fix(model_metadata): drop stale cache entries for qwen3.6-plus, grok-4-fast, grok-4.20

agent/model_metadata.py

@@ -1140,6 +1140,33 @@ def _model_name_suggests_minimax_m3(model: str) -> bool:
     return "minimax-m3" in model.lower()
 
 
+def _model_name_suggests_qwen3_6_plus(model: str) -> bool:
+    """Return True if the model name looks like a Qwen 3.6-Plus variant.
+
+    Catches ``qwen3.6-plus``, ``qwen/qwen3.6-plus``, ``dashscope/qwen3.6-plus``,
+    and similar prefixed forms.  Used as a guard against stale cache entries
+    seeded by pre-catalog builds that resolved qwen3.6-plus via the generic
+    ``qwen`` catch-all (131,072) before the ``qwen3.6-plus`` (1M) entry was
+    added to DEFAULT_CONTEXT_LENGTHS on 2026-05-17.
+    """
+    return "qwen3.6-plus" in model.lower()
+
+
+def _model_name_suggests_grok_4_fast_or_4_20(model: str) -> bool:
+    """Return True if the model name looks like a Grok 4-fast or 4.20 variant.
+
+    Catches ``grok-4-fast``, ``grok-4-fast-reasoning``,
+    ``grok-4.20-0309-reasoning``, ``grok-4.20-multi-agent-0309``, and similar
+    slugs.  Used as a guard against stale cache entries seeded before the
+    ``grok-4-fast`` (2M) and ``grok-4.20`` (2M) entries were added to
+    DEFAULT_CONTEXT_LENGTHS on 2026-04-10.  Prior to that, these slugs fell
+    through to the DEFAULT_FALLBACK_CONTEXT (256,000) or, via a custom
+    endpoint probe, could have been persisted at an even lower tier value.
+    """
+    lower = model.lower()
+    return "grok-4-fast" in lower or "grok-4.20" in lower
+
+
 def _query_local_context_length(model: str, base_url: str, api_key: str = "") -> Optional[int]:
     """Query a local server for the model's context length."""
     import httpx
@@ -1564,6 +1591,31 @@ def get_model_context_length(
                     model, base_url, f"{cached:,}",
                 )
                 _invalidate_cached_context_length(model, base_url)
+            # Invalidate stale ≤131,072 cache entries for qwen3.6-plus.  The
+            # ``qwen3.6-plus`` (1M) entry was added to DEFAULT_CONTEXT_LENGTHS on
+            # 2026-05-17; prior to that, qwen3.6-plus slugs resolved via the
+            # generic ``qwen`` catch-all (131,072) and that value was persisted.
+            # qwen3.6-plus is 1M, so any sub-262K cached value is a pre-catalog
+            # leftover — drop it and fall through to the hardcoded default.
+            elif cached <= 131_072 and _model_name_suggests_qwen3_6_plus(model):
+                logger.info(
+                    "Dropping stale qwen3.6-plus cache entry %s@%s -> %s (pre-catalog value); "
+                    "re-resolving via hardcoded defaults",
+                    model, base_url, f"{cached:,}",
+                )
+                _invalidate_cached_context_length(model, base_url)
+            # Invalidate stale ≤256,000 cache entries for grok-4-fast and grok-4.20.
+            # These 2M-context models were added to DEFAULT_CONTEXT_LENGTHS on
+            # 2026-04-10; prior to that, they fell through to the DEFAULT_FALLBACK_CONTEXT
+            # (256,000) or lower probe tiers, and that value could have been persisted.
+            # Any sub-512K cached value for these slugs is a pre-catalog leftover.
+            elif cached <= 256_000 and _model_name_suggests_grok_4_fast_or_4_20(model):
+                logger.info(
+                    "Dropping stale grok-4-fast/grok-4.20 cache entry %s@%s -> %s (pre-catalog value); "
+                    "re-resolving via hardcoded defaults",
+                    model, base_url, f"{cached:,}",
+                )
+                _invalidate_cached_context_length(model, base_url)
             # Nous Portal: the portal /v1/models endpoint is authoritative.
             # Bypass the persistent cache so step 5b can always reconcile
             # against it — this corrects pre-fix entries seeded from the

tests/agent/test_model_metadata.py

@@ -1247,3 +1247,165 @@ def test_special_chars_in_model_name(self, tmp_path):
         with patch("agent.model_metadata._get_context_cache_path", return_value=cache_file):
             save_context_length(model, url, 200000)
             assert get_cached_context_length(model, url) == 200000
+
+
+class TestQwen36PlusStaleCacheGuard:
+    """Pre-catalog builds resolved qwen3.6-plus via the generic 'qwen' catch-all
+    (131,072) and persisted it before the 'qwen3.6-plus' (1M) entry was added on
+    2026-05-17.  The step-1 cache guard must drop that stale value so the correct
+    1M entry from DEFAULT_CONTEXT_LENGTHS is used instead."""
+
+    def test_helper_catches_bare_slug(self):
+        from agent.model_metadata import _model_name_suggests_qwen3_6_plus
+        assert _model_name_suggests_qwen3_6_plus("qwen3.6-plus") is True
+        assert _model_name_suggests_qwen3_6_plus("qwen/qwen3.6-plus") is True
+        assert _model_name_suggests_qwen3_6_plus("dashscope/qwen3.6-plus") is True
+
+    def test_helper_rejects_other_qwen(self):
+        from agent.model_metadata import _model_name_suggests_qwen3_6_plus
+        assert _model_name_suggests_qwen3_6_plus("qwen3-coder-plus") is False
+        assert _model_name_suggests_qwen3_6_plus("qwen") is False
+        assert _model_name_suggests_qwen3_6_plus("qwen3.5-72b") is False
+
+    @patch("agent.models_dev.lookup_models_dev_context", return_value=None)
+    @patch("agent.model_metadata.fetch_model_metadata")
+    def test_stale_131k_cache_dropped_and_re_resolved(self, mock_fetch, _mock_mdev, tmp_path):
+        """A cached value of 131,072 (pre-catalog qwen catch-all) for qwen3.6-plus
+        must be dropped so the lookup falls through to the 1M hardcoded default
+        in DEFAULT_CONTEXT_LENGTHS."""
+        from agent.model_metadata import (
+            get_model_context_length,
+            save_context_length,
+        )
+        mock_fetch.return_value = {}
+        cache_file = tmp_path / "cache.yaml"
+        url = "https://dashscope.aliyuncs.com/compatible-mode/v1"
+        with patch("agent.model_metadata._get_context_cache_path", return_value=cache_file):
+            save_context_length("qwen3.6-plus", url, 131_072)
+            result = get_model_context_length("qwen3.6-plus", base_url=url)
+        assert result == 1_048_576
+
+    @patch("agent.models_dev.lookup_models_dev_context", return_value=None)
+    @patch("agent.model_metadata.fetch_model_metadata")
+    def test_correct_1m_cache_preserved(self, mock_fetch, _mock_mdev, tmp_path):
+        """A cached value of 1,048,576 (already correct) must not be evicted."""
+        from agent.model_metadata import (
+            get_model_context_length,
+            save_context_length,
+        )
+        mock_fetch.return_value = {}
+        cache_file = tmp_path / "cache.yaml"
+        url = "https://dashscope.aliyuncs.com/compatible-mode/v1"
+        with patch("agent.model_metadata._get_context_cache_path", return_value=cache_file):
+            save_context_length("qwen3.6-plus", url, 1_048_576)
+            result = get_model_context_length("qwen3.6-plus", base_url=url)
+        assert result == 1_048_576
+
+    @patch("agent.models_dev.lookup_models_dev_context", return_value=None)
+    @patch("agent.model_metadata.fetch_model_metadata")
+    def test_plain_qwen_256k_cache_not_clobbered(self, mock_fetch, _mock_mdev, tmp_path):
+        """A generic 'qwen' slug with a cached 131,072 must not be evicted by
+        the qwen3.6-plus guard (no false-positive widening of the guard)."""
+        from agent.model_metadata import (
+            get_model_context_length,
+            save_context_length,
+        )
+        mock_fetch.return_value = {}
+        cache_file = tmp_path / "cache.yaml"
+        url = "https://dashscope.aliyuncs.com/compatible-mode/v1"
+        with patch("agent.model_metadata._get_context_cache_path", return_value=cache_file):
+            save_context_length("qwen", url, 131_072)
+            result = get_model_context_length("qwen", base_url=url)
+        assert result == 131_072
+
+
+class TestGrokFastAndGrok420StaleCacheGuard:
+    """grok-4-fast (2M) and grok-4.20 (2M) entries were added to
+    DEFAULT_CONTEXT_LENGTHS on 2026-04-10.  Before that, these slugs had no
+    explicit entry and could be cached at DEFAULT_FALLBACK_CONTEXT (256,000) or
+    lower via a context-overflow probe.  The step-1 guard must drop those stale
+    values so the 2M default is used."""
+
+    def test_helper_catches_grok_4_fast_variants(self):
+        from agent.model_metadata import _model_name_suggests_grok_4_fast_or_4_20
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-4-fast") is True
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-4-fast-reasoning") is True
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-4-fast-non-reasoning") is True
+
+    def test_helper_catches_grok_4_20_variants(self):
+        from agent.model_metadata import _model_name_suggests_grok_4_fast_or_4_20
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-4.20-0309-reasoning") is True
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-4.20-multi-agent-0309") is True
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-4.20") is True
+
+    def test_helper_rejects_plain_grok_4(self):
+        from agent.model_metadata import _model_name_suggests_grok_4_fast_or_4_20
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-4") is False
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-4-0709") is False
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-4.3") is False
+        assert _model_name_suggests_grok_4_fast_or_4_20("grok-3") is False
+
+    @patch("agent.models_dev.lookup_models_dev_context", return_value=None)
+    @patch("agent.model_metadata.fetch_model_metadata")
+    def test_stale_256k_cache_dropped_grok_4_fast(self, mock_fetch, _mock_mdev, tmp_path):
+        """A cached 256,000 (DEFAULT_FALLBACK_CONTEXT, pre-catalog) for grok-4-fast
+        must be dropped so the 2M hardcoded default is used."""
+        from agent.model_metadata import (
+            get_model_context_length,
+            save_context_length,
+        )
+        mock_fetch.return_value = {}
+        cache_file = tmp_path / "cache.yaml"
+        url = "https://api.x.ai/v1"
+        with patch("agent.model_metadata._get_context_cache_path", return_value=cache_file):
+            save_context_length("grok-4-fast", url, 256_000)
+            result = get_model_context_length("grok-4-fast", base_url=url)
+        assert result == 2_000_000
+
+    @patch("agent.models_dev.lookup_models_dev_context", return_value=None)
+    @patch("agent.model_metadata.fetch_model_metadata")
+    def test_stale_256k_cache_dropped_grok_4_20(self, mock_fetch, _mock_mdev, tmp_path):
+        """A cached 256,000 for grok-4.20-0309-reasoning must be dropped."""
+        from agent.model_metadata import (
+            get_model_context_length,
+            save_context_length,
+        )
+        mock_fetch.return_value = {}
+        cache_file = tmp_path / "cache.yaml"
+        url = "https://api.x.ai/v1"
+        with patch("agent.model_metadata._get_context_cache_path", return_value=cache_file):
+            save_context_length("grok-4.20-0309-reasoning", url, 256_000)
+            result = get_model_context_length("grok-4.20-0309-reasoning", base_url=url)
+        assert result == 2_000_000
+
+    @patch("agent.models_dev.lookup_models_dev_context", return_value=None)
+    @patch("agent.model_metadata.fetch_model_metadata")
+    def test_correct_2m_cache_preserved(self, mock_fetch, _mock_mdev, tmp_path):
+        """A cached 2,000,000 (already correct) must not be evicted."""
+        from agent.model_metadata import (
+            get_model_context_length,
+            save_context_length,
+        )
+        mock_fetch.return_value = {}
+        cache_file = tmp_path / "cache.yaml"
+        url = "https://api.x.ai/v1"
+        with patch("agent.model_metadata._get_context_cache_path", return_value=cache_file):
+            save_context_length("grok-4-fast", url, 2_000_000)
+            result = get_model_context_length("grok-4-fast", base_url=url)
+        assert result == 2_000_000
+
+    @patch("agent.models_dev.lookup_models_dev_context", return_value=None)
+    @patch("agent.model_metadata.fetch_model_metadata")
+    def test_plain_grok_4_256k_cache_not_clobbered(self, mock_fetch, _mock_mdev, tmp_path):
+        """A plain 'grok-4' (256K is correct) cached value must not be evicted."""
+        from agent.model_metadata import (
+            get_model_context_length,
+            save_context_length,
+        )
+        mock_fetch.return_value = {}
+        cache_file = tmp_path / "cache.yaml"
+        url = "https://api.x.ai/v1"
+        with patch("agent.model_metadata._get_context_cache_path", return_value=cache_file):
+            save_context_length("grok-4", url, 256_000)
+            result = get_model_context_length("grok-4", base_url=url)
+        assert result == 256_000