diff --git a/fe-admin/src/components/pe/PeDetailTabs.tsx b/fe-admin/src/components/pe/PeDetailTabs.tsx
index b642435..59b5424 100644
--- a/fe-admin/src/components/pe/PeDetailTabs.tsx
+++ b/fe-admin/src/components/pe/PeDetailTabs.tsx
@@ -2,7 +2,7 @@
 // NCC + Hạng mục + Báo giá stack vertically trong 1 màn hình.
 // Duyệt history + Lịch sử thay đổi → moved to Panel 3 (xem PeWorkflowPanel
 // → PeApprovalsSection + PeHistorySection).
-import { useEffect, useRef, useState } from 'react'
+import { useEffect, useMemo, useRef, useState } from 'react'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { useNavigate } from 'react-router-dom'
 import { toast } from 'sonner'
@@ -30,6 +30,7 @@ import {
   PurchaseEvaluationTypeLabel,
   getPeDisplayStatus,
   isEditablePhase,
+  type PeApproval,
   type PeAttachment,
   type PeChangelog,
   type PeDepartmentOpinion,
@@ -2013,10 +2014,61 @@ function decisionBadge(decision: number, toPhase: number): { label: string; cls:
 }
 
 function ApprovalsTab({ ev }: { ev: PeDetailBundle }) {
-  if (ev.approvals.length === 0) return <p className="text-sm text-slate-500">Chưa có bước duyệt nào.</p>
+  // Plan AC2 S25 — FE merge view: fetch changelogs + reconstruct synthetic
+  // Reject rows từ pre-Plan AC historical data (PE cũ deploy trước 2026-05-19
+  // KHÔNG có Approval row cho Reject vì BE cũ chỉ log Changelog). Merge approvals
+  // + synthetic + dedupe timestamp 5s bucket cùng approverUserId.
+  const changelogs = useQuery({
+    queryKey: ['pe-changelog', ev.id],
+    queryFn: async () => (await api.get<PeChangelog[]>(`/purchase-evaluations/${ev.id}/changelogs`)).data,
+  })
+
+  const merged = useMemo(() => {
+    const phaseEnumMap: Record<string, number> = {
+      DangSoanThao: 1, ChoDuyet: 10, DaDuyet: 20, TraLai: 98, TuChoi: 99,
+    }
+    const PE_ENTITY_WORKFLOW = 5
+    const syntheticRejects: PeApproval[] = (changelogs.data ?? [])
+      .filter(c => {
+        if (c.entityType !== PE_ENTITY_WORKFLOW) return false
+        if (c.summary?.includes('→ TraLai') || c.summary?.includes('→ TuChoi')) return true
+        // 3 mode (OneLevel/OneStep/Assignee) giữ ChoDuyet → distinguish qua ContextNote keywords
+        const note = c.contextNote ?? ''
+        return note.includes('Trả về') || note.includes('không lùi được')
+      })
+      .map<PeApproval>(c => {
+        const m = c.summary?.match(/Chuyển phase (\w+) → (\w+)/)
+        const fromPhase = m ? (phaseEnumMap[m[1]] ?? 10) : 10
+        const toPhase = m ? (phaseEnumMap[m[2]] ?? 10) : 10
+        return {
+          id: `syn-${c.id}`,
+          fromPhase,
+          toPhase,
+          approverUserId: c.userId ?? null,
+          approverName: c.userName ?? null,
+          decision: 2,
+          comment: c.contextNote ?? c.summary ?? null,
+          approvedAt: c.createdAt,
+        }
+      })
+
+    const realRejectKeys = new Set(
+      ev.approvals
+        .filter(a => a.decision === 2)
+        .map(a => `${a.approverUserId ?? ''}-${Math.floor(new Date(a.approvedAt).getTime() / 5000)}`),
+    )
+    const dedupedSynthetic = syntheticRejects.filter(s =>
+      !realRejectKeys.has(`${s.approverUserId ?? ''}-${Math.floor(new Date(s.approvedAt).getTime() / 5000)}`),
+    )
+
+    return [...ev.approvals, ...dedupedSynthetic]
+      .sort((a, b) => new Date(a.approvedAt).getTime() - new Date(b.approvedAt).getTime())
+  }, [ev.approvals, changelogs.data])
+
+  if (merged.length === 0) return <p className="text-sm text-slate-500">Chưa có bước duyệt nào.</p>
   return (
     <ol className="space-y-2">
-      {ev.approvals.map(a => {
+      {merged.map(a => {
         const dec = decisionBadge(a.decision, a.toPhase)
         return (
           <li key={a.id} className="rounded border border-slate-200 bg-white p-3 text-sm">
diff --git a/fe-user/src/components/pe/PeDetailTabs.tsx b/fe-user/src/components/pe/PeDetailTabs.tsx
index 84a22cf..37c4f19 100644
--- a/fe-user/src/components/pe/PeDetailTabs.tsx
+++ b/fe-user/src/components/pe/PeDetailTabs.tsx
@@ -2,7 +2,7 @@
 // NCC + Hạng mục + Báo giá stack vertically trong 1 màn hình.
 // Duyệt history + Lịch sử thay đổi → moved to Panel 3 (xem PeWorkflowPanel
 // → PeApprovalsSection + PeHistorySection).
-import { useEffect, useRef, useState } from 'react'
+import { useEffect, useMemo, useRef, useState } from 'react'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { useNavigate } from 'react-router-dom'
 import { toast } from 'sonner'
@@ -30,6 +30,7 @@ import {
   PurchaseEvaluationTypeLabel,
   getPeDisplayStatus,
   isEditablePhase,
+  type PeApproval,
   type PeAttachment,
   type PeChangelog,
   type PeDepartmentOpinion,
@@ -2007,10 +2008,61 @@ function decisionBadge(decision: number, toPhase: number): { label: string; cls:
 }
 
 function ApprovalsTab({ ev }: { ev: PeDetailBundle }) {
-  if (ev.approvals.length === 0) return <p className="text-sm text-slate-500">Chưa có bước duyệt nào.</p>
+  // Plan AC2 S25 — FE merge view: fetch changelogs + reconstruct synthetic
+  // Reject rows từ pre-Plan AC historical data (PE cũ deploy trước 2026-05-19
+  // KHÔNG có Approval row cho Reject vì BE cũ chỉ log Changelog). Merge approvals
+  // + synthetic + dedupe timestamp 5s bucket cùng approverUserId.
+  const changelogs = useQuery({
+    queryKey: ['pe-changelog', ev.id],
+    queryFn: async () => (await api.get<PeChangelog[]>(`/purchase-evaluations/${ev.id}/changelogs`)).data,
+  })
+
+  const merged = useMemo(() => {
+    const phaseEnumMap: Record<string, number> = {
+      DangSoanThao: 1, ChoDuyet: 10, DaDuyet: 20, TraLai: 98, TuChoi: 99,
+    }
+    const PE_ENTITY_WORKFLOW = 5
+    const syntheticRejects: PeApproval[] = (changelogs.data ?? [])
+      .filter(c => {
+        if (c.entityType !== PE_ENTITY_WORKFLOW) return false
+        if (c.summary?.includes('→ TraLai') || c.summary?.includes('→ TuChoi')) return true
+        // 3 mode (OneLevel/OneStep/Assignee) giữ ChoDuyet → distinguish qua ContextNote keywords
+        const note = c.contextNote ?? ''
+        return note.includes('Trả về') || note.includes('không lùi được')
+      })
+      .map<PeApproval>(c => {
+        const m = c.summary?.match(/Chuyển phase (\w+) → (\w+)/)
+        const fromPhase = m ? (phaseEnumMap[m[1]] ?? 10) : 10
+        const toPhase = m ? (phaseEnumMap[m[2]] ?? 10) : 10
+        return {
+          id: `syn-${c.id}`,
+          fromPhase,
+          toPhase,
+          approverUserId: c.userId ?? null,
+          approverName: c.userName ?? null,
+          decision: 2,
+          comment: c.contextNote ?? c.summary ?? null,
+          approvedAt: c.createdAt,
+        }
+      })
+
+    const realRejectKeys = new Set(
+      ev.approvals
+        .filter(a => a.decision === 2)
+        .map(a => `${a.approverUserId ?? ''}-${Math.floor(new Date(a.approvedAt).getTime() / 5000)}`),
+    )
+    const dedupedSynthetic = syntheticRejects.filter(s =>
+      !realRejectKeys.has(`${s.approverUserId ?? ''}-${Math.floor(new Date(s.approvedAt).getTime() / 5000)}`),
+    )
+
+    return [...ev.approvals, ...dedupedSynthetic]
+      .sort((a, b) => new Date(a.approvedAt).getTime() - new Date(b.approvedAt).getTime())
+  }, [ev.approvals, changelogs.data])
+
+  if (merged.length === 0) return <p className="text-sm text-slate-500">Chưa có bước duyệt nào.</p>
   return (
     <ol className="space-y-2">
-      {ev.approvals.map(a => {
+      {merged.map(a => {
         const dec = decisionBadge(a.decision, a.toPhase)
         return (
           <li key={a.id} className="rounded border border-slate-200 bg-white p-3 text-sm">