diff --git a/frontend/src/features/list/components/ActionSection.tsx b/frontend/src/features/list/components/ActionSection.tsx
index 36ce83c..5a52efc 100644
--- a/frontend/src/features/list/components/ActionSection.tsx
+++ b/frontend/src/features/list/components/ActionSection.tsx
@@ -5,17 +5,42 @@ const PILL =
   'text-lg font-semibold whitespace-nowrap ' +
   interactive
 
-export function ActionSection() {
+export interface ActionSectionProps {
+  isParticipating: boolean
+  isRejecting: boolean
+  onParticipate: () => void
+  onReject: () => void
+}
+
+export function ActionSection({
+  isParticipating,
+  isRejecting,
+  onParticipate,
+  onReject,
+}: ActionSectionProps) {
   return (
     <div className="flex w-full py-[35px] items-center justify-end gap-3">
-      {/* TODO: 협상 참여 동작 연동 */}
-      <button type="button" className={cn(PILL, 'bg-primary text-primary-foreground')}>
-        협상 참여
-      </button>
-      {/* TODO: 거부 동작 연동 */}
       <button
         type="button"
-        className={cn(PILL, 'bg-background text-primary border border-primary')}
+        onClick={onParticipate}
+        disabled={isParticipating}
+        className={cn(
+          PILL,
+          'bg-primary text-primary-foreground',
+          isParticipating && 'opacity-50 cursor-not-allowed',
+        )}
+      >
+        협상 참여
+      </button>
+      <button
+        type="button"
+        onClick={onReject}
+        disabled={isRejecting}
+        className={cn(
+          PILL,
+          'bg-background text-primary border border-primary',
+          isRejecting && 'opacity-50 cursor-not-allowed',
+        )}
       >
         거부
       </button>
diff --git a/frontend/src/features/list/components/RejectPopup.tsx b/frontend/src/features/list/components/RejectPopup.tsx
new file mode 100644
index 0000000..d7f2d45
--- /dev/null
+++ b/frontend/src/features/list/components/RejectPopup.tsx
@@ -0,0 +1,124 @@
+import { useState } from 'react'
+import { Modal } from '@/components'
+import { cn, interactive } from '@/lib'
+
+const REASONS = ['단종', '품절', '기타'] as const
+
+export interface RejectPopupProps {
+  onClose: () => void
+  /** 최종 거부 사유 (프리셋 라벨 또는 기타 입력 텍스트) */
+  onSubmit: (reason: string) => void
+}
+
+// 거부 사유 입력 팝업 (단종/품절/기타).
+export function RejectPopup({ onClose, onSubmit }: RejectPopupProps) {
+  const [selectedReason, setSelectedReason] = useState<string | null>(null)
+  const [customReason, setCustomReason] = useState('')
+  const [showError, setShowError] = useState(false)
+
+  const isEtcOpen = selectedReason === '기타'
+  const isSubmitDisabled = !selectedReason || (isEtcOpen && !customReason.trim())
+
+  const handleReasonClick = (reason: string) => {
+    setShowError(false)
+    if (selectedReason === reason) {
+      setSelectedReason(null)
+      setCustomReason('')
+    } else {
+      setSelectedReason(reason)
+      if (reason !== '기타') setCustomReason('')
+    }
+  }
+
+  const handleSubmit = () => {
+    if (isEtcOpen && !customReason.trim()) {
+      setShowError(true)
+      return
+    }
+    if (isSubmitDisabled || !selectedReason) return
+
+    const reason = isEtcOpen ? customReason.trim() : selectedReason
+    onSubmit(reason)
+    onClose()
+  }
+
+  return (
+    <Modal onClose={onClose}>
+      <div className="flex h-[500px] w-[700px] flex-col items-center justify-between rounded-[10px] bg-background py-20 shadow-lg transition-all duration-300 ease-out">
+        {/* 헤더 */}
+        <p className="text-center text-[26px] font-bold leading-9 tracking-[-0.52px] text-foreground">
+          거부 사유를 입력해주세요
+        </p>
+
+        {/* 사유 선택 */}
+        <div className={cn('flex gap-5 transition-all duration-300 ease-out', isEtcOpen ? 'mt-0' : 'mt-12')}>
+          {REASONS.map((reason) => (
+            <button
+              key={reason}
+              type="button"
+              onClick={() => handleReasonClick(reason)}
+              className={cn(
+                'flex h-[50px] w-[120px] items-center justify-center rounded-full px-8 title-2 text-foreground',
+                'bg-neutral-20 border',
+                interactive,
+                selectedReason === reason ? 'border-foreground' : 'border-transparent',
+              )}
+            >
+              {reason}
+            </button>
+          ))}
+        </div>
+
+        {/* 기타 입력 + 에러 */}
+        <div className="flex flex-col items-center">
+          <div
+            className={cn(
+              'flex w-[400px] overflow-hidden transition-all duration-300 ease-out',
+              isEtcOpen ? 'visible h-[120px] opacity-100' : 'invisible h-0 opacity-0',
+            )}
+          >
+            <textarea
+              placeholder="사유를 입력하여 주십시오"
+              value={customReason}
+              onChange={(e) => {
+                setCustomReason(e.target.value)
+                setShowError(false)
+              }}
+              className={cn(
+                'h-full w-full resize-none rounded-lg bg-background p-2.5 body-3 text-foreground',
+                'placeholder:text-muted-foreground focus:outline-none',
+                'transition-colors duration-200',
+                showError ? 'border-2 border-destructive' : 'border border-foreground',
+              )}
+            />
+          </div>
+
+          {/* 에러 메시지 (항상 공간 확보) */}
+          <div
+            className={cn(
+              'w-[400px] overflow-hidden transition-all duration-300 ease-out',
+              showError && isEtcOpen ? 'mt-2 h-[24px] opacity-100' : 'h-0 opacity-0',
+            )}
+          >
+            <p className="text-left body-5 text-destructive">기타 사유를 입력해주세요</p>
+          </div>
+        </div>
+
+        {/* 전송 */}
+        <button
+          type="button"
+          onClick={handleSubmit}
+          disabled={isSubmitDisabled}
+          className={cn(
+            'flex h-[50px] w-full max-w-[130px] items-center justify-center rounded-full px-8 title-2',
+            'bg-foreground text-background',
+            interactive,
+            isSubmitDisabled && 'cursor-not-allowed opacity-40',
+          )}
+        >
+          전송
+        </button>
+      </div>
+    </Modal>
+  )
+}
diff --git a/frontend/src/features/list/containers/ContentContainer.tsx b/frontend/src/features/list/containers/ContentContainer.tsx
index eb89662..c62644d 100644
--- a/frontend/src/features/list/containers/ContentContainer.tsx
+++ b/frontend/src/features/list/containers/ContentContainer.tsx
@@ -1,16 +1,92 @@
+import { useState } from 'react'
+import { useNavigate } from 'react-router'
+import { getApiErrorMessage, useParticipateMutation, useRejectMutation } from '@/apis'
+import { toast } from '@/lib'
 import { useList } from '@/features/list/hooks/useList'
 import { ActionSection } from '@/features/list/components/ActionSection'
+import { RejectPopup } from '@/features/list/components/RejectPopup'
 import { TableSection } from '@/features/list/components/TableSection'
 import { Pagination } from '@/features/list/components/Pagination'
 
+// 상태별 거부 불가 안내
+const REJECT_BLOCKED: Record<string, string> = {
+  미참여: '미참여 상태인 협상은 거부할 수 없습니다.',
+  협상거부: '협상거부 상태인 협상은 거부할 수 없습니다.',
+  협상완료: '협상완료 상태인 협상은 거부할 수 없습니다.',
+}
+
 export function ContentContainer() {
-  const { items, isLoading, totalPages, currentPage, setCurrentPage, selectedId, handleItemClick } =
-    useList()
+  const navigate = useNavigate()
+  const {
+    items,
+    isLoading,
+    totalPages,
+    currentPage,
+    setCurrentPage,
+    selectedId,
+    selectedItem,
+    handleItemClick,
+  } = useList()
+  const participate = useParticipateMutation()
+  const reject = useRejectMutation()
+  const [isRejectOpen, setIsRejectOpen] = useState(false)
+
+  // 선택 검증: 선택된 협상이 없으면 안내 후 false
+  const requireSelection = (): boolean => {
+    if (!selectedItem) {
+      toast.info('상품을 선택해주세요.')
+      return false
+    }
+    return true
+  }
+
+  const handleParticipate = () => {
+    if (!requireSelection()) return
+
+    if (['협상거부', '미참여'].includes(selectedItem!.session_status)) {
+      toast.error('협상거부 또는 미참여한 협상에는 참여할 수 없습니다.')
+      return
+    }
+
+    const sessionId = selectedItem!.session_id
+    participate.mutate(sessionId, {
+      onSuccess: () => navigate(`/chat?session_id=${sessionId}`),
+      onError: (error) => toast.error(getApiErrorMessage(error, '협상 참여에 실패했습니다.')),
+    })
+  }
+
+  const handleReject = () => {
+    if (!requireSelection()) return
+
+    const blocked = REJECT_BLOCKED[selectedItem!.session_status]
+    if (blocked) {
+      toast.error(blocked)
+      return
+    }
+    setIsRejectOpen(true)
+  }
+
+  const handleRejectSubmit = (reason: string) => {
+    if (!selectedItem) return
+
+    reject.mutate(
+      { sessionId: selectedItem.session_id, request: { reject_reason: reason } },
+      {
+        onSuccess: () => toast.warning('참여 거절이 완료되었습니다.'),
+        onError: (error) => toast.error(getApiErrorMessage(error, '거절 처리에 실패했습니다.')),
+      },
+    )
+  }
 
   return (
     // 좌우 거터(80px) 일괄 적용
     <div className="flex flex-1 flex-col min-h-0 px-[80px]">
-      <ActionSection />
+      <ActionSection
+        isParticipating={participate.isPending}
+        isRejecting={reject.isPending}
+        onParticipate={handleParticipate}
+        onReject={handleReject}
+      />
       <TableSection
         items={items}
         isLoading={isLoading}
@@ -22,6 +98,9 @@ export function ContentContainer() {
         currentPage={currentPage}
         onPageChange={setCurrentPage}
       />
+      {isRejectOpen && (
+        <RejectPopup onClose={() => setIsRejectOpen(false)} onSubmit={handleRejectSubmit} />
+      )}
     </div>
   )
 }
diff --git a/frontend/src/features/list/hooks/useList.ts b/frontend/src/features/list/hooks/useList.ts
index dc16832..b23bdad 100644
--- a/frontend/src/features/list/hooks/useList.ts
+++ b/frontend/src/features/list/hooks/useList.ts
@@ -1,40 +1,33 @@
 import { useMemo, useState } from 'react'
+import { useSessionListQuery } from '@/apis'
 import { useListStore } from '@/features/list/stores/useListStore'
-import { MOCK_ITEMS } from '@/features/list/mocks/mockItems'
+import {
+  deadlineToOrder,
+  statusLabelToCode,
+  toListItem,
+  typeLabelToCode,
+} from '@/features/list/lib/adapter'
 import type { ListItem } from '@/features/list/types'
 
 const PAGE_SIZE = 20
 
-// 목데이터 클라이언트 필터 (추후 API 조회로 교체)
+// 필터/정렬/페이지는 서버에 위임하고, 응답(정수 코드)을 화면용 라벨로 변환한다.
 export function useList() {
   const { selectedType, selectedStatus, selectedDeadline, currentPage, setCurrentPage } =
     useListStore()
   const [selectedId, setSelectedId] = useState<string | null>(null)
 
-  const filtered = useMemo(() => {
-    const result = MOCK_ITEMS.filter(
-      (item) =>
-        (!selectedType || item.qt_type === selectedType) &&
-        (!selectedStatus || item.session_status === selectedStatus),
-    )
+  const query = useSessionListQuery({
+    status: selectedStatus ? statusLabelToCode(selectedStatus) : undefined,
+    qt_type: selectedType ? typeLabelToCode(selectedType) : undefined,
+    order: selectedDeadline ? deadlineToOrder(selectedDeadline) : undefined,
+    page: currentPage,
+    page_size: PAGE_SIZE,
+  })
 
-    if (selectedDeadline) {
-      const dir = selectedDeadline === '남은 시간 적은 순' ? 1 : -1
-      result.sort(
-        (a, b) =>
-          (new Date(a.qt_end_time).getTime() - new Date(b.qt_end_time).getTime()) * dir,
-      )
-    }
-
-    return result
-  }, [selectedType, selectedStatus, selectedDeadline])
-
-  const totalPages = Math.max(1, Math.ceil(filtered.length / PAGE_SIZE))
-
-  const items = useMemo(
-    () => filtered.slice((currentPage - 1) * PAGE_SIZE, currentPage * PAGE_SIZE),
-    [filtered, currentPage],
-  )
+  const items = useMemo(() => (query.data?.items ?? []).map(toListItem), [query.data])
+  const total = query.data?.total ?? 0
+  const totalPages = Math.max(1, Math.ceil(total / PAGE_SIZE))
 
   const selectedItem = useMemo(
     () => items.find((item) => item.session_id === selectedId) ?? null,
@@ -46,7 +39,7 @@ export function useList() {
 
   return {
     items,
-    isLoading: false,
+    isLoading: query.isLoading,
     totalPages,
     currentPage,
     setCurrentPage,
diff --git a/frontend/src/features/list/lib/adapter.ts b/frontend/src/features/list/lib/adapter.ts
new file mode 100644
index 0000000..03d75ea
--- /dev/null
+++ b/frontend/src/features/list/lib/adapter.ts
@@ -0,0 +1,41 @@
+// 백엔드 정수 코드값 ↔ 리스트 UI 의 한국어 라벨 변환 어댑터.
+// 라벨 단일 출처는 apis 의 *_LABEL 맵이며, 필터 라벨(FILTER_GROUPS)도 이와 일치한다.
+import {
+  QT_TYPE_LABEL,
+  SESSION_STATUS_LABEL,
+  type QtType,
+  type SessionListItem,
+  type SessionStatus,
+} from '@/apis'
+import type { ListItem } from '@/features/list/types'
+
+const invert = (labelMap: Record<number, string>): Record<string, number> =>
+  Object.fromEntries(Object.entries(labelMap).map(([code, label]) => [label, Number(code)]))
+
+const STATUS_LABEL_TO_CODE = invert(SESSION_STATUS_LABEL)
+const TYPE_LABEL_TO_CODE = invert(QT_TYPE_LABEL)
+
+/** 필터 상태 라벨 → SessionStatus 코드 */
+export const statusLabelToCode = (label: string): number | undefined => STATUS_LABEL_TO_CODE[label]
+
+/** 필터 구분 라벨 → QtType 코드 */
+export const typeLabelToCode = (label: string): number | undefined => TYPE_LABEL_TO_CODE[label]
+
+/** 마감일 필터 라벨 → 정렬 방향 (임박순=asc) */
+export const deadlineToOrder = (label: string): 'asc' | 'desc' =>
+  label === '남은 시간 적은 순' ? 'asc' : 'desc'
+
+/** API 세션 항목(정수 코드) → 화면용 ListItem(한국어 라벨) */
+export function toListItem(api: SessionListItem): ListItem {
+  return {
+    session_id: api.session_id,
+    session_status: SESSION_STATUS_LABEL[api.session_status as SessionStatus] ?? '-',
+    qt_type: QT_TYPE_LABEL[api.qt_type as QtType] ?? '-',
+    qt_number: api.qt_number,
+    qt_end_time: api.qt_end_time,
+    item_code: api.item_code,
+    item_name: api.item_name,
+    model_name: api.model_name,
+    maker_name: api.maker_name,
+  }
+}
diff --git a/frontend/src/features/list/mocks/mockItems.ts b/frontend/src/features/list/mocks/mockItems.ts
deleted file mode 100644
index ece904b..0000000
--- a/frontend/src/features/list/mocks/mockItems.ts
+++ /dev/null
@@ -1,115 +0,0 @@
-import type { ListItem } from '@/features/list/types'
-
-// 임시 목데이터 (API 연동 전)
-export const MOCK_ITEMS: ListItem[] = [
-  {
-    session_id: 's-001',
-    session_status: '협상생성',
-    qt_type: '재견적',
-    qt_number: 'QT-2026-000101',
-    qt_end_time: '2026-06-18T18:00:00',
-    item_code: 'IMK-10231',
-    item_name: '사무용 노트북 14인치',
-    model_name: 'NB-1400-PRO',
-    maker_name: '삼성전자',
-  },
-  {
-    session_id: 's-002',
-    session_status: '협상중',
-    qt_type: '재협상',
-    qt_number: 'QT-2026-000102',
-    qt_end_time: '2026-06-17T12:30:00',
-    item_code: 'IMK-10232',
-    item_name: '레이저 복합기',
-    model_name: 'MFC-7890DW',
-    maker_name: '브라더',
-  },
-  {
-    session_id: 's-003',
-    session_status: '협상완료',
-    qt_type: '재견적',
-    qt_number: 'QT-2026-000103',
-    qt_end_time: '2026-06-20T09:00:00',
-    item_code: 'IMK-10233',
-    item_name: '27인치 4K 모니터',
-    model_name: 'U2723QE',
-    maker_name: '델',
-  },
-  {
-    session_id: 's-004',
-    session_status: '협상거부',
-    qt_type: '재협상',
-    qt_number: 'QT-2026-000104',
-    qt_end_time: '2026-06-19T15:45:00',
-    item_code: 'IMK-10234',
-    item_name: '무선 기계식 키보드',
-    model_name: 'MX-KEYS-M',
-    maker_name: '로지텍',
-  },
-  {
-    session_id: 's-005',
-    session_status: '미참여',
-    qt_type: '재견적',
-    qt_number: 'QT-2026-000105',
-    qt_end_time: '2026-06-22T11:00:00',
-    item_code: 'IMK-10235',
-    item_name: 'A4 무선 레이저프린터',
-    model_name: 'SL-M2030',
-    maker_name: 'HP',
-  },
-  {
-    session_id: 's-006',
-    session_status: '협상중',
-    qt_type: '재견적',
-    qt_number: 'QT-2026-000106',
-    qt_end_time: '2026-06-16T20:00:00',
-    item_code: 'IMK-10236',
-    item_name: '회의실 대형 디스플레이 65인치',
-    model_name: 'QM65R',
-    maker_name: '삼성전자',
-  },
-  {
-    session_id: 's-007',
-    session_status: '협상생성',
-    qt_type: '재협상',
-    qt_number: 'QT-2026-000107',
-    qt_end_time: '2026-06-25T17:00:00',
-    item_code: 'IMK-10237',
-    item_name: '인체공학 사무용 의자',
-    model_name: 'ERGO-700',
-    maker_name: '시디즈',
-  },
-  {
-    session_id: 's-008',
-    session_status: '협상완료',
-    qt_type: '재견적',
-    qt_number: 'QT-2026-000108',
-    qt_end_time: '2026-06-21T10:30:00',
-    item_code: 'IMK-10238',
-    item_name: '네트워크 스위치 24포트',
-    model_name: 'SG350-28',
-    maker_name: '시스코',
-  },
-  {
-    session_id: 's-009',
-    session_status: '미참여',
-    qt_type: '재협상',
-    qt_number: 'QT-2026-000109',
-    qt_end_time: '2026-06-23T14:00:00',
-    item_code: 'IMK-10239',
-    item_name: '외장 SSD 2TB',
-    model_name: 'T7-Shield-2T',
-    maker_name: '삼성전자',
-  },
-  {
-    session_id: 's-010',
-    session_status: '협상중',
-    qt_type: '재견적',
-    qt_number: 'QT-2026-000110',
-    qt_end_time: '2026-06-24T16:20:00',
-    item_code: 'IMK-10240',
-    item_name: '화상회의용 웹캠',
-    model_name: 'BRIO-4K',
-    maker_name: '로지텍',
-  },
-]