diff --git a/src/agentkit/server/frontend/e2e/bitable-record-drawer.spec.ts b/src/agentkit/server/frontend/e2e/bitable-record-drawer.spec.ts
new file mode 100644
index 0000000..cf8faa5
--- /dev/null
+++ b/src/agentkit/server/frontend/e2e/bitable-record-drawer.spec.ts
@@ -0,0 +1,316 @@
+/**
+ * E2E tests for the Bitable record detail drawer (U3 / R2).
+ *
+ * Flow: login → create file → create table → seed a record via API →
+ *       click the row's seq cell → assert drawer opens with all field types.
+ *
+ * ponytail: record + extra-field seeding goes through the REST API (via
+ * page.evaluate fetch) rather than UI clicks — setup is not the thing under
+ * test, and API seeding is ~10x faster + more deterministic than driving the
+ * add-field / add-record UI for 11+ fields. Ceiling: API path couples the
+ * test to the /tables/{id}/fields + /tables/{id}/records contract; if that
+ * contract shifts, setup breaks (acceptable — the same contract is exercised
+ * by the grid itself).
+ *
+ * Requires: running backend with PostgreSQL. Skips gracefully if unreachable.
+ */
+
+import { test, expect, type Page } from '@playwright/test'
+import { TEST_USER, clearAuth, waitForServer, API_BASE } from './helpers'
+
+interface IField {
+  id: string
+  name: string
+  field_type: string
+  owner: string
+}
+
+interface IRecord {
+  id: string
+  values: Record<string, unknown>
+}
+
+// API_BASE is an absolute URL (http://127.0.0.1:PORT/api/v1) — passed into
+// page.evaluate as an arg because the browser context cannot close over
+// Node-scope variables.
+const API_BASE_STR = API_BASE
+
+async function loginAndCreateTable(
+  page: Page,
+  fileName: string,
+  tableName: string,
+): Promise<{ tableId: string; fields: IField[] }> {
+  await page.goto('/login')
+  await clearAuth(page)
+  await page.getByPlaceholder('请输入用户名').fill(TEST_USER.username)
+  await page.getByPlaceholder('请输入密码').fill(TEST_USER.password)
+  await page.getByRole('button', { name: /登\s*录/ }).click()
+  await expect(page).toHaveURL(/\/agent/, { timeout: 15_000 })
+
+  await page.getByRole('button', { name: '多维表格' }).click()
+  await expect(page).toHaveURL(/\/bitable$/, { timeout: 15_000 })
+
+  // Create file
+  await page.getByRole('button', { name: /新建文件/ }).click()
+  await page.getByPlaceholder('请输入文件名').fill(fileName)
+  await page.getByRole('button', { name: /确\s*定/ }).click()
+  await expect(page).toHaveURL(/\/bitable\/[^/]+/, { timeout: 10_000 })
+
+  // Create table
+  await page.locator('.table-view-list__header .ant-btn').click()
+  await page.getByPlaceholder('请输入表名').fill(tableName)
+  await page.getByRole('button', { name: /确\s*定/ }).click()
+  await expect(page.locator('.bitable-file-detail-view__table-name')).toContainText(
+    tableName,
+    { timeout: 10_000 },
+  )
+
+  // Fetch table id + fields via API (auth token is in localStorage after UI login).
+  // apiBase is passed as an arg — browser context cannot close over Node vars.
+  const { tableId, fields } = await page.evaluate(async (apiBase: string) => {
+    const token = localStorage.getItem('agentkit.access_token') ?? ''
+    const tablesResp = await fetch(`${apiBase}/bitable/tables`, {
+      headers: { Authorization: `Bearer ${token}` },
+    })
+    const tablesJson = (await tablesResp.json()) as { tables: { id: string; name: string }[] }
+    const table = tablesJson.tables[0]
+    const fieldsResp = await fetch(`${apiBase}/bitable/tables/${table.id}/fields`, {
+      headers: { Authorization: `Bearer ${token}` },
+    })
+    const fieldsJson = (await fieldsResp.json()) as { fields: IField[] }
+    return { tableId: table.id, fields: fieldsJson.fields }
+  }, API_BASE_STR)
+  return { tableId, fields }
+}
+
+async function createRecordViaApi(
+  page: Page,
+  tableId: string,
+  values: Record<string, unknown>,
+): Promise<IRecord> {
+  return await page.evaluate(
+    async ({ tableId, values, apiBase }) => {
+      const token = localStorage.getItem('agentkit.access_token') ?? ''
+      const resp = await fetch(`${apiBase}/bitable/tables/${tableId}/records`, {
+        method: 'POST',
+        headers: {
+          Authorization: `Bearer ${token}`,
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({ records: [values] }),
+      })
+      const json = (await resp.json()) as { records: IRecord[] }
+      return json.records[0]
+    },
+    { tableId, values, apiBase: API_BASE_STR },
+  )
+}
+
+async function createFieldViaApi(
+  page: Page,
+  tableId: string,
+  name: string,
+  fieldType: string,
+  owner: string = 'user',
+): Promise<IField> {
+  return await page.evaluate(
+    async ({ tableId, name, fieldType, owner, apiBase }) => {
+      const token = localStorage.getItem('agentkit.access_token') ?? ''
+      const resp = await fetch(`${apiBase}/bitable/tables/${tableId}/fields`, {
+        method: 'POST',
+        headers: {
+          Authorization: `Bearer ${token}`,
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({ name, field_type: fieldType, owner }),
+      })
+      const json = (await resp.json()) as { field: IField }
+      return json.field
+    },
+    { tableId, name, fieldType, owner, apiBase: API_BASE_STR },
+  )
+}
+
+async function reloadGrid(page: Page): Promise<void> {
+  await page.reload()
+  await expect(page.locator('.bitable-grid-scope')).toBeVisible({ timeout: 15_000 })
+}
+
+test.describe('Bitable Record Detail Drawer E2E (U3)', () => {
+  test.beforeAll(async () => {
+    try {
+      await waitForServer(undefined, 5_000)
+    } catch {
+      test.skip(true, 'Backend not running — skipping record drawer E2E')
+    }
+  })
+
+  test('D1: clicking a row seq cell opens the drawer with all fields', async ({ page }) => {
+    const { tableId, fields } = await loginAndCreateTable(page, 'E2E抽屉打开', '测试表')
+    const titleField = fields.find((f) => f.field_type === 'text')!
+    await createRecordViaApi(page, tableId, { [titleField.id]: '测试记录1' })
+    await reloadGrid(page)
+
+    // Click the seq cell (row number column) of the first data row.
+    const seqCell = page.locator('.vxe-body--column.col--seq').first()
+    await expect(seqCell).toBeVisible({ timeout: 10_000 })
+    await seqCell.click()
+
+    // Drawer opens
+    await expect(page.locator('.record-detail-drawer')).toBeVisible({ timeout: 5_000 })
+    // The sticky header shows the record title
+    await expect(page.locator('.record-detail-drawer__header-title')).toContainText(
+      '测试记录1',
+      { timeout: 5_000 },
+    )
+    // Field labels are rendered (default table has 5 fields incl. attachment-free types)
+    await expect(page.locator('.record-detail-drawer__field')).toHaveCount(5, {
+      timeout: 5_000,
+    })
+  })
+
+  test('D2: attachment/image fields render thumbnails, not raw URLs', async ({ page }) => {
+    const { tableId, fields } = await loginAndCreateTable(page, 'E2E附件图片', '测试表')
+    const titleField = fields.find((f) => f.field_type === 'text')!
+    // Add attachment + image fields
+    const attachmentField = await createFieldViaApi(page, tableId, '附件', 'attachment')
+    const imageField = await createFieldViaApi(page, tableId, '图片', 'image')
+
+    // Seed a record with attachment/image metadata
+    await createRecordViaApi(page, tableId, {
+      [titleField.id]: '带附件记录',
+      [attachmentField.id]: [{ filename: 'doc.pdf', url: '/files/doc.pdf', size: 1024 }],
+      [imageField.id]: [{ filename: 'pic.png', url: '/files/pic.png', size: 2048 }],
+    })
+    await reloadGrid(page)
+
+    await page.locator('.vxe-body--column.col--seq').first().click()
+    await expect(page.locator('.record-detail-drawer')).toBeVisible({ timeout: 5_000 })
+
+    // Attachment cell renders a download link (not a raw URL string)
+    await expect(page.locator('.record-detail-drawer .attachment-cell__link')).toHaveCount(
+      1,
+      { timeout: 5_000 },
+    )
+    // Image cell renders a thumbnail <img>
+    await expect(page.locator('.record-detail-drawer .image-cell__thumb')).toHaveCount(1, {
+      timeout: 5_000,
+    })
+  })
+
+  test('D3: formula field renders read-only (no input control)', async ({ page }) => {
+    const { tableId, fields } = await loginAndCreateTable(page, 'E2E公式只读', '测试表')
+    const titleField = fields.find((f) => f.field_type === 'text')!
+    const numberField = fields.find((f) => f.field_type === 'number')
+    // Add a number field + a formula field referencing it
+    const numField = numberField ?? (await createFieldViaApi(page, tableId, '数值', 'number'))
+    const formulaField = await createFieldViaApi(
+      page,
+      tableId,
+      '公式',
+      'formula',
+    )
+    await createRecordViaApi(page, tableId, {
+      [titleField.id]: '公式记录',
+      [numField.id]: 42,
+      // formula value is computed server-side; seed a cached value for display
+      [formulaField.id]: 84,
+    })
+    await reloadGrid(page)
+
+    await page.locator('.vxe-body--column.col--seq').first().click()
+    await expect(page.locator('.record-detail-drawer')).toBeVisible({ timeout: 5_000 })
+
+    // The formula field's value row must NOT contain an editable input.
+    const formulaRow = page
+      .locator('.record-detail-drawer__field')
+      .filter({ hasText: '公式' })
+    await expect(formulaRow).toBeVisible({ timeout: 5_000 })
+    await expect(formulaRow.locator('input')).toHaveCount(0)
+    // The computed value is shown as read-only text
+    await expect(formulaRow.locator('.record-detail-drawer__readonly')).toContainText('84')
+  })
+
+  test('D4: editing a user-owned field preserves agent columns', async ({ page }) => {
+    const { tableId, fields } = await loginAndCreateTable(page, 'E2E保留agent列', '测试表')
+    const titleField = fields.find((f) => f.field_type === 'text')!
+    const agentField = fields.find((f) => f.owner === 'agent')!
+    await createRecordViaApi(page, tableId, {
+      [titleField.id]: '编辑前标题',
+      [agentField.id]: 'AGENT_VALUE',
+    })
+    await reloadGrid(page)
+
+    await page.locator('.vxe-body--column.col--seq').first().click()
+    await expect(page.locator('.record-detail-drawer')).toBeVisible({ timeout: 5_000 })
+
+    // Edit the user-owned title field
+    const titleInput = page.locator('.record-detail-drawer__field').first().locator('input')
+    await titleInput.fill('编辑后标题')
+    await page.locator('.record-detail-drawer__footer').getByRole('button', { name: '保存' }).click()
+
+    // Drawer closes on success
+    await expect(page.locator('.record-detail-drawer')).toHaveCount(0, { timeout: 10_000 })
+
+    // Re-open the drawer — agent column must still show AGENT_VALUE
+    await page.locator('.vxe-body--column.col--seq').first().click()
+    await expect(page.locator('.record-detail-drawer')).toBeVisible({ timeout: 5_000 })
+    const agentRow = page
+      .locator('.record-detail-drawer__field')
+      .filter({ hasText: agentField.name })
+    await expect(agentRow).toContainText('AGENT_VALUE', { timeout: 5_000 })
+  })
+
+  test('D5: drawer width is 480px when field count <= 10', async ({ page }) => {
+    const { tableId, fields } = await loginAndCreateTable(page, 'E2E宽度480', '测试表')
+    const titleField = fields.find((f) => f.field_type === 'text')!
+    await createRecordViaApi(page, tableId, { [titleField.id]: '宽度测试' })
+    await reloadGrid(page)
+
+    await page.locator('.vxe-body--column.col--seq').first().click()
+    const drawer = page.locator('.record-detail-drawer')
+    await expect(drawer).toBeVisible({ timeout: 5_000 })
+
+    // Default table has 5 fields (<=10). Resolved width should be 480px.
+    const width = await drawer.evaluate((el) => {
+      // The a-drawer width is applied to the .ant-drawer-content wrapper.
+      const content = el.querySelector('.ant-drawer-content') ?? el
+      return getComputedStyle(content).width
+    })
+    expect(width).toBe('480px')
+  })
+
+  test('D6: drawer width is 640px when field count > 10', async ({ page }) => {
+    const { tableId, fields } = await loginAndCreateTable(page, 'E2E宽度640', '测试表')
+    const titleField = fields.find((f) => f.field_type === 'text')!
+    // Default table has 5 fields; add 7 more to exceed 10.
+    for (let i = 0; i < 7; i++) {
+      await createFieldViaApi(page, tableId, `扩展字段${i}`, 'text')
+    }
+    await createRecordViaApi(page, tableId, { [titleField.id]: '宽屏测试' })
+    await reloadGrid(page)
+
+    await page.locator('.vxe-body--column.col--seq').first().click()
+    const drawer = page.locator('.record-detail-drawer')
+    await expect(drawer).toBeVisible({ timeout: 5_000 })
+
+    const width = await drawer.evaluate((el) => {
+      const content = el.querySelector('.ant-drawer-content') ?? el
+      return getComputedStyle(content).width
+    })
+    expect(width).toBe('640px')
+  })
+
+  test('D7: Esc closes the drawer', async ({ page }) => {
+    const { tableId, fields } = await loginAndCreateTable(page, 'E2E Esc关闭', '测试表')
+    const titleField = fields.find((f) => f.field_type === 'text')!
+    await createRecordViaApi(page, tableId, { [titleField.id]: 'Esc测试' })
+    await reloadGrid(page)
+
+    await page.locator('.vxe-body--column.col--seq').first().click()
+    await expect(page.locator('.record-detail-drawer')).toBeVisible({ timeout: 5_000 })
+
+    await page.keyboard.press('Escape')
+    await expect(page.locator('.record-detail-drawer')).toHaveCount(0, { timeout: 5_000 })
+  })
+})
diff --git a/src/agentkit/server/frontend/src/components/bitable/BitableGrid.vue b/src/agentkit/server/frontend/src/components/bitable/BitableGrid.vue
index 5a72d52..824473e 100644
--- a/src/agentkit/server/frontend/src/components/bitable/BitableGrid.vue
+++ b/src/agentkit/server/frontend/src/components/bitable/BitableGrid.vue
@@ -17,6 +17,7 @@
         autoClear: false,
       }"
       @edit-closed="onEditClosed"
+      @cell-click="onCellClick"
     >
       <template #empty>
         <a-empty :description="emptyText" />
@@ -98,6 +99,16 @@
         </div>
       </template>
     </vxe-grid>
+
+    <!-- U3: Record detail drawer — opened by clicking the row's seq cell.
+         Rendered here so the grid is self-contained; reads state from the
+         bitable store (currentRecordId / currentRecord / fields). -->
+    <RecordDetailDrawer
+      :record-id="store.currentRecordId"
+      :open="!!store.currentRecordId"
+      @close="store.closeRecordDetail"
+      @retry="onDrawerRetry"
+    />
   </div>
 </template>
 
@@ -113,12 +124,14 @@ import type {
   IAttachmentMeta,
   FieldType,
 } from '@/api/bitable'
+import { useBitableStore } from '@/stores/bitable'
 import AttachmentCell from './AttachmentCell.vue'
 import ImageCell from './ImageCell.vue'
 import ColumnHeaderMenu from './ColumnHeaderMenu.vue'
 import SelectCellEditor from './SelectCellEditor.vue'
 import SelectDisplay from './SelectDisplay.vue'
 import InlineFieldConfigurator from './InlineFieldConfigurator.vue'
+import RecordDetailDrawer from './RecordDetailDrawer.vue'
 import type { ISelectOption } from './SelectCellEditor.vue'
 
 type GridRow = Record<string, unknown> & { _rowId: string; _recordId: string }
@@ -149,6 +162,31 @@ const emit = defineEmits<{
 
 const gridRef = ref<InstanceType<typeof VxeGrid> | null>(null)
 
+// U3: bitable store — used only for the record detail drawer (currentRecordId
+// + closeRecordDetail). The grid itself remains a controlled component
+// (fields/records via props); the drawer is the one side-effect surface.
+const store = useBitableStore()
+
+// U3: clicking the row's seq cell (#) opens the record detail drawer.
+// ponytail: data cells are NOT triggers — vxe-table's edit-config trigger:'click'
+// already owns the click-to-edit behaviour on data cells, so using the seq
+// column avoids a conflict. Ceiling: users must click the row number to open
+// the drawer (clicking a data cell enters edit mode instead). This matches
+// Feishu/Twenty's row-number → detail affordance. Upgrade path: add a
+// dedicated expand affordance if user testing shows discoverability issues.
+const onCellClick: VxeGridEvents.CellClick = (params) => {
+  const { row, column } = params
+  // column.type === 'seq' identifies the row-number column.
+  if (!column || column.type !== 'seq') return
+  const recordId = (row as GridRow)._recordId
+  if (!recordId) return
+  store.openRecordDetail(recordId)
+}
+
+function onDrawerRetry(recordId: string): void {
+  store.fetchRecordDetail(recordId)
+}
+
 // U2: inline field config — only one column edits at a time. null = none open.
 // The InlineFieldConfigurator renders inside an a-popover anchored to the
 // column header (see header slot above). The store mutation (store.updateField)
@@ -348,6 +386,13 @@ defineExpose({
   color: var(--bitable-color-primary);
 }
 
+/* U3: seq column (#) is the row-detail affordance — pointer cursor signals
+   clickability without a dedicated expand icon. */
+.bitable-grid-scope :deep(.vxe-header--column.col--seq),
+.bitable-grid-scope :deep(.vxe-body--column.col--seq) {
+  cursor: pointer;
+}
+
 .bitable-grid-scope__add-col {
   display: flex;
   align-items: center;
diff --git a/src/agentkit/server/frontend/src/components/bitable/RecordDetailDrawer.vue b/src/agentkit/server/frontend/src/components/bitable/RecordDetailDrawer.vue
new file mode 100644
index 0000000..523410d
--- /dev/null
+++ b/src/agentkit/server/frontend/src/components/bitable/RecordDetailDrawer.vue
@@ -0,0 +1,385 @@
+<template>
+  <a-drawer
+    :open="open"
+    :width="drawerWidth"
+    :keyboard="true"
+    :mask-closable="true"
+    :body-style="{ padding: 0 }"
+    placement="right"
+    class="record-detail-drawer"
+    :class="{ 'record-detail-drawer--wide': isWideDrawer }"
+    @close="onClose"
+  >
+    <template #title>
+      <span class="record-detail-drawer__title">
+        {{ headerTitle }}
+      </span>
+    </template>
+
+    <!-- Loading: skeleton (U1 LoadingState, Open Question P1) -->
+    <LoadingState v-if="store.recordDetailLoading" :rows="6" :title="true" />
+
+    <!-- 404: record not found / concurrently deleted -->
+    <div
+      v-else-if="store.recordDetailNotFound"
+      class="record-detail-drawer__notfound"
+    >
+      <a-empty description="记录不存在或已被删除" />
+      <a-button type="primary" @click="onClose">关闭</a-button>
+    </div>
+
+    <!-- Error: 5xx / network — ErrorState + retry (U1 ErrorState) -->
+    <ErrorState
+      v-else-if="store.recordDetailError"
+      :message="store.recordDetailError"
+      :retrying="store.recordDetailLoading"
+      @retry="retry"
+    />
+
+    <!-- Ready: render fields -->
+    <template v-else-if="record">
+      <!-- Empty: 0 fields (Open Question P2) -->
+      <div v-if="fields.length === 0" class="record-detail-drawer__empty">
+        <a-empty description="该记录暂无字段数据" />
+      </div>
+
+      <template v-else>
+        <!-- Sticky header: record title -->
+        <div class="record-detail-drawer__header">
+          <span class="record-detail-drawer__header-title">{{ recordTitle }}</span>
+        </div>
+
+        <!-- Body: vertical field list -->
+        <a-form
+          layout="vertical"
+          class="record-detail-drawer__form"
+          @submit.prevent="onSubmit"
+        >
+          <a-form-item
+            v-for="f in fields"
+            :key="f.id"
+            class="record-detail-drawer__field"
+          >
+            <template #label>
+              <span class="record-detail-drawer__field-label">
+                <FieldTypeIcon :type="f.field_type" />
+                {{ f.name }}
+              </span>
+            </template>
+            <!-- Read-only renders -->
+            <template v-if="!isEditable(f)">
+              <SelectDisplay
+                v-if="f.field_type === 'select' || f.field_type === 'multiselect'"
+                :value="(record.values[f.id] as string | string[] | null | undefined)"
+                :options="(f.config.options as ISelectOption[] | string[] | undefined)"
+                :multiple="f.field_type === 'multiselect'"
+              />
+              <AttachmentCell
+                v-else-if="f.field_type === 'attachment'"
+                :files="(record.values[f.id] as IAttachmentMeta[] | null | undefined)"
+              />
+              <ImageCell
+                v-else-if="f.field_type === 'image'"
+                :images="(record.values[f.id] as IAttachmentMeta[] | null | undefined)"
+              />
+              <span v-else class="record-detail-drawer__readonly">
+                {{ formatFieldValue(record.values[f.id], f.field_type) }}
+              </span>
+              <span v-if="isAgentOwned(f)" class="record-detail-drawer__owner-tag">
+                系统字段
+              </span>
+            </template>
+
+            <!-- Editable inputs (user-owned, non-computed).
+                 :value + @update:value with explicit casts — avoids `any`
+                 while satisfying each component's prop type. -->
+            <template v-else>
+              <a-input
+                v-if="f.field_type === 'text'"
+                :value="(editBuffer[f.id] as string | undefined)"
+                :disabled="submitting"
+                placeholder="请输入"
+                @update:value="editBuffer[f.id] = $event"
+              />
+              <a-input-number
+                v-else-if="f.field_type === 'number'"
+                :value="(editBuffer[f.id] as number | undefined)"
+                :disabled="submitting"
+                style="width: 100%"
+                placeholder="请输入数字"
+                @update:value="editBuffer[f.id] = $event"
+              />
+              <a-date-picker
+                v-else-if="f.field_type === 'date'"
+                :value="(editBuffer[f.id] as string | undefined)"
+                value-format="YYYY-MM-DD"
+                :disabled="submitting"
+                style="width: 100%"
+                placeholder="请选择日期"
+                @update:value="editBuffer[f.id] = $event"
+              />
+              <a-select
+                v-else-if="f.field_type === 'select'"
+                :value="(editBuffer[f.id] as string | undefined)"
+                :options="toSelectOptions(f.config.options)"
+                :disabled="submitting"
+                :allow-clear="true"
+                placeholder="请选择"
+                @update:value="editBuffer[f.id] = $event"
+              />
+              <a-select
+                v-else-if="f.field_type === 'multiselect'"
+                :value="(editBuffer[f.id] as string[] | undefined)"
+                :options="toSelectOptions(f.config.options)"
+                :disabled="submitting"
+                :allow-clear="true"
+                mode="multiple"
+                placeholder="请选择"
+                @update:value="editBuffer[f.id] = $event"
+              />
+            </template>
+          </a-form-item>
+        </a-form>
+      </template>
+    </template>
+
+    <!-- Footer: save button (only when ready + has editable fields) -->
+    <template v-if="showFooter" #footer>
+      <div class="record-detail-drawer__footer">
+        <a-button :disabled="submitting" @click="onClose">取消</a-button>
+        <a-button
+          type="primary"
+          :loading="submitting"
+          :disabled="submitting"
+          @click="onSubmit"
+        >
+          保存
+        </a-button>
+      </div>
+    </template>
+  </a-drawer>
+</template>
+
+<script setup lang="ts">
+import { computed, reactive, ref, watch } from 'vue'
+import {
+  Drawer as ADrawer,
+  Form as AForm,
+  FormItem as AFormItem,
+  Input as AInput,
+  InputNumber as AInputNumber,
+  DatePicker as ADatePicker,
+  Select as ASelect,
+  Button as AButton,
+  Empty as AEmpty,
+} from 'ant-design-vue'
+import type { IAttachmentMeta, IBitableField, IBitableRecord } from '@/api/bitable'
+import { useBitableStore } from '@/stores/bitable'
+import { useResponsiveBreakpoint } from '@/composables/useResponsiveBreakpoint'
+import LoadingState from './LoadingState.vue'
+import ErrorState from './ErrorState.vue'
+import FieldTypeIcon from './FieldTypeIcon.vue'
+import SelectDisplay from './SelectDisplay.vue'
+import AttachmentCell from './AttachmentCell.vue'
+import ImageCell from './ImageCell.vue'
+import type { ISelectOption } from './SelectCellEditor.vue'
+import {
+  formatFieldValue,
+  getDrawerWidth,
+  getRecordTitle,
+  isFieldEditable,
+} from '@/helpers/recordDrawerUtils'
+
+const props = defineProps<{
+  /** Record id to display. When non-null + open, the drawer fetches the record. */
+  recordId: string | null
+  /** Open signal — typically `!!store.currentRecordId`. */
+  open: boolean
+}>()
+
+const emit = defineEmits<{
+  (e: 'close'): void
+  (e: 'retry', recordId: string): void
+}>()
+
+const store = useBitableStore()
+const { isMobile } = useResponsiveBreakpoint()
+
+const submitting = ref(false)
+
+// Edit buffer: keyed by field id, only populated for editable fields.
+// Reset whenever the loaded record changes (watch below).
+const editBuffer = reactive<Record<string, unknown>>({})
+
+const record = computed<IBitableRecord | null>(() => store.currentRecord)
+const fields = computed<IBitableField[]>(() => store.fields)
+
+const isWideDrawer = computed(() => fields.value.length > 10)
+const drawerWidth = computed(() => getDrawerWidth(fields.value.length, isMobile.value))
+
+const recordTitle = computed(() =>
+  record.value ? getRecordTitle(record.value, fields.value) : '记录详情',
+)
+
+const headerTitle = computed(() => {
+  if (store.recordDetailLoading) return '加载中...'
+  if (store.recordDetailNotFound) return '记录不存在'
+  if (store.recordDetailError) return '加载失败'
+  return recordTitle.value
+})
+
+const showFooter = computed(
+  () =>
+    !!record.value &&
+    fields.value.length > 0 &&
+    fields.value.some(isEditable),
+)
+
+function isEditable(f: IBitableField): boolean {
+  return isFieldEditable(f)
+}
+
+function isAgentOwned(f: IBitableField): boolean {
+  return f.owner === 'agent'
+}
+
+function toSelectOptions(
+  raw: unknown,
+): { label: string; value: string }[] {
+  if (!Array.isArray(raw)) return []
+  return raw.map((opt) => {
+    if (typeof opt === 'string') return { label: opt, value: opt }
+    const o = opt as ISelectOption
+    return { label: o.label ?? o.value, value: o.value }
+  })
+}
+
+// Reset + hydrate the edit buffer when a new record loads.
+watch(
+  record,
+  (rec) => {
+    // Clear stale edits
+    for (const k of Object.keys(editBuffer)) {
+      delete editBuffer[k]
+    }
+    if (!rec) return
+    for (const f of fields.value) {
+      if (!isEditable(f)) continue
+      // Clone primitive values; clone arrays so multiselect edits don't
+      // mutate the store's record.
+      const v = rec.values[f.id]
+      editBuffer[f.id] = Array.isArray(v) ? [...v] : (v ?? undefined)
+    }
+  },
+  { immediate: true },
+)
+
+// If the drawer is re-opened for the same record id while the store still
+// holds it, the watch above won't fire (record ref unchanged). Re-hydrate
+// on open transition too.
+watch(
+  () => props.open,
+  (isOpen) => {
+    if (isOpen && record.value) {
+      // Re-trigger hydration by reassigning via the record watch.
+      for (const k of Object.keys(editBuffer)) delete editBuffer[k]
+      for (const f of fields.value) {
+        if (!isEditable(f)) continue
+        const v = record.value.values[f.id]
+        editBuffer[f.id] = Array.isArray(v) ? [...v] : (v ?? undefined)
+      }
+    }
+  },
+)
+
+function onClose(): void {
+  emit('close')
+}
+
+function retry(): void {
+  if (props.recordId) emit('retry', props.recordId)
+}
+
+async function onSubmit(): Promise<void> {
+  if (!record.value || !props.recordId) return
+  submitting.value = true
+  try {
+    // Only submit editable user-owned fields. Agent columns are merged back
+    // from currentRecord.values inside updateRecordFields (preserves them).
+    const edited: Record<string, unknown> = {}
+    for (const f of fields.value) {
+      if (!isEditable(f)) continue
+      if (f.id in editBuffer) edited[f.id] = editBuffer[f.id]
+    }
+    const ok = await store.updateRecordFields(props.recordId, edited)
+    if (ok) {
+      emit('close')
+    }
+  } finally {
+    submitting.value = false
+  }
+}
+</script>
+
+<style scoped>
+.record-detail-drawer__title {
+  font-size: var(--bitable-font-md);
+  font-weight: 600;
+  color: var(--bitable-color-text);
+}
+
+.record-detail-drawer__header {
+  position: sticky;
+  top: 0;
+  z-index: 2;
+  background: var(--bitable-color-bg);
+  border-bottom: 1px solid var(--bitable-color-border);
+  padding: var(--bitable-spacing-md) var(--bitable-spacing-lg);
+}
+
+.record-detail-drawer__header-title {
+  font-size: var(--bitable-font-lg);
+  font-weight: 600;
+  color: var(--bitable-color-text);
+  word-break: break-all;
+}
+
+.record-detail-drawer__form {
+  padding: var(--bitable-spacing-md) var(--bitable-spacing-lg);
+}
+
+.record-detail-drawer__field {
+  margin-bottom: var(--bitable-spacing-lg);
+}
+
+.record-detail-drawer__readonly {
+  color: var(--bitable-color-text);
+  word-break: break-word;
+  white-space: pre-wrap;
+}
+
+.record-detail-drawer__owner-tag {
+  display: inline-block;
+  margin-left: var(--bitable-spacing-sm);
+  padding: 0 var(--bitable-spacing-xs);
+  font-size: var(--bitable-font-xs);
+  color: var(--bitable-color-text-tertiary);
+  background: var(--bitable-color-bg-tertiary);
+  border-radius: var(--bitable-radius-sm);
+}
+
+.record-detail-drawer__notfound,
+.record-detail-drawer__empty {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: var(--bitable-spacing-md);
+  padding: var(--bitable-spacing-xl) var(--bitable-spacing-lg);
+}
+
+.record-detail-drawer__footer {
+  display: flex;
+  justify-content: flex-end;
+  gap: var(--bitable-spacing-sm);
+}
+</style>
diff --git a/src/agentkit/server/frontend/src/helpers/recordDrawerUtils.ts b/src/agentkit/server/frontend/src/helpers/recordDrawerUtils.ts
new file mode 100644
index 0000000..9652793
--- /dev/null
+++ b/src/agentkit/server/frontend/src/helpers/recordDrawerUtils.ts
@@ -0,0 +1,169 @@
+/**
+ * RecordDetailDrawer pure helpers (U3 / R2).
+ *
+ * Pure functions — no Vue, no store, no I/O. Safe to unit-test in isolation.
+ *
+ * Responsibilities:
+ * - formatFieldValue: text/number/date/select/multiselect/formula/lookup → display string
+ * - getAttachmentFileList / getImageThumbnailList: normalize attachment/image
+ *   field values (which may be IAttachmentMeta[] or stale legacy shapes) into
+ *   a uniform {name, url} / {url, alt} list for the drawer.
+ * - getRecordTitle: first text-type field value, fallback "未命名记录".
+ * - isFieldEditable: user-owned fields are editable; agent-owned + formula +
+ *   lookup are read-only (formula/lookup are computed, not user data).
+ * - getDrawerWidth: '100vw' on mobile, else 480px (≤10 fields) / 640px (>10).
+ *
+ * ponytail: width returns a CSS var() reference, not a hardcoded px value, so
+ * the design token in bitable-tokens.css stays the single source of truth.
+ * Ceiling: the field-count threshold (10) is hardcoded per KTD4 spec; if the
+ * token name or threshold changes, update both here and the spec.
+ */
+
+import type { FieldType, IAttachmentMeta, IBitableField, IBitableRecord } from '@/api/bitable'
+
+const DRAWER_FIELD_COUNT_THRESHOLD = 10
+
+export interface IAttachmentFileView {
+  name: string
+  url: string
+  size?: number
+}
+
+export interface IImageView {
+  url: string
+  alt?: string
+}
+
+function isEmptyValue(v: unknown): boolean {
+  return v == null || v === '' || (Array.isArray(v) && v.length === 0)
+}
+
+/**
+ * Format a field value for read-only display in the drawer.
+ *
+ * - text/number/formula/lookup: coerce to string, empty → '—'
+ * - date: pass through (ISO string); the drawer may format further, but we
+ *   return the raw stored value so callers can apply a consistent formatter.
+ *   ponytail: no dayjs dependency here — the drawer renders the ISO string
+ *   directly to avoid pulling a date lib into a pure helper. Upgrade path:
+ *   if a shared date formatter exists, call it from the drawer component.
+ * - select/multiselect: return label joined by ' / '; empty → '—'
+ * - attachment/image: return `${n} 个文件` summary (the drawer renders the
+ *   file list separately via getAttachmentFileList / getImageThumbnailList)
+ */
+export function formatFieldValue(
+  value: unknown,
+  fieldType: FieldType,
+  options?: { labelOf?: (v: string) => string },
+): string {
+  if (isEmptyValue(value)) return '—'
+
+  switch (fieldType) {
+    case 'text':
+    case 'number':
+    case 'formula':
+    case 'lookup':
+      return String(value)
+    case 'date':
+      return typeof value === 'string' ? value : String(value)
+    case 'select': {
+      const v = value as string
+      return options?.labelOf ? options.labelOf(v) : v
+    }
+    case 'multiselect': {
+      const arr = value as string[]
+      const labels = arr.map((v) => (options?.labelOf ? options.labelOf(v) : v))
+      return labels.join(' / ')
+    }
+    case 'attachment':
+    case 'image': {
+      const arr = value as IAttachmentMeta[]
+      return `${arr.length} 个文件`
+    }
+    default:
+      return String(value)
+  }
+}
+
+/**
+ * Normalize an attachment field value into a uniform file view list.
+ *
+ * Accepts IAttachmentMeta[] (the canonical shape). Defensively tolerates
+ * legacy / malformed entries (missing url → skipped, missing filename →
+ * fallback to stored_name or '未命名文件').
+ */
+export function getAttachmentFileList(value: unknown): IAttachmentFileView[] {
+  if (!Array.isArray(value)) return []
+  const out: IAttachmentFileView[] = []
+  for (const raw of value) {
+    if (!raw || typeof raw !== 'object') continue
+    const m = raw as Partial<IAttachmentMeta>
+    if (!m.url) continue
+    out.push({
+      name: m.filename || m.stored_name || '未命名文件',
+      url: m.url,
+      size: typeof m.size === 'number' ? m.size : undefined,
+    })
+  }
+  return out
+}
+
+/**
+ * Normalize an image field value into a uniform thumbnail view list.
+ *
+ * Reuses getAttachmentFileList logic; image thumbnails use the same
+ * IAttachmentMeta shape (url + filename). `alt` falls back to filename.
+ */
+export function getImageThumbnailList(value: unknown): IImageView[] {
+  return getAttachmentFileList(value).map((f) => ({
+    url: f.url,
+    alt: f.name,
+  }))
+}
+
+/**
+ * Return the record's title — the value of the first text-type field, or
+ * "未命名记录" if none exists / value is empty.
+ */
+export function getRecordTitle(record: IBitableRecord, fields: IBitableField[]): string {
+  const firstText = fields.find((f) => f.field_type === 'text')
+  if (!firstText) return '未命名记录'
+  const v = record.values[firstText.id]
+  if (isEmptyValue(v)) return '未命名记录'
+  return String(v)
+}
+
+/**
+ * A field is editable in the drawer iff:
+ * - owner === 'user' (agent-owned columns are managed by the backend / agents)
+ * - field_type is NOT formula (computed) or lookup (derived from another table)
+ *
+ * attachment/image are NOT inline-editable from the drawer in P0 (file upload
+ * flow is out of scope for U3 — ponytail: ceiling noted, upgrade path = add
+ * an upload control in a follow-up U-ID).
+ */
+export function isFieldEditable(field: IBitableField): boolean {
+  if (field.owner !== 'user') return false
+  if (field.field_type === 'formula' || field.field_type === 'lookup') return false
+  if (field.field_type === 'attachment' || field.field_type === 'image') return false
+  return true
+}
+
+/**
+ * Compute the drawer width.
+ *
+ * @param fieldCount number of fields rendered in the body
+ * @param isMobile   from useResponsiveBreakpoint — full-screen overlay when true
+ * @returns a CSS value string. On desktop/tablet, returns a var() reference
+ *          to --bitable-drawer-width (≤10 fields) or --bitable-drawer-width-wide
+ *          (>10 fields). On mobile, returns '100vw'.
+ */
+export function getDrawerWidth(fieldCount: number, isMobile: boolean): string {
+  if (isMobile) return '100vw'
+  return fieldCount > DRAWER_FIELD_COUNT_THRESHOLD
+    ? 'var(--bitable-drawer-width-wide)'
+    : 'var(--bitable-drawer-width)'
+}
+
+// ponytail self-check: width threshold + var() reference. The two var() names
+// must match bitable-tokens.css exactly. Trivial string logic, no test file.
diff --git a/src/agentkit/server/frontend/src/stores/bitable.ts b/src/agentkit/server/frontend/src/stores/bitable.ts
index 6b9e2fc..fde29b8 100644
--- a/src/agentkit/server/frontend/src/stores/bitable.ts
+++ b/src/agentkit/server/frontend/src/stores/bitable.ts
@@ -36,6 +36,16 @@ export const useBitableStore = defineStore('bitable', () => {
   const nextCursor = ref<string | null>(null)
   const recalcPendingCount = ref(0)
 
+  // U3: RecordDetailDrawer state. `currentRecordId` is the drawer's open
+  // signal — non-null means the drawer is open. `currentRecord` is the
+  // fully-hydrated record fetched by record_id (so the drawer sees agent
+  // columns even if the grid view hides them).
+  const currentRecordId = ref<string | null>(null)
+  const currentRecord = ref<IBitableRecord | null>(null)
+  const recordDetailLoading = ref(false)
+  const recordDetailError = ref<string | null>(null)
+  const recordDetailNotFound = ref(false)
+
   // Polling timer for formula recalc status
   let _pollTimer: ReturnType<typeof setInterval> | null = null
   const POLL_INTERVAL = 2000 // 2s per plan
@@ -391,6 +401,130 @@ export const useBitableStore = defineStore('bitable', () => {
     }
   }
 
+  // --- U3: Record detail drawer ---
+
+  /**
+   * Open the record detail drawer for a given record id.
+   *
+   * Sets the drawer open signal and triggers an async fetch of the full
+   * record (by record_id) so the drawer sees all fields including agent-
+   * owned columns that may be hidden in the grid view.
+   *
+   * ponytail: fetch is fire-and-forget — `currentRecord` is null until the
+   * request resolves, which the drawer renders as a skeleton (LoadingState).
+   * Ceiling: no debounce; rapid row-clicks fire one fetch per click. The
+   * drawer's watch on `currentRecordId` short-circuits stale fetches by
+   * checking the id still matches when the response arrives.
+   */
+  function openRecordDetail(recordId: string): void {
+    if (currentRecordId.value === recordId) return
+    currentRecordId.value = recordId
+    currentRecord.value = null
+    recordDetailLoading.value = true
+    recordDetailError.value = null
+    recordDetailNotFound.value = false
+    void fetchRecordDetail(recordId)
+  }
+
+  /** Close the drawer and clear all drawer state. */
+  function closeRecordDetail(): void {
+    currentRecordId.value = null
+    currentRecord.value = null
+    recordDetailLoading.value = false
+    recordDetailError.value = null
+    recordDetailNotFound.value = false
+  }
+
+  /**
+   * Fetch a single record by id.
+   *
+   * The bitable list endpoint doesn't expose a single-record GET, so this
+   * reuses `listRecords` and searches the result by id. 404 / empty result →
+   * notFound state; network error → error state (drawer shows ErrorState +
+   * retry).
+   *
+   * ponytail: fast path — the record is in the currently-loaded page
+   * (`records.value`), no network round-trip. Slow path — re-query the first
+   * 100 records and search. Ceiling: a record on a later page (cursor > 100)
+   * would 404-false. Acceptable for P0 because the drawer is opened from a
+   * visible grid row, so the record is always in the loaded page. Upgrade
+   * path: add GET /records/{id} when cross-page detail access is needed.
+   */
+  async function fetchRecordDetail(recordId: string): Promise<void> {
+    if (!currentTable.value) {
+      recordDetailLoading.value = false
+      recordDetailError.value = '未选择数据表'
+      return
+    }
+    recordDetailLoading.value = true
+    recordDetailError.value = null
+    recordDetailNotFound.value = false
+    try {
+      let found: IBitableRecord | null = null
+      // Fast path: record is in the currently-loaded page.
+      const local = records.value.find((r) => r.id === recordId)
+      if (local) {
+        found = local
+      } else if (currentTable.value) {
+        // Slow path: re-query the first 100 records and search by id.
+        // (See function docstring — ceiling noted.)
+        const resp = await bitableApi.listRecords(currentTable.value.id, { limit: 100 })
+        found = (resp.records || []).find((r) => r.id === recordId) ?? null
+      }
+
+      // Stale-response guard: if the user clicked another row while this
+      // fetch was in flight, drop the result.
+      if (currentRecordId.value !== recordId) return
+
+      if (!found) {
+        recordDetailNotFound.value = true
+      } else {
+        currentRecord.value = found
+      }
+    } catch (err) {
+      if (currentRecordId.value !== recordId) return
+      recordDetailError.value = err instanceof Error ? err.message : '加载记录详情失败'
+    } finally {
+      if (currentRecordId.value === recordId) {
+        recordDetailLoading.value = false
+      }
+    }
+  }
+
+  /**
+   * Save user-edited field values from the drawer.
+   *
+   * Merges the edited user-owned fields with the EXISTING agent-owned field
+   * values from `currentRecord` before PATCHing. This preserves agent
+   * columns: the backend's update_record_values does a full-replace of the
+   * values dict, so we send the agent columns back as-is rather than
+   * dropping them. (Spec: "upsert 保留 agent 列" — implemented client-side
+   * to avoid adding a new backend endpoint in U3.)
+   *
+   * Returns true on success. On success, both `currentRecord` and the
+   * matching entry in `records` are updated with the server response.
+   */
+  async function updateRecordFields(
+    recordId: string,
+    editedFields: Record<string, unknown>,
+  ): Promise<boolean> {
+    const base = currentRecord.value?.values ?? {}
+    const merged: Record<string, unknown> = { ...base, ...editedFields }
+    try {
+      const resp = await bitableApi.updateRecord(recordId, merged)
+      currentRecord.value = resp.record
+      const idx = records.value.findIndex((r) => r.id === recordId)
+      if (idx >= 0) records.value[idx] = resp.record
+      return true
+    } catch (err) {
+      notification.error({
+        message: '保存失败',
+        description: err instanceof Error ? err.message : String(err),
+      })
+      return false
+    }
+  }
+
   // --- View management (U5c) ---
 
   /** Create a new view for the current table */
@@ -521,6 +655,12 @@ export const useBitableStore = defineStore('bitable', () => {
     error,
     nextCursor,
     recalcPendingCount,
+    // U3: record detail drawer state
+    currentRecordId,
+    currentRecord,
+    recordDetailLoading,
+    recordDetailError,
+    recordDetailNotFound,
     // Getters
     formulaFields,
     hasFormulaFields,
@@ -543,6 +683,11 @@ export const useBitableStore = defineStore('bitable', () => {
     deleteField,
     hideField,
     refreshRecords,
+    // U3: record detail drawer actions
+    openRecordDetail,
+    closeRecordDetail,
+    fetchRecordDetail,
+    updateRecordFields,
     createView,
     updateView,
     switchView,