diff --git a/.agents/skills/lib_py/agents/adapters/codex.py b/.agents/skills/lib_py/agents/adapters/codex.py
index 4b4fa53..d330550 100644
--- a/.agents/skills/lib_py/agents/adapters/codex.py
+++ b/.agents/skills/lib_py/agents/adapters/codex.py
@@ -1,6 +1,6 @@
-import os, json, glob, sqlite3, subprocess
+import os, json, glob, shutil, sqlite3, subprocess
 from typing import Optional, Any, List
-from lib_py.agents.base import BaseAgentAdapter, DiscoveryContext, _ro_connect, scan_names, db_rows_naming
+from lib_py.agents.base import BaseAgentAdapter, DiscoveryContext, _plausible_id, _ro_connect, scan_names, db_rows_naming
 from lib_py.verify_session import workspace_key
 
 class CodexAgentAdapter(BaseAgentAdapter):
@@ -131,6 +131,22 @@ class CodexAgentAdapter(BaseAgentAdapter):
         except Exception:
             return False
 
+    def _purge_tui_thread_capability(self, uuid: str, ctx: DiscoveryContext, purged: List[str]) -> None:
+        if not _plausible_id(uuid):
+            return
+        cap = os.path.join(self._codex_home(ctx), "tui-thread-reference-capabilities", uuid)
+        if not os.path.lexists(cap):
+            return
+        try:
+            if os.path.isdir(cap) and not os.path.islink(cap):
+                shutil.rmtree(cap)
+            else:
+                os.unlink(cap)
+            if not os.path.lexists(cap):
+                purged.append(cap)
+        except Exception:
+            pass
+
     def purge_artifacts(self, uuid: str, ctx: DiscoveryContext) -> List[str]:
         purged = []
         path = self._find_rollout(uuid, ctx)
@@ -140,12 +156,16 @@ class CodexAgentAdapter(BaseAgentAdapter):
             if res.returncode == 0:
                 if path:
                     purged.append(path)
+                self._purge_tui_thread_capability(uuid, ctx, purged)
                 return purged
         except Exception:
             pass
         if path and os.path.exists(path):
-            os.remove(path)
-            purged.append(path)
+            try:
+                os.remove(path)
+                purged.append(path)
+            except Exception:
+                pass
         db = self._state_db(ctx)
         if db and os.path.exists(db):
             try:
@@ -156,6 +176,7 @@ class CodexAgentAdapter(BaseAgentAdapter):
                 purged.append(f"state db row for thread: {uuid}")
             except Exception:
                 pass
+        self._purge_tui_thread_capability(uuid, ctx, purged)
         return purged
 
     def residual_artifacts(self, uuid: str, ctx: DiscoveryContext) -> List[str]:
diff --git a/tests/test_issue78_hints_codex.py b/tests/test_issue78_hints_codex.py
index a19d12f..efce778 100644
--- a/tests/test_issue78_hints_codex.py
+++ b/tests/test_issue78_hints_codex.py
@@ -249,3 +249,76 @@ def test_stop_purge_refusal_prints_holders(mam_sandbox, mock_herdr, monkeypatch)
     finally:
         holder.kill()
         holder.wait()
+
+
+@pytest.mark.parametrize("delete_ok", [True, False], ids=["delete_ok", "delete_fails"])
+def test_codex_purge_removes_tui_thread_capability(tmp_path, monkeypatch, delete_ok):
+    home = tmp_path / "home"
+    codex_home = tmp_path / "codex-home"
+    ws = tmp_path / "ws"
+    bindir = tmp_path / "bin"
+    for d in (home, codex_home, ws, bindir):
+        d.mkdir(parents=True, exist_ok=True)
+
+    conv = str(uuidlib.uuid4())
+    other = str(uuidlib.uuid4())
+
+    rollout = codex_home / "sessions" / "2026" / "10" / "28" / f"rollout-2026-10-28T00-00-00-{conv}.jsonl"
+    rollout.parent.mkdir(parents=True, exist_ok=True)
+    rollout.write_text(json.dumps({"payload": {"id": conv, "cwd": str(ws)}}) + "\n", encoding="utf-8")
+
+    cap_dir = codex_home / "tui-thread-reference-capabilities"
+    cap_dir.mkdir(parents=True, exist_ok=True)
+    cap_mine = cap_dir / conv
+    cap_other = cap_dir / other
+    cap_mine.write_text("cap-mine", encoding="utf-8")
+    cap_other.write_text("cap-other", encoding="utf-8")
+
+    state_db = codex_home / "state_5.sqlite"
+    conn = sqlite3.connect(str(state_db))
+    conn.execute("CREATE TABLE threads (id TEXT PRIMARY KEY, rollout_path TEXT, cwd TEXT)")
+    conn.execute("INSERT INTO threads VALUES (?, ?, ?)", (conv, str(rollout), str(ws)))
+    conn.execute("INSERT INTO threads VALUES (?, ?, ?)", (other, "", str(ws)))
+    conn.commit()
+    conn.close()
+
+    fake_codex = bindir / "codex"
+    if delete_ok:
+        # Simulate `codex delete <uuid> --force` removing rollout + DB row, leaving tui-thread-reference-capabilities.
+        fake_codex.write_text(
+            f"#!{sys.executable}\n"
+            "import os, sqlite3, sys\n"
+            "if len(sys.argv) >= 3 and sys.argv[1] == 'delete':\n"
+            f"    p = {str(rollout)!r}\n"
+            "    if os.path.exists(p):\n"
+            "        os.remove(p)\n"
+            f"    conn = sqlite3.connect({str(state_db)!r})\n"
+            "    conn.execute('DELETE FROM threads WHERE id=?', (sys.argv[2],))\n"
+            "    conn.commit()\n"
+            "    conn.close()\n"
+            "    sys.exit(0)\n"
+            "sys.exit(1)\n",
+            encoding="utf-8",
+        )
+    else:
+        fake_codex.write_text("#!/bin/sh\nexit 1\n", encoding="utf-8")
+    fake_codex.chmod(0o755)
+
+    monkeypatch.setenv("HOME", str(home))
+    monkeypatch.setenv("HOME_DIR", str(home))
+    monkeypatch.setenv("CODEX_HOME", str(codex_home))
+    monkeypatch.setenv("PATH", f"{bindir}:{os.environ.get('PATH', '')}")
+
+    adapter = get_adapter("codex")
+    ctx = DiscoveryContext(workspace=str(ws), agent_name="codex", home_dir=str(home))
+    assert str(cap_mine) in adapter.residual_artifacts(conv, ctx)
+
+    purged = adapter.purge_artifacts(conv, ctx)
+
+    assert str(cap_mine) in purged
+    assert not cap_mine.exists()
+    assert cap_other.exists()
+    assert not rollout.exists()
+    assert adapter.residual_artifacts(conv, ctx) == []
+    assert str(cap_other) in adapter.residual_artifacts(other, ctx)
+