconds_env="MATERIAL_TRACE_EXPORT_RATE_LIMIT_WINDOW_SECONDS",
+    default_max_attempts=10,
+    default_window_seconds=60,
+)
+
+# ============================================================
+# Helpers
+# ============================================================
+
+
+def _validate_query_params(body: dict) -> tuple[str | None, str, list[str], list[str] | None, int, int]:
+    """Validate and extract query parameters.
+
+    Returns:
+        (error_message, mode, values, workcenter_groups, page, per_page)
+    """
+    mode = str(body.get("mode", "")).strip()
+    if mode not in _VALID_MODES:
+        return f"無效的查詢模式，可用值: {', '.join(sorted(_VALID_MODES))}", "", [], None, 1, 50
+
+    raw_values = body.get("values")
+    if not isinstance(raw_values, list):
+        return "values 必須為陣列", mode, [], None, 1, 50
+
+    values = [str(v).strip() for v in raw_values if str(v).strip()]
+    if not values:
+        return "請輸入至少一筆查詢條件", mode, [], None, 1, 50
+
+    # Input count limits
+    if mode in _FORWARD_MODES and len(values) > _FORWARD_INPUT_LIMIT:
+        return f"正向查詢上限 {_FORWARD_INPUT_LIMIT} 筆", mode, values, None, 1, 50
+    if mode == "material_lot" and len(values) > _REVERSE_INPUT_LIMIT:
+        return f"反向查詢上限 {_REVERSE_INPUT_LIMIT} 筆", mode, values, None, 1, 50
+
+    # Wildcard prefix safety (reuse container_resolution_policy guardrails)
+    _INPUT_TYPE_LABELS = {"lot": "LOT ID", "workorder": "工單", "material_lot": "原物料批號"}
+    wildcard_error = validate_resolution_request(_INPUT_TYPE_LABELS.get(mode, mode), values)
+    if wildcard_error:
+        return wildcard_error, mode, values, None, 1, 50
+
+    # Optional workcenter groups
+    raw_groups = body.get("workcenter_groups")
+    workcenter_groups = None
+    if isinstance(raw_groups, list) and raw_groups:
+        workcenter_groups = [str(g).strip() for g in raw_groups if str(g).strip()]
+        if not workcenter_groups:
+            workcenter_groups = None
+
+    page = max(1, int(body.get("page", 1) or 1))
+    per_page = min(max(1, int(body.get("per_page", 50) or 50)), _MAX_PER_PAGE)
+
+    return None, mode, values, workcenter_groups, page, per_page
+
+
+# ============================================================
+# Routes
+# ============================================================
+
+
+@material_trace_bp.route("/api/material-trace/query", methods=["POST"])
+@_QUERY_RATE_LIMIT
+def api_material_trace_query():
+    """Execute material trace query (forward or reverse)."""
+    body, payload_error = parse_json_payload(require_non_empty_object=True)
+    if payload_error is not None:
+        return jsonify({"success": False, "error": payload_error.message}), payload_error.status_code
+
+    error, mode, values, workcenter_groups, page, per_page = _validate_query_params(body)
+    if error:
+        return jsonify({"success": False, "error": error}), 400
+
+    try:
+        if mode in _FORWARD_MODES:
+            result = forward_query(mode, values, workcenter_groups, page, per_page)
+        else:
+            result = reverse_query(values, workcenter_groups, page, per_page)
+
+        return jsonify({"success": True, **result})
+
+    except MemoryError as exc:
+        logger.warning("Material trace query memory guard: %s", exc)
+        return jsonify({"success": False, "error": str(exc)}), 400
+    except Exception:
+        logger.exception("Material trace query failed: mode=%s", mode)
+        return jsonify({"success": False, "error": "查詢失敗，請稍後再試"}), 500
+
+
+@material_trace_bp.route("/api/material-trace/export", methods=["POST"])
+@_EXPORT_RATE_LIMIT
+def api_material_trace_export():
+    """Export material trace query results as CSV."""
+    body, payload_error = parse_json_payload(require_non_empty_object=True)
+    if payload_error is not None:
+        return jsonify({"success": False, "error": payload_error.message}), payload_error.status_code
+
+    error, mode, values, workcenter_groups, _page, _per_page = _validate_query_params(body)
+    if error:
+        return jsonify({"success": False, "error": error}), 400
+
+    try:
+        csv_bytes, meta = export_csv(mode, values, workcenter_groups)
+
+        response = Response(
+            csv_bytes,
+            mimetype="text/csv; charset=utf-8",
+            headers={
+                "Content-Disposition": "attachment; filename=material_trace.csv",
+            },
+        )
+        if meta.get("truncated"):
+            response.headers["X-Truncated"] = "true"
+            response.headers["X-Max-Rows"] = str(meta.get("export_max_rows", ""))
+        return response
+
+    except MemoryError as exc:
+        logger.warning("Material trace export memory guard: %s", exc)
+        return jsonify({"success": False, "error": str(exc)}), 400
+    except Exception:
+        logger.exception("Material trace export failed: mode=%s", mode)
+        return jsonify({"success": False, "error": "匯出失敗，請稍後再試"}), 500
+
+
+@material_trace_bp.route("/api/material-trace/filter-options", methods=["GET"])
+def api_material_trace_filter_options():
+    """Return workcenter group options for filter dropdown."""
+    groups = get_workcenter_groups()
+    if groups is None:
+        return jsonify({"success": False, "error": "站群組資料載入中"}), 503
+
+    return jsonify({
+        "success": True,
+        "data": {
+            "workcenter_groups": [g["name"] for g in groups],
+        },
+    })
diff --git a/src/mes_dashboard/services/material_trace_service.py b/src/mes_dashboard/services/material_trace_service.py
new file mode 100644
index 0000000..9dd16c1
--- /dev/null
+++ b/src/mes_dashboard/services/material_trace_service.py
@@ -0,0 +1,366 @@
+# -*- coding: utf-8 -*-
+"""Material trace service — bidirectional LOT/material query."""
+
+from __future__ import annotations
+
+import io
+import logging
+import os
+from typing import Any, Dict, List, Optional
+
+import pandas as pd
+
+from mes_dashboard.core.database import read_sql_df, read_sql_df_slow
+from mes_dashboard.services.container_resolution_policy import (
+    validate_resolution_request,
+)
+from mes_dashboard.services.filter_cache import (
+    get_workcenter_mapping,
+    get_workcenters_for_groups,
+)
+from mes_dashboard.sql import QueryBuilder, SQLLoader
+
+logger = logging.getLogger("mes_dashboard.material_trace")
+
+_REVERSE_MAX_ROWS = 10_000
+_EXPORT_MAX_ROWS = 50_000
+
+# Safeguard: max DataFrame memory (MB) before aborting — same pattern as batch_query_engine
+_MAX_RESULT_MB = int(os.getenv("MATERIAL_TRACE_MAX_RESULT_MB", "256"))
+
+# Safeguard: IN-clause batch size — Oracle has practical limits on large IN lists
+_IN_BATCH_SIZE = 1000
+
+_CSV_COLUMNS = {
+    "CONTAINERNAME": "LOT ID",
+    "PJ_WORKORDER": "工單",
+    "WORKCENTER_GROUP": "站群組",
+    "WORKCENTERNAME": "站點",
+    "MATERIALPARTNAME": "料號",
+    "MATERIALLOTNAME": "物料批號",
+    "VENDORLOTNUMBER": "供應商批號",
+    "QTYREQUIRED": "應領量",
+    "QTYCONSUMED": "實際消耗",
+    "EQUIPMENTNAME": "機台",
+    "TXNDATE": "交易日期",
+    "PRIMARY_CATEGORY": "主分類",
+    "SECONDARY_CATEGORY": "副分類",
+}
+
+
+# ============================================================
+# Wildcard helpers (same pattern as query_tool_service)
+# ============================================================
+
+
+def _normalize_wildcard_token(value: str) -> str:
+    """Normalize user wildcard syntax: * → %."""
+    return str(value or "").replace("*", "%")
+
+
+def _is_pattern_token(value: str) -> bool:
+    token = _normalize_wildcard_token(value)
+    return "%" in token or "_" in token
+
+
+def _add_exact_or_pattern_condition(
+    builder: QueryBuilder,
+    column: str,
+    values: List[str],
+) -> None:
+    """Add IN + LIKE mixed condition supporting exact and wildcard tokens.
+
+    Replicates the proven pattern from query_tool_service.
+    """
+    if not values:
+        return
+
+    col_expr = f"NVL({column}, '')"
+    conditions: List[str] = []
+
+    exact_tokens = [v for v in values if not _is_pattern_token(v)]
+    pattern_tokens = [v for v in values if _is_pattern_token(v)]
+
+    if exact_tokens:
+        placeholders: List[str] = []
+        for token in exact_tokens:
+            param = builder._next_param()
+            placeholders.append(f":{param}")
+            builder.params[param] = token
+        conditions.append(f"{col_expr} IN ({', '.join(placeholders)})")
+
+    for token in pattern_tokens:
+        param = builder._next_param()
+        builder.params[param] = _normalize_wildcard_token(token)
+        conditions.append(f"{col_expr} LIKE :{param} ESCAPE '\\'")
+
+    if conditions:
+        builder.add_condition(f"({' OR '.join(conditions)})")
+
+
+# ============================================================
+# Shared helpers
+# ============================================================
+
+
+def _enrich_workcenter_group(df: pd.DataFrame) -> pd.DataFrame:
+    """Add WORKCENTER_GROUP column based on filter_cache mapping."""
+    df = df.copy()
+    mapping = get_workcenter_mapping()
+    if mapping and "WORKCENTERNAME" in df.columns:
+        df["WORKCENTER_GROUP"] = df["WORKCENTERNAME"].map(
+            lambda wc: (mapping.get(wc) or {}).get("group", "")
+        )
+    else:
+        df["WORKCENTER_GROUP"] = ""
+    return df
+
+
+def _resolve_workcenter_names(workcenter_groups: Optional[List[str]]) -> Optional[List[str]]:
+    """Resolve group names to a flat list of WORKCENTERNAME values."""
+    if not workcenter_groups:
+        return None
+    names = get_workcenters_for_groups(workcenter_groups)
+    return names or None
+
+
+def _resolve_container_ids(
+    lot_names: List[str],
+) -> tuple[List[str], Dict[str, str], List[str]]:
+    """Batch-resolve CONTAINERNAME → CONTAINERID (supports wildcards).
+
+    Returns:
+        (container_ids, name_to_id_map, unresolved_names)
+        Note: wildcard tokens are never reported as "unresolved".
+    """
+    builder = QueryBuilder(base_sql=SQLLoader.load("material_trace/resolve_container_ids"))
+    _add_exact_or_pattern_condition(builder, "c.CONTAINERNAME", lot_names)
+    sql, params = builder.build()
+
+    df = read_sql_df(sql, params)
+    if df is None or df.empty:
+        # Only exact tokens can be "unresolved"
+        exact_unresolved = [n for n in lot_names if not _is_pattern_token(n)]
+        return [], {}, exact_unresolved
+
+    name_to_id: Dict[str, str] = {}
+    for _, row in df.iterrows():
+        name_to_id[str(row["CONTAINERNAME"])] = str(row["CONTAINERID"])
+
+    resolved_ids = list(name_to_id.values())
+    # Only report unresolved for exact tokens (wildcards can match 0 rows legitimately)
+    unresolved = [n for n in lot_names if not _is_pattern_token(n) and n not in name_to_id]
+    return resolved_ids, name_to_id, unresolved
+
+
+def _check_memory_guard(df: pd.DataFrame) -> None:
+    """Raise if DataFrame exceeds memory threshold."""
+    mem_mb = df.memory_usage(deep=True).sum() / (1024 * 1024)
+    if mem_mb > _MAX_RESULT_MB:
+        raise MemoryError(
+            f"查詢結果佔用 {mem_mb:.0f} MB，超過 {_MAX_RESULT_MB} MB 上限，請縮小查詢範圍"
+        )
+
+
+def _execute_batched_query(
+    sql_name: str,
+    column: str,
+    values: List[str],
+    wc_names: Optional[List[str]] = None,
+    *,
+    allow_patterns: bool = True,
+) -> pd.DataFrame:
+    """Execute query in batches, using slow-query channel.
+
+    When allow_patterns=True, values containing * or % are sent as LIKE clauses.
+    When allow_patterns=False (e.g. resolved CONTAINERIDs), all values are treated
+    as exact IN matches regardless of content.
+    """
+    base_sql = SQLLoader.load(sql_name)
+    chunks: list[pd.DataFrame] = []
+
+    if allow_patterns:
+        exact_tokens = [v for v in values if not _is_pattern_token(v)]
+        pattern_tokens = [v for v in values if _is_pattern_token(v)]
+    else:
+        exact_tokens = list(values)
+        pattern_tokens = []
+
+    # Batch exact tokens; include pattern tokens once in the first batch
+    for i in range(0, max(len(exact_tokens), 1), _IN_BATCH_SIZE):
+        batch = exact_tokens[i : i + _IN_BATCH_SIZE]
+        combined = batch + (pattern_tokens if i == 0 else [])
+        if not combined:
+            continue
+
+        builder = QueryBuilder(base_sql=base_sql)
+        _add_exact_or_pattern_condition(builder, column, combined)
+        if wc_names:
+            builder.add_in_condition("m.WORKCENTERNAME", wc_names)
+
+        sql, params = builder.build()
+        df = read_sql_df_slow(sql, params)
+        if df is not None and not df.empty:
+            chunks.append(df)
+
+    if not chunks:
+        return pd.DataFrame()
+
+    result = pd.concat(chunks, ignore_index=True) if len(chunks) > 1 else chunks[0]
+    # Deduplicate — wildcards across batches may produce overlapping rows
+    if len(chunks) > 1 and "CONTAINERID" in result.columns:
+        result = result.drop_duplicates(subset=["CONTAINERID", "MATERIALLOTNAME", "WORKCENTERNAME", "TXNDATE"], ignore_index=True)
+    _check_memory_guard(result)
+    return result
+
+
+def _paginate(df: pd.DataFrame, page: int, per_page: int) -> Dict[str, Any]:
+    """Apply pagination to a DataFrame and return paginated dict."""
+    total = len(df)
+    total_pages = max(1, (total + per_page - 1) // per_page)
+    page = min(page, total_pages)
+    start = (page - 1) * per_page
+    end = start + per_page
+    page_df = df.iloc[start:end]
+
+    # Replace NaN/NaT with None so JSON serialization produces null (not NaN).
+    # Must convert to object dtype first — float64 columns coerce None back to NaN.
+    page_df = page_df.astype(object).where(page_df.notna(), None)
+
+    return {
+        "rows": page_df.to_dict("records"),
+        "pagination": {
+            "page": page,
+            "per_page": per_page,
+            "total": total,
+            "total_pages": total_pages,
+        },
+    }
+
+
+# ============================================================
+# Forward query (LOT ID / Work Order → Materials)
+# ============================================================
+
+
+def forward_query(
+    mode: str,
+    values: List[str],
+    workcenter_groups: Optional[List[str]] = None,
+    page: int = 1,
+    per_page: int = 50,
+) -> Dict[str, Any]:
+    """Execute forward material trace query."""
+    meta: Dict[str, Any] = {}
+    wc_names = _resolve_workcenter_names(workcenter_groups)
+
+    if mode == "lot":
+        container_ids, _name_map, unresolved = _resolve_container_ids(values)
+        if unresolved:
+            meta["unresolved"] = unresolved
+        if not container_ids:
+            return {"rows": [], "pagination": {"page": 1, "per_page": per_page, "total": 0, "total_pages": 0}, "meta": meta}
+
+        df = _execute_batched_query("material_trace/forward_by_lot", "m.CONTAINERID", container_ids, wc_names, allow_patterns=False)
+
+    else:  # workorder
+        df = _execute_batched_query("material_trace/forward_by_workorder", "m.PJ_WORKORDER", values, wc_names)
+
+    if df.empty:
+        return {"rows": [], "pagination": {"page": 1, "per_page": per_page, "total": 0, "total_pages": 0}, "meta": meta}
+
+    df = _enrich_workcenter_group(df)
+    result = _paginate(df, page, per_page)
+    result["meta"] = meta
+    return result
+
+
+# ============================================================
+# Reverse query (Material Lot → LOTs)
+# ============================================================
+
+
+def reverse_query(
+    values: List[str],
+    workcenter_groups: Optional[List[str]] = None,
+    page: int = 1,
+    per_page: int = 50,
+) -> Dict[str, Any]:
+    """Execute reverse material trace query."""
+    meta: Dict[str, Any] = {}
+    wc_names = _resolve_workcenter_names(workcenter_groups)
+
+    df = _execute_batched_query("material_trace/reverse_by_material_lot", "m.MATERIALLOTNAME", values, wc_names)
+
+    if df.empty:
+        return {"rows": [], "pagination": {"page": 1, "per_page": per_page, "total": 0, "total_pages": 0}, "meta": meta}
+
+    # Check truncation (SQL fetches 10001 rows to detect overflow)
+    if len(df) > _REVERSE_MAX_ROWS:
+        df = df.iloc[:_REVERSE_MAX_ROWS]
+        meta["truncated"] = True
+        meta["max_rows"] = _REVERSE_MAX_ROWS
+
+    df = _enrich_workcenter_group(df)
+    result = _paginate(df, page, per_page)
+    result["meta"] = meta
+    return result
+
+
+# ============================================================
+# CSV Export
+# ============================================================
+
+
+def export_csv(
+    mode: str,
+    values: List[str],
+    workcenter_groups: Optional[List[str]] = None,
+) -> tuple[bytes, Dict[str, Any]]:
+    """Export query results as UTF-8 BOM CSV."""
+    meta: Dict[str, Any] = {}
+    wc_names = _resolve_workcenter_names(workcenter_groups)
+
+    if mode == "lot":
+        container_ids, _name_map, unresolved = _resolve_container_ids(values)
+        if unresolved:
+            meta["unresolved"] = unresolved
+        if not container_ids:
+            return _empty_csv(), meta
+
+        df = _execute_batched_query("material_trace/forward_by_lot", "m.CONTAINERID", container_ids, wc_names, allow_patterns=False)
+
+    elif mode == "workorder":
+        df = _execute_batched_query("material_trace/forward_by_workorder", "m.PJ_WORKORDER", values, wc_names)
+
+    else:  # material_lot
+        df = _execute_batched_query("material_trace/reverse_by_material_lot", "m.MATERIALLOTNAME", values, wc_names)
+
+    if df.empty:
+        return _empty_csv(), meta
+
+    # Truncate if over export limit
+    if len(df) > _EXPORT_MAX_ROWS:
+        df = df.iloc[:_EXPORT_MAX_ROWS]
+        meta["truncated"] = True
+        meta["export_max_rows"] = _EXPORT_MAX_ROWS
+
+    df = _enrich_workcenter_group(df)
+
+    # Select and rename columns for CSV
+    available_cols = [c for c in _CSV_COLUMNS if c in df.columns]
+    export_df = df[available_cols].rename(columns=_CSV_COLUMNS)
+
+    buf = io.BytesIO()
+    buf.write(b"\xef\xbb\xbf")  # UTF-8 BOM
+    buf.write(export_df.fillna("").to_csv(index=False).encode("utf-8"))
+    return buf.getvalue(), meta
+
+
+def _empty_csv() -> bytes:
+    """Return an empty CSV with headers only."""
+    buf = io.BytesIO()
+    buf.write(b"\xef\xbb\xbf")
+    headers = ",".join(_CSV_COLUMNS.values()) + "\n"
+    buf.write(headers.encode("utf-8"))
+    return buf.getvalue()
diff --git a/src/mes_dashboard/sql/material_trace/forward_by_lot.sql b/src/mes_dashboard/sql/material_trace/forward_by_lot.sql
new file mode 100644
index 0000000..cf83fac
--- /dev/null
+++ b/src/mes_dashboard/sql/material_trace/forward_by_lot.sql
@@ -0,0 +1,29 @@
+-- Forward Material Trace by LOT (CONTAINERID)
+-- Retrieves material consumption records for given CONTAINERIDs
+--
+-- Parameters:
+--   Bind variables generated by QueryBuilder.add_in_condition()
+--   for CONTAINERID IN (:p0, :p1, ...)
+--
+-- Template slots:
+--   {{ WHERE_CLAUSE }} - Dynamic WHERE with CONTAINERID IN + optional WORKCENTERNAME IN
+
+SELECT
+    m.CONTAINERID,
+    c.CONTAINERNAME,
+    m.PJ_WORKORDER,
+    m.WORKCENTERNAME,
+    m.MATERIALPARTNAME,
+    m.MATERIALLOTNAME,
+    m.VENDORLOTNUMBER,
+    m.QTYREQUIRED,
+    m.QTYCONSUMED,
+    m.EQUIPMENTNAME,
+    m.TXNDATE,
+    m.PRIMARY_CATEGORY,
+    m.SECONDARY_CATEGORY
+FROM DWH.DW_MES_LOTMATERIALSHISTORY m
+LEFT JOIN DWH.DW_MES_CONTAINER c
+    ON c.CONTAINERID = m.CONTAINERID
+{{ WHERE_CLAUSE }}
+ORDER BY m.TXNDATE DESC
diff --git a/src/mes_dashboard/sql/material_trace/forward_by_workorder.sql b/src/mes_dashboard/sql/material_trace/forward_by_workorder.sql
new file mode 100644
index 0000000..a6ac2ed
--- /dev/null
+++ b/src/mes_dashboard/sql/material_trace/forward_by_workorder.sql
@@ -0,0 +1,29 @@
+-- Forward Material Trace by Work Order (PJ_WORKORDER)
+-- Retrieves material consumption records for given work orders
+--
+-- Parameters:
+--   Bind variables generated by QueryBuilder.add_in_condition()
+--   for PJ_WORKORDER IN (:p0, :p1, ...)
+--
+-- Template slots:
+--   {{ WHERE_CLAUSE }} - Dynamic WHERE with PJ_WORKORDER IN + optional WORKCENTERNAME IN
+
+SELECT
+    m.CONTAINERID,
+    c.CONTAINERNAME,
+    m.PJ_WORKORDER,
+    m.WORKCENTERNAME,
+    m.MATERIALPARTNAME,
+    m.MATERIALLOTNAME,
+    m.VENDORLOTNUMBER,
+    m.QTYREQUIRED,
+    m.QTYCONSUMED,
+    m.EQUIPMENTNAME,
+    m.TXNDATE,
+    m.PRIMARY_CATEGORY,
+    m.SECONDARY_CATEGORY
+FROM DWH.DW_MES_LOTMATERIALSHISTORY m
+LEFT JOIN DWH.DW_MES_CONTAINER c
+    ON c.CONTAINERID = m.CONTAINERID
+{{ WHERE_CLAUSE }}
+ORDER BY m.TXNDATE DESC
diff --git a/src/mes_dashboard/sql/material_trace/resolve_container_ids.sql b/src/mes_dashboard/sql/material_trace/resolve_container_ids.sql
new file mode 100644
index 0000000..c9cea8c
--- /dev/null
+++ b/src/mes_dashboard/sql/material_trace/resolve_container_ids.sql
@@ -0,0 +1,12 @@
+-- Resolve CONTAINERNAME to CONTAINERID
+-- Batch lookup for LOT ID -> CONTAINERID conversion
+--
+-- Parameters:
+--   Bind variables generated by QueryBuilder.add_in_condition()
+--   for CONTAINERNAME IN (:p0, :p1, ...)
+
+SELECT
+    c.CONTAINERID,
+    c.CONTAINERNAME
+FROM DWH.DW_MES_CONTAINER c
+{{ WHERE_CLAUSE }}
diff --git a/src/mes_dashboard/sql/material_trace/reverse_by_material_lot.sql b/src/mes_dashboard/sql/material_trace/reverse_by_material_lot.sql
new file mode 100644
index 0000000..66ee76f
--- /dev/null
+++ b/src/mes_dashboard/sql/material_trace/reverse_by_material_lot.sql
@@ -0,0 +1,32 @@
+-- Reverse Material Trace by Material Lot Name (MATERIALLOTNAME)
+-- Retrieves LOTs that consumed given material lot names
+--
+-- Parameters:
+--   Bind variables generated by QueryBuilder.add_in_condition()
+--   for MATERIALLOTNAME IN (:p0, :p1, ...)
+--
+-- Template slots:
+--   {{ WHERE_CLAUSE }} - Dynamic WHERE with MATERIALLOTNAME IN + optional WORKCENTERNAME IN
+--
+-- Note: FETCH FIRST 10001 ROWS ONLY to detect truncation (> 10000)
+
+SELECT
+    m.CONTAINERID,
+    c.CONTAINERNAME,
+    m.PJ_WORKORDER,
+    m.WORKCENTERNAME,
+    m.MATERIALPARTNAME,
+    m.MATERIALLOTNAME,
+    m.VENDORLOTNUMBER,
+    m.QTYREQUIRED,
+    m.QTYCONSUMED,
+    m.EQUIPMENTNAME,
+    m.TXNDATE,
+    m.PRIMARY_CATEGORY,
+    m.SECONDARY_CATEGORY
+FROM DWH.DW_MES_LOTMATERIALSHISTORY m
+LEFT JOIN DWH.DW_MES_CONTAINER c
+    ON c.CONTAINERID = m.CONTAINERID
+{{ WHERE_CLAUSE }}
+ORDER BY m.TXNDATE DESC
+FETCH FIRST 10001 ROWS ONLY
diff --git a/tests/test_material_trace_routes.py b/tests/test_material_trace_routes.py
new file mode 100644
index 0000000..bfe4a08
--- /dev/null
+++ b/tests/test_material_trace_routes.py
@@ -0,0 +1,276 @@
+# -*- coding: utf-8 -*-
+"""Integration tests for Material Trace API routes.
+
+Tests input validation, pagination structure, and CSV export.
+"""
+
+import json
+import pytest
+from unittest.mock import patch, MagicMock
+
+from mes_dashboard import create_app
+from mes_dashboard.core.cache import NoOpCache
+from mes_dashboard.core.rate_limit import reset_rate_limits_for_tests
+
+
+@pytest.fixture
+def app():
+    """Create test Flask application."""
+    app = create_app()
+    app.config["TESTING"] = True
+    app.extensions["cache"] = NoOpCache()
+    return app
+
+
+@pytest.fixture
+def client(app):
+    """Create test client."""
+    return app.test_client()
+
+
+@pytest.fixture(autouse=True)
+def _reset_rate_limits():
+    reset_rate_limits_for_tests()
+    yield
+    reset_rate_limits_for_tests()
+
+
+# ============================================================
+# 7.6 Input validation → HTTP 400
+# ============================================================
+
+
+class TestQueryValidation:
+    def test_missing_mode_returns_400(self, client):
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"values": ["LOT-A"]}),
+            content_type="application/json",
+        )
+        assert response.status_code == 400
+        payload = response.get_json()
+        assert payload["success"] is False
+        assert "無效的查詢模式" in payload["error"]
+
+    def test_invalid_mode_returns_400(self, client):
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"mode": "invalid", "values": ["LOT-A"]}),
+            content_type="application/json",
+        )
+        assert response.status_code == 400
+        assert "無效的查詢模式" in response.get_json()["error"]
+
+    def test_empty_values_returns_400(self, client):
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"mode": "lot", "values": []}),
+            content_type="application/json",
+        )
+        assert response.status_code == 400
+        assert "請輸入至少一筆" in response.get_json()["error"]
+
+    def test_blank_values_returns_400(self, client):
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"mode": "lot", "values": ["", "  "]}),
+            content_type="application/json",
+        )
+        assert response.status_code == 400
+        assert "請輸入至少一筆" in response.get_json()["error"]
+
+    def test_forward_over_200_returns_400(self, client):
+        values = [f"LOT-{i}" for i in range(201)]
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"mode": "lot", "values": values}),
+            content_type="application/json",
+        )
+        assert response.status_code == 400
+        assert "正向查詢上限 200 筆" in response.get_json()["error"]
+
+    def test_workorder_over_200_returns_400(self, client):
+        values = [f"WO-{i}" for i in range(201)]
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"mode": "workorder", "values": values}),
+            content_type="application/json",
+        )
+        assert response.status_code == 400
+        assert "正向查詢上限 200 筆" in response.get_json()["error"]
+
+    def test_reverse_over_50_returns_400(self, client):
+        values = [f"MLOT-{i}" for i in range(51)]
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"mode": "material_lot", "values": values}),
+            content_type="application/json",
+        )
+        assert response.status_code == 400
+        assert "反向查詢上限 50 筆" in response.get_json()["error"]
+
+    def test_non_json_returns_415(self, client):
+        response = client.post(
+            "/api/material-trace/query",
+            data="plain text",
+            content_type="text/plain",
+        )
+        assert response.status_code == 415
+
+    def test_empty_body_returns_400(self, client):
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({}),
+            content_type="application/json",
+        )
+        # Empty object triggers require_non_empty_object
+        assert response.status_code in (400, 415)
+
+
+# ============================================================
+# 7.7 Query endpoint — correct pagination structure
+# ============================================================
+
+
+class TestQueryPagination:
+    @patch("mes_dashboard.routes.material_trace_routes.forward_query")
+    def test_query_returns_pagination_structure(self, mock_fwd, client):
+        mock_fwd.return_value = {
+            "rows": [{"CONTAINERNAME": "LOT-1", "PJ_WORKORDER": "WO-1"}],
+            "pagination": {
+                "page": 1,
+                "per_page": 50,
+                "total": 100,
+                "total_pages": 2,
+            },
+            "meta": {},
+        }
+
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"mode": "workorder", "values": ["WO-001"]}),
+            content_type="application/json",
+        )
+
+        assert response.status_code == 200
+        payload = response.get_json()
+        assert payload["success"] is True
+        assert "pagination" in payload
+        pag = payload["pagination"]
+        assert pag["page"] == 1
+        assert pag["per_page"] == 50
+        assert pag["total"] == 100
+        assert pag["total_pages"] == 2
+        assert len(payload["rows"]) == 1
+
+    @patch("mes_dashboard.routes.material_trace_routes.forward_query")
+    def test_query_passes_page_param(self, mock_fwd, client):
+        mock_fwd.return_value = {
+            "rows": [],
+            "pagination": {"page": 3, "per_page": 50, "total": 200, "total_pages": 4},
+            "meta": {},
+        }
+
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"mode": "workorder", "values": ["WO-001"], "page": 3}),
+            content_type="application/json",
+        )
+
+        assert response.status_code == 200
+        mock_fwd.assert_called_once()
+        call_kwargs = mock_fwd.call_args
+        # page should be 3
+        assert call_kwargs[0][3] == 3 or call_kwargs.kwargs.get("page") == 3
+
+    @patch("mes_dashboard.routes.material_trace_routes.reverse_query")
+    def test_reverse_mode_dispatches_correctly(self, mock_rev, client):
+        mock_rev.return_value = {
+            "rows": [],
+            "pagination": {"page": 1, "per_page": 50, "total": 0, "total_pages": 0},
+            "meta": {},
+        }
+
+        response = client.post(
+            "/api/material-trace/query",
+            data=json.dumps({"mode": "material_lot", "values": ["MLOT-A"]}),
+            content_type="application/json",
+        )
+
+        assert response.status_code == 200
+        mock_rev.assert_called_once()
+
+
+# ============================================================
+# 7.8 Export endpoint — CSV content-type and UTF-8 BOM
+# ============================================================
+
+
+class TestExportEndpoint:
+    @patch("mes_dashboard.routes.material_trace_routes.export_csv")
+    def test_export_returns_csv_content_type(self, mock_export, client):
+        csv_content = b"\xef\xbb\xbfLOT ID,\xe5\xb7\xa5\xe5\x96\xae\n"
+        mock_export.return_value = (csv_content, {})
+
+        response = client.post(
+            "/api/material-trace/export",
+            data=json.dumps({"mode": "workorder", "values": ["WO-001"]}),
+            content_type="application/json",
+        )
+
+        assert response.status_code == 200
+        assert "text/csv" in response.content_type
+        # Check UTF-8 BOM
+        assert response.data[:3] == b"\xef\xbb\xbf"
+
+    @patch("mes_dashboard.routes.material_trace_routes.export_csv")
+    def test_export_truncated_sets_header(self, mock_export, client):
+        csv_content = b"\xef\xbb\xbfheader\nrow\n"
+        mock_export.return_value = (csv_content, {"truncated": True, "export_max_rows": 50000})
+
+        response = client.post(
+            "/api/material-trace/export",
+            data=json.dumps({"mode": "workorder", "values": ["WO-001"]}),
+            content_type="application/json",
+        )
+
+        assert response.status_code == 200
+        assert response.headers.get("X-Truncated") == "true"
+
+    def test_export_validation_same_as_query(self, client):
+        """Export should reject invalid mode same as query."""
+        response = client.post(
+            "/api/material-trace/export",
+            data=json.dumps({"mode": "invalid", "values": ["X"]}),
+            content_type="application/json",
+        )
+        assert response.status_code == 400
+
+
+# ============================================================
+# Filter options endpoint
+# ============================================================
+
+
+class TestFilterOptions:
+    @patch("mes_dashboard.routes.material_trace_routes.get_workcenter_groups")
+    def test_filter_options_returns_groups(self, mock_groups, client):
+        mock_groups.return_value = [
+            {"name": "焊接_DB", "sequence": 1},
+            {"name": "焊線_WB", "sequence": 2},
+        ]
+
+        response = client.get("/api/material-trace/filter-options")
+
+        assert response.status_code == 200
+        payload = response.get_json()
+        assert payload["success"] is True
+        assert payload["data"]["workcenter_groups"] == ["焊接_DB", "焊線_WB"]
+
+    @patch("mes_dashboard.routes.material_trace_routes.get_workcenter_groups")
+    def test_filter_options_unavailable_returns_503(self, mock_groups, client):
+        mock_groups.return_value = None
+
+        response = client.get("/api/material-trace/filter-options")
+
+        assert response.status_code == 503
diff --git a/tests/test_material_trace_service.py b/tests/test_material_trace_service.py
new file mode 100644
index 0000000..1ddd0c7
--- /dev/null
+++ b/tests/test_material_trace_service.py
@@ -0,0 +1,350 @@
+# -*- coding: utf-8 -*-
+"""Unit tests for material_trace_service.
+
+Tests cover forward/reverse query logic, CONTAINERID resolution,
+workcenter group enrichment/filtering, truncation, CSV export,
+safeguards (memory guard, batched queries), and wildcard support.
+"""
+
+import pytest
+from unittest.mock import patch, MagicMock, call
+
+import pandas as pd
+
+from mes_dashboard.services.material_trace_service import (
+    _add_exact_or_pattern_condition,
+    _enrich_workcenter_group,
+    _is_pattern_token,
+    _resolve_container_ids,
+    _resolve_workcenter_names,
+    _check_memory_guard,
+    _IN_BATCH_SIZE,
+    export_csv,
+    forward_query,
+    reverse_query,
+)
+from mes_dashboard.sql import QueryBuilder
+
+
+# ============================================================
+# Fixtures
+# ============================================================
+
+MOCK_WORKCENTER_MAPPING = {
+    "WC_DB_1": {"group": "焊接_DB", "sequence": 1},
+    "WC_DB_2": {"group": "焊接_DB", "sequence": 1},
+    "WC_WB_1": {"group": "焊線_WB", "sequence": 2},
+    "WC_MOLD_1": {"group": "封膠_Mold", "sequence": 3},
+}
+
+
+def _make_material_df(n=3, workcenter="WC_DB_1"):
+    """Create a sample material consumption DataFrame."""
+    return pd.DataFrame(
+        {
+            "CONTAINERID": [f"CID{i:016d}" for i in range(n)],
+            "CONTAINERNAME": [f"LOT-{i:04d}" for i in range(n)],
+            "PJ_WORKORDER": [f"WO-{i}" for i in range(n)],
+            "WORKCENTERNAME": [workcenter] * n,
+            "MATERIALPARTNAME": [f"MAT-{i}" for i in range(n)],
+            "MATERIALLOTNAME": [f"MLOT-{i}" for i in range(n)],
+            "VENDORLOTNUMBER": [f"VL-{i}" for i in range(n)],
+            "QTYREQUIRED": [10.0] * n,
+            "QTYCONSUMED": [9.5] * n,
+            "EQUIPMENTNAME": [f"EQ-{i}" for i in range(n)],
+            "TXNDATE": ["2025-06-01"] * n,
+            "PRIMARY_CATEGORY": ["CAT_A"] * n,
+            "SECONDARY_CATEGORY": ["SUB_1"] * n,
+        }
+    )
+
+
+def _make_resolve_df(lot_names):
+    """Create a DataFrame simulating DW_MES_CONTAINER resolve result."""
+    rows = []
+    for name in lot_names:
+        rows.append({"CONTAINERID": f"CID_{name}", "CONTAINERNAME": name})
+    return pd.DataFrame(rows)
+
+
+# ============================================================
+# 7.1 Forward LOT mode — resolve + enrichment
+# ============================================================
+
+
+class TestForwardLotQuery:
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_forward_lot_resolves_and_enriches(self, mock_mapping, mock_sql, mock_sql_slow):
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        mock_sql.return_value = _make_resolve_df(["LOT-A", "LOT-B"])
+        mock_sql_slow.return_value = _make_material_df(5)
+
+        result = forward_query("lot", ["LOT-A", "LOT-B"], page=1, per_page=50)
+
+        assert result["pagination"]["total"] == 5
+        assert len(result["rows"]) == 5
+        assert result["rows"][0]["WORKCENTER_GROUP"] == "焊接_DB"
+        assert result["meta"] == {}
+        assert mock_sql.call_count == 1
+        assert mock_sql_slow.call_count == 1
+
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_forward_lot_all_unresolved_returns_empty(self, mock_mapping, mock_sql, mock_sql_slow):
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        mock_sql.return_value = pd.DataFrame()
+
+        result = forward_query("lot", ["UNKNOWN-LOT"], page=1, per_page=50)
+
+        assert result["rows"] == []
+        assert result["pagination"]["total"] == 0
+        assert result["meta"]["unresolved"] == ["UNKNOWN-LOT"]
+        mock_sql_slow.assert_not_called()
+
+
+# ============================================================
+# 7.2 Forward work order mode
+# ============================================================
+
+
+class TestForwardWorkorderQuery:
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_forward_workorder_queries_directly(self, mock_mapping, mock_sql_slow):
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        mock_sql_slow.return_value = _make_material_df(3)
+
+        result = forward_query("workorder", ["WO-2025-001"], page=1, per_page=50)
+
+        assert result["pagination"]["total"] == 3
+        assert len(result["rows"]) == 3
+        assert mock_sql_slow.call_count == 1
+
+
+# ============================================================
+# 7.3 Reverse query — truncation logic
+# ============================================================
+
+
+class TestReverseQuery:
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_reverse_truncation_at_10000(self, mock_mapping, mock_sql_slow):
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        mock_sql_slow.return_value = _make_material_df(10001)
+
+        result = reverse_query(["MLOT-A"], page=1, per_page=50)
+
+        assert result["meta"]["truncated"] is True
+        assert result["meta"]["max_rows"] == 10000
+        assert result["pagination"]["total"] == 10000
+
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_reverse_no_truncation_under_limit(self, mock_mapping, mock_sql_slow):
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        mock_sql_slow.return_value = _make_material_df(500)
+
+        result = reverse_query(["MLOT-A"], page=1, per_page=50)
+
+        assert "truncated" not in result["meta"]
+        assert result["pagination"]["total"] == 500
+
+
+# ============================================================
+# 7.4 Workcenter group filtering
+# ============================================================
+
+
+class TestWorkcenterGroupFilter:
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenters_for_groups")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_workcenter_group_resolves_to_names(self, mock_mapping, mock_for_groups, mock_sql_slow):
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        mock_for_groups.return_value = ["WC_DB_1", "WC_DB_2"]
+        mock_sql_slow.return_value = _make_material_df(3)
+
+        result = forward_query(
+            "workorder", ["WO-001"], workcenter_groups=["焊接_DB"], page=1, per_page=50
+        )
+
+        mock_for_groups.assert_called_once_with(["焊接_DB"])
+        sql_call = mock_sql_slow.call_args
+        sql_text = sql_call[0][0]
+        assert "WORKCENTERNAME IN" in sql_text
+        assert result["pagination"]["total"] == 3
+
+
+# ============================================================
+# 7.5 Unresolved LOT IDs
+# ============================================================
+
+
+class TestUnresolvedLots:
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_partial_resolve_reports_unresolved(self, mock_mapping, mock_sql, mock_sql_slow):
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        resolve_df = pd.DataFrame(
+            [{"CONTAINERID": "CID_LOT_A", "CONTAINERNAME": "LOT-A"}]
+        )
+        mock_sql.return_value = resolve_df
+        mock_sql_slow.return_value = _make_material_df(2)
+
+        result = forward_query("lot", ["LOT-A", "LOT-B"], page=1, per_page=50)
+
+        assert result["meta"]["unresolved"] == ["LOT-B"]
+        assert result["pagination"]["total"] == 2
+
+
+# ============================================================
+# Enrichment helper
+# ============================================================
+
+
+class TestEnrichWorkcenterGroup:
+    def test_enrich_maps_correctly(self):
+        df = pd.DataFrame({"WORKCENTERNAME": ["WC_DB_1", "WC_WB_1", "UNKNOWN"]})
+        with patch(
+            "mes_dashboard.services.material_trace_service.get_workcenter_mapping"
+        ) as mock:
+            mock.return_value = MOCK_WORKCENTER_MAPPING
+            result = _enrich_workcenter_group(df)
+
+        assert list(result["WORKCENTER_GROUP"]) == ["焊接_DB", "焊線_WB", ""]
+
+
+# ============================================================
+# CSV export
+# ============================================================
+
+
+class TestExportCsv:
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_export_returns_utf8_bom_csv(self, mock_mapping, mock_sql_slow):
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        mock_sql_slow.return_value = _make_material_df(3)
+
+        csv_bytes, meta = export_csv("workorder", ["WO-001"])
+
+        assert csv_bytes[:3] == b"\xef\xbb\xbf"
+        csv_text = csv_bytes.decode("utf-8-sig")
+        assert "LOT ID" in csv_text
+        assert "料號" in csv_text
+        lines = csv_text.strip().split("\n")
+        assert len(lines) == 4
+
+
+# ============================================================
+# Safeguards: memory guard
+# ============================================================
+
+
+class TestMemoryGuard:
+    def test_memory_guard_raises_on_large_df(self):
+        with patch("mes_dashboard.services.material_trace_service._MAX_RESULT_MB", 0):
+            df = _make_material_df(10)
+            with pytest.raises(MemoryError, match="超過.*上限"):
+                _check_memory_guard(df)
+
+    def test_memory_guard_passes_small_df(self):
+        df = _make_material_df(5)
+        _check_memory_guard(df)
+
+
+# ============================================================
+# Safeguards: IN-clause batching
+# ============================================================
+
+
+class TestInClauseBatching:
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_large_input_is_batched(self, mock_mapping, mock_sql_slow):
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        mock_sql_slow.return_value = _make_material_df(3)
+
+        values = [f"WO-{i}" for i in range(1500)]
+        result = forward_query("workorder", values, page=1, per_page=50)
+
+        assert mock_sql_slow.call_count == 2
+        assert result["pagination"]["total"] > 0
+
+
+# ============================================================
+# Wildcard support
+# ============================================================
+
+
+class TestWildcardHelpers:
+    def test_is_pattern_token_with_star(self):
+        assert _is_pattern_token("GA250605*") is True
+
+    def test_is_pattern_token_with_percent(self):
+        assert _is_pattern_token("GA250605%") is True
+
+    def test_is_pattern_token_exact(self):
+        assert _is_pattern_token("GA25060001-A01") is False
+
+    def test_add_exact_or_pattern_mixed(self):
+        """Mixed exact + wildcard values produce IN + LIKE conditions."""
+        builder = QueryBuilder(base_sql="SELECT 1 FROM t {{ WHERE_CLAUSE }}")
+        _add_exact_or_pattern_condition(builder, "col", ["EXACT-1", "WILD*"])
+        sql, params = builder.build()
+        assert "IN" in sql
+        assert "LIKE" in sql
+        # Wildcard normalized: * → %
+        like_params = [v for v in params.values() if "%" in str(v)]
+        assert len(like_params) == 1
+        assert like_params[0] == "WILD%"
+
+
+class TestWildcardResolve:
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df")
+    def test_wildcard_resolve_generates_like(self, mock_sql):
+        """Wildcard LOT names produce LIKE clause in resolve SQL."""
+        mock_sql.return_value = _make_resolve_df(["LOT-A001"])
+
+        _resolve_container_ids(["LOT-A*"])
+
+        sql_text = mock_sql.call_args[0][0]
+        assert "LIKE" in sql_text
+
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df")
+    def test_wildcard_not_reported_as_unresolved(self, mock_sql):
+        """Wildcard tokens that match 0 rows should NOT appear in unresolved."""
+        mock_sql.return_value = pd.DataFrame()
+
+        _, _, unresolved = _resolve_container_ids(["WILD*"])
+
+        # Wildcard tokens are not counted as unresolved
+        assert unresolved == []
+
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df")
+    def test_exact_unresolved_still_reported(self, mock_sql):
+        """Exact tokens that don't resolve ARE reported as unresolved."""
+        mock_sql.return_value = pd.DataFrame()
+
+        _, _, unresolved = _resolve_container_ids(["EXACT-MISSING"])
+
+        assert unresolved == ["EXACT-MISSING"]
+
+
+class TestWildcardWorkorder:
+    @patch("mes_dashboard.services.material_trace_service.read_sql_df_slow")
+    @patch("mes_dashboard.services.material_trace_service.get_workcenter_mapping")
+    def test_workorder_wildcard_generates_like(self, mock_mapping, mock_sql_slow):
+        """Wildcard work orders produce LIKE clause in query SQL."""
+        mock_mapping.return_value = MOCK_WORKCENTER_MAPPING
+        mock_sql_slow.return_value = _make_material_df(3)
+
+        forward_query("workorder", ["WO-2025*"], page=1, per_page=50)
+
+        sql_text = mock_sql_slow.call_args[0][0]
+        assert "LIKE" in sql_text