diff --git a/Releases/v4.0.3/.claude/hooks/PostCompact.hook.ts b/Releases/v4.0.3/.claude/hooks/PostCompact.hook.ts
new file mode 100644
index 000000000..cb92701ed
--- /dev/null
+++ b/Releases/v4.0.3/.claude/hooks/PostCompact.hook.ts
@@ -0,0 +1,125 @@
+#!/usr/bin/env bun
+/**
+ * PostCompact.hook.ts - Re-inject critical PAI state after context compaction
+ *
+ * TRIGGER: PostCompact (fires after Claude Code compacts conversation context)
+ *
+ * PURPOSE:
+ * Context compaction can wipe dynamic state that LoadContext injected at session
+ * start. This hook re-injects the most critical pieces so the model doesn't
+ * lose track of active work, learning signals, or relationship context.
+ *
+ * OUTPUT:
+ * - stdout: <system-reminder> with compact state recovery
+ * - exit(0): Normal completion
+ *
+ * PERFORMANCE:
+ * - <50ms (reads small cached files only)
+ */
+
+import { readFileSync, existsSync, readdirSync } from 'fs';
+import { join } from 'path';
+import { getPaiDir } from './lib/paths';
+
+const paiDir = getPaiDir();
+
+function loadJSON(path: string): any {
+  try {
+    if (existsSync(path)) return JSON.parse(readFileSync(path, 'utf-8'));
+  } catch {}
+  return null;
+}
+
+// Build compact state recovery
+const parts: string[] = [];
+
+// 1. Active work sessions (from work.json — lightweight)
+const workJson = loadJSON(join(paiDir, 'MEMORY', 'STATE', 'work.json'));
+if (workJson?.sessions) {
+  const now = Date.now();
+  const cutoff = 48 * 60 * 60 * 1000;
+  const recent = Object.entries(workJson.sessions)
+    .filter(([_, s]: [string, any]) => {
+      const ts = new Date(s.updated || s.started || 0).getTime();
+      return now - ts < cutoff;
+    })
+    .slice(0, 8);
+
+  if (recent.length > 0) {
+    parts.push('## Active Work (last 48h)');
+    for (const [slug, s] of recent as [string, any][]) {
+      const title = s.title || slug;
+      const status = s.phase || s.status || '?';
+      const progress = s.progress || '?';
+      parts.push(`- ${title} | ${status} | ${progress}`);
+    }
+  }
+}
+
+// 2. Signal trends (from learning-cache.sh if it exists)
+const cachePath = join(paiDir, 'MEMORY', 'STATE', 'learning-cache.sh');
+if (existsSync(cachePath)) {
+  try {
+    const cache = readFileSync(cachePath, 'utf-8');
+    const weekAvg = cache.match(/week_avg='([^']+)'/)?.[1];
+    const trend = cache.match(/trend='([^']+)'/)?.[1];
+    if (weekAvg && trend) {
+      parts.push(`\n## Learning Signals\nWeek avg: ${weekAvg}/10 | Trend: ${trend}`);
+    }
+  } catch {}
+}
+
+// 3. Key feedback rules (these are the ones that keep getting violated after compaction)
+parts.push(`
+## Key Rules (post-compaction reminder)
+- Consolidated scripts only — no individual commands for multi-step work
+- Capability selection is binding — must invoke via tool, not text-only
+- Security tasks require Security skill invocation
+- Verify before asserting — never claim "done" without evidence`);
+
+// 4. Algorithm state recovery (from most recent PRD)
+try {
+  const workDir = join(paiDir, 'MEMORY', 'WORK');
+  if (existsSync(workDir)) {
+    const dirs = readdirSync(workDir).sort();
+    const latest = dirs[dirs.length - 1];
+    if (latest) {
+      const prdPath = join(workDir, latest, 'PRD.md');
+      if (existsSync(prdPath)) {
+        const prd = readFileSync(prdPath, 'utf-8');
+        const fm = prd.match(/^---\n([\s\S]*?)\n---/);
+        if (fm) {
+          const yaml = fm[1];
+          const phase = yaml.match(/^phase:\s*(.+)$/m)?.[1]?.trim();
+          const progress = yaml.match(/^progress:\s*(.+)$/m)?.[1]?.trim();
+          const effort = yaml.match(/^effort:\s*(.+)$/m)?.[1]?.trim();
+          const task = yaml.match(/^task:\s*(.+)$/m)?.[1]?.trim();
+          const slug = yaml.match(/^slug:\s*(.+)$/m)?.[1]?.trim();
+
+          if (phase && phase !== 'complete') {
+            const lines: string[] = [`\n## Algorithm State Recovery`];
+            lines.push(`- **Task:** ${task || slug || latest}`);
+            lines.push(`- **Phase:** ${phase} | **Progress:** ${progress || '?'} | **Effort:** ${effort || '?'}`);
+            lines.push(`- **PRD:** MEMORY/WORK/${latest}/PRD.md`);
+
+            // Extract ISC criteria
+            const criteria = prd.match(/^- \[[ x]\].+$/gm);
+            if (criteria && criteria.length > 0) {
+              lines.push('- **ISC Criteria:**');
+              for (const c of criteria) {
+                lines.push(`  ${c}`);
+              }
+            }
+
+            parts.push(lines.join('\n'));
+          }
+        }
+      }
+    }
+  }
+} catch {}
+
+if (parts.length > 0) {
+  const output = `<system-reminder>\n# PAI State Recovery (post-compaction)\n\n${parts.join('\n')}\n</system-reminder>`;
+  process.stdout.write(output);
+}
diff --git a/Releases/v4.0.3/.claude/settings.json b/Releases/v4.0.3/.claude/settings.json
index 6e69e98ae..8eb12aab8 100755
--- a/Releases/v4.0.3/.claude/settings.json
+++ b/Releases/v4.0.3/.claude/settings.json
@@ -242,6 +242,16 @@
           }
         ]
       }
+    ],
+    "PostCompact": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "${PAI_DIR}/hooks/PostCompact.hook.ts"
+          }
+        ]
+      }
     ]
   },
   "statusLine": {