diff --git a/pyproject.toml b/pyproject.toml
index d80a885..940034c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ratatoskr"
-version = "0.21.16"
+version = "0.21.17"
 description = "Worldtree Conversation API debug console (web + headless CLI) — multi-pane observability"
 readme = "README.md"
 requires-python = ">=3.12"
diff --git a/src/ratatoskr/cli.py b/src/ratatoskr/cli.py
index 1f5e35a..0c38fb3 100644
--- a/src/ratatoskr/cli.py
+++ b/src/ratatoskr/cli.py
@@ -750,7 +750,11 @@ def _format_whoami(me: Mapping[str, Any], caps: Mapping[str, Any]) -> str:
     lines = ["identity:"]
     lines.append(f"  user_id: {me.get('user_id', '?')}")
     lines.append(f"  tier: {me.get('tier', '?')}")
-    lines.append(f"  scopes: {', '.join(me.get('scopes', [])) or '(none)'}")
+    # Open-world read: `scopes` may be absent, present-null, or carry non-strings —
+    # `or []` + str() degrades all three (a present-null `.get('scopes', [])` returns
+    # None, not the default), matching the `allowed_roles` hardening below (heid-code-
+    # review slice-5: the contract names this function the degrade-not-crash exemplar).
+    lines.append(f"  scopes: {', '.join(str(s) for s in (me.get('scopes') or [])) or '(none)'}")
     for k in ("display_name", "key_id", "key_label"):
         if k in me:
             lines.append(f"  {k}: {me[k]}")
@@ -828,10 +832,16 @@ async def _characters_probe(args: ParsedArgs) -> int:
         client = wt.build_client(args.server_url, api_key=args.api_key, transport=transport)
         try:
             models = await wt.list_character_models(client)
-            # Open-world read: `items` may be absent OR explicit-null — `or []` degrades
-            # both to empty (mirrors the slice-4 `_format_whoami` hardening), never a
-            # `join(None)` crash.
-            names = ", ".join(m.get("name", "?") for m in (models.get("items") or []))
+            # Open-world read: `items` may be absent/null (`or []`) AND each entry may be
+            # a non-mapping (`[None]` / `["x"]`) or carry a non-string `name` — guard the
+            # item is a dict and coerce `name` to str so a malformed catalog degrades
+            # rather than crashing (heid-code-review slice-5; element-level completion of
+            # the list-level `or []` guard).
+            names = ", ".join(
+                str(m.get("name", "?"))
+                for m in (models.get("items") or [])
+                if isinstance(m, dict)
+            )
             sys.stdout.write(f"character models: {names or '(none)'}\n")
             created = await wt.create_character(
                 client,
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 8c4668d..075a06b 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -1879,6 +1879,25 @@ class TestWhoami:
         assert rc == 20
         assert "[session_api_failed]" in capsys.readouterr().err
 
+    @respx.mock
+    def test_whoami_tolerates_null_and_nonstring_scopes(
+        self, capsys: pytest.CaptureFixture[str]
+    ) -> None:
+        """scopes present-null / non-string → renders '(none)' or str-coerced, never a
+        `join(None)` TypeError (heid-code-review slice-5: `_format_whoami` is the
+        contract's degrade-not-crash exemplar; `allowed_roles` was hardened, `scopes`
+        was not)."""
+        # scopes: null (present, not absent) → `.get('scopes', [])` would return None.
+        respx.get("https://w.example/me").mock(
+            return_value=httpx.Response(200, json={"user_id": "u", "scopes": None, "tier": "user"})
+        )
+        respx.get("https://w.example/capabilities").mock(
+            return_value=httpx.Response(200, json={"ephemeral_templates": {}})
+        )
+        rc = main(["--whoami", "--api-key", "k", "--server", "https://w.example"])
+        assert rc == 0
+        assert "scopes: (none)" in capsys.readouterr().out
+
 
 class TestTier2Probes:
     """--characters + --set-persona-pad one-shot probes (Tier-2: #161 + persona_state-write)."""
@@ -1923,6 +1942,32 @@ class TestTier2Probes:
         assert "deleted: char_z" in out
         assert del_route.call_count == 1  # lifecycle cleaned up
 
+    @respx.mock
+    def test_characters_probe_tolerates_malformed_models(
+        self, capsys: pytest.CaptureFixture[str]
+    ) -> None:
+        """models catalog with non-mapping / non-string-name items → degrades (no
+        AttributeError/TypeError), lifecycle still proceeds (heid-code-review slice-5:
+        element-level completion of the list-level `or []` guard)."""
+        respx.get("https://w.example/models/available-for-characters").mock(
+            return_value=httpx.Response(
+                200, json={"items": [None, "x", {"name": 123}, {"name": "ok"}]}
+            )
+        )
+        respx.post("https://w.example/characters").mock(
+            return_value=httpx.Response(201, json={"character_id": "c1", "ttl_expires_at": "t"})
+        )
+        respx.get("https://w.example/characters/c1/state").mock(
+            return_value=httpx.Response(200, json={"pad": [0.0, 0.0, 0.0]})
+        )
+        respx.delete("https://w.example/characters/c1").mock(return_value=httpx.Response(204))
+        rc = main(["--characters", "--api-key", "k", "--server", "https://w.example"])
+        assert rc == 0
+        out = capsys.readouterr().out
+        # non-mappings dropped; {"name":123}→"123", {"name":"ok"}→"ok" — no crash.
+        assert "character models: 123, ok" in out
+        assert "created: c1" in out
+
     @respx.mock
     def test_characters_probe_create_missing_id_aborts(
         self, capsys: pytest.CaptureFixture[str]
diff --git a/uv.lock b/uv.lock
index 3ae38c6..68ac1f4 100644
--- a/uv.lock
+++ b/uv.lock
@@ -472,7 +472,7 @@ wheels = [
 
 [[package]]
 name = "ratatoskr"
-version = "0.21.16"
+version = "0.21.17"
 source = { editable = "." }
 dependencies = [
     { name = "httpx" },