From 1ccc3382d9c6c0233845949c196239cc192a5014 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Fri, 10 Jul 2026 21:00:33 -0700
Subject: [PATCH] feat(fallback-generalizations): widen adaptive-thinking gate
 to any claude family at major 5+

---
 ...odel_prices_and_context_window_backup.json |  4 +--
 model_prices_and_context_window.json          |  4 +--
 .../test_fallback_generalizations.py          | 29 ++++++++++++++++---
 .../anthropic/test_anthropic_common_utils.py  | 23 ++++++++-------
 4 files changed, 42 insertions(+), 18 deletions(-)

diff --git a/litellm/model_prices_and_context_window_backup.json b/litellm/model_prices_and_context_window_backup.json
index c483b3288e2..868ba5c43e3 100644
--- a/litellm/model_prices_and_context_window_backup.json
+++ b/litellm/model_prices_and_context_window_backup.json
@@ -45088,8 +45088,8 @@
             },
             {
                 "name": "claude-adaptive-thinking",
-                "pattern": "(?:opus|sonnet|haiku)[-._](?:4[-._](?:[6-9]|[1-9]\\d)(?!\\d)|(?:[5-9]|[1-9]\\d{1,})[-._]\\d{1,2}(?!\\d))",
-                "description": "Claude opus/sonnet/haiku at version 4.6 or higher: 4.6 through 4.99, then any 5.x, 6.x or later major. The minor is capped at two digits so an 8-digit date suffix such as claude-opus-4-20250514 is never read as a >= 4.6 minor. Turns on adaptive thinking for new versions with no code change.",
+                "pattern": "(?:opus|sonnet|haiku)[-._](?:4[-._](?:[6-9]|[1-9]\\d)(?!\\d)|(?:[5-9]|[1-9]\\d{1,})[-._]\\d{1,2}(?!\\d))|claude-[a-z]+-(?:[5-9]|[1-9]\\d)(?!\\d)(?:[-._]\\d{1,2}(?!\\d))?",
+                "description": "Claude opus/sonnet/haiku at version 4.6 or higher (4.6 through 4.99, then any later major-minor), plus any claude-<family>- id at major version 5 or higher, bare major or major-minor, so a new family shaped like claude-fable-5 is covered by the same gate as the core families. 4.x coverage stays limited to opus/sonnet/haiku. The minor is capped at two digits so an 8-digit date suffix such as claude-opus-4-20250514 is never read as a >= 4.6 minor. Turns on adaptive thinking for new versions and new families with no code change.",
                 "model_info": {
                     "supports_adaptive_thinking": true
                 }
diff --git a/model_prices_and_context_window.json b/model_prices_and_context_window.json
index ee0b1193990..37ce3d270c8 100644
--- a/model_prices_and_context_window.json
+++ b/model_prices_and_context_window.json
@@ -45321,8 +45321,8 @@
             },
             {
                 "name": "claude-adaptive-thinking",
-                "pattern": "(?:opus|sonnet|haiku)[-._](?:4[-._](?:[6-9]|[1-9]\\d)(?!\\d)|(?:[5-9]|[1-9]\\d{1,})[-._]\\d{1,2}(?!\\d))",
-                "description": "Claude opus/sonnet/haiku at version 4.6 or higher: 4.6 through 4.99, then any 5.x, 6.x or later major. The minor is capped at two digits so an 8-digit date suffix such as claude-opus-4-20250514 is never read as a >= 4.6 minor. Turns on adaptive thinking for new versions with no code change.",
+                "pattern": "(?:opus|sonnet|haiku)[-._](?:4[-._](?:[6-9]|[1-9]\\d)(?!\\d)|(?:[5-9]|[1-9]\\d{1,})[-._]\\d{1,2}(?!\\d))|claude-[a-z]+-(?:[5-9]|[1-9]\\d)(?!\\d)(?:[-._]\\d{1,2}(?!\\d))?",
+                "description": "Claude opus/sonnet/haiku at version 4.6 or higher (4.6 through 4.99, then any later major-minor), plus any claude-<family>- id at major version 5 or higher, bare major or major-minor, so a new family shaped like claude-fable-5 is covered by the same gate as the core families. 4.x coverage stays limited to opus/sonnet/haiku. The minor is capped at two digits so an 8-digit date suffix such as claude-opus-4-20250514 is never read as a >= 4.6 minor. Turns on adaptive thinking for new versions and new families with no code change.",
                 "model_info": {
                     "supports_adaptive_thinking": true
                 }
diff --git a/tests/test_litellm/litellm_core_utils/test_fallback_generalizations.py b/tests/test_litellm/litellm_core_utils/test_fallback_generalizations.py
index b911a46443c..e4407b547cc 100644
--- a/tests/test_litellm/litellm_core_utils/test_fallback_generalizations.py
+++ b/tests/test_litellm/litellm_core_utils/test_fallback_generalizations.py
@@ -343,14 +343,35 @@ def test_shipped_version_boundaries(shipped_cost_map, model, provider, adaptive,
     assert info.get("supports_mid_conversation_system") is mid_conversation, model
 
 
-def test_shipped_mid_conversation_rule_covers_new_families_like_fable(shipped_cost_map):
-    """The 4.8+ mid-conversation gate accepts bare 5+ majors, so a new family shaped
-    like claude-fable-5 is covered. The adaptive rule keeps its opus/sonnet/haiku
-    family list, so a fable-shaped id gets no adaptive flag from the rules."""
+def test_shipped_rules_cover_new_families_like_fable_at_5_plus(shipped_cost_map):
+    """Both version gates accept any claude-<family>- id at major 5 or higher, bare
+    major or major-minor, so a new family shaped like claude-fable-5 gets adaptive
+    thinking and mid-conversation system support without a cost-map entry."""
     model = "claude-fable-5-1"
     assert model not in litellm.model_cost
     info = litellm.get_model_info(model, custom_llm_provider="anthropic")
     assert info["supports_mid_conversation_system"] is True
+    assert info["supports_adaptive_thinking"] is True
+    assert info["supports_function_calling"] is True
+
+
+def test_shipped_rules_flag_bare_5_plus_majors_of_any_family(shipped_cost_map):
+    """A bare 5+ major with no minor gets both flags at the rule level; the mapped
+    claude-fable-5 entry itself still resolves from the cost map, so this pins the
+    pattern via the capability union rather than get_model_info."""
+    matched = match_capability_generalizations("claude-fable-5")
+    assert matched is not None
+    assert matched["supports_adaptive_thinking"] is True
+    assert matched["supports_mid_conversation_system"] is True
+
+
+def test_shipped_adaptive_rule_keeps_4x_coverage_to_core_families(shipped_cost_map):
+    """The family-agnostic adaptive branch starts at major 5; a non-core family at
+    4.x gets the 4.8+ mid-conversation flag and baseline caps but never adaptive."""
+    model = "claude-newfam-4-9"
+    assert model not in litellm.model_cost
+    info = litellm.get_model_info(model, custom_llm_provider="anthropic")
+    assert info["supports_mid_conversation_system"] is True
     assert info.get("supports_adaptive_thinking") is None
     assert info["supports_function_calling"] is True
 
diff --git a/tests/test_litellm/llms/anthropic/test_anthropic_common_utils.py b/tests/test_litellm/llms/anthropic/test_anthropic_common_utils.py
index f7a234c8ae8..316f0d6ddf7 100644
--- a/tests/test_litellm/llms/anthropic/test_anthropic_common_utils.py
+++ b/tests/test_litellm/llms/anthropic/test_anthropic_common_utils.py
@@ -1649,17 +1649,18 @@ class TestClaudeOpus48AdaptiveThinking:
     @pytest.mark.parametrize(
         "model",
         [
-            "us.anthropic.claude-fable-5-preview",
-            "claude-fable-5-preview",
+            "us.anthropic.claude-fable-preview",
+            "claude-fable-preview",
         ],
     )
     def test_unmapped_aliases_without_parseable_version_stay_non_adaptive(
         self, local_model_cost_map, model
     ):
         """An alias absent from the map, not matched by any ``fallback_generalizations``
-        rule, and without a parseable opus/sonnet/haiku >= 4.6 family version stays
-        non-adaptive. ``fable`` is outside the version-rule family set, so neither the
-        cost map nor the declarative rule marks it adaptive."""
+        rule, and without any parseable family version stays non-adaptive. ``fable``
+        without a major version matches neither the core-family 4.6+ gate nor the
+        family-agnostic 5+ gate, so neither the cost map nor the declarative rule marks
+        it adaptive."""
         import litellm
         from litellm.llms.anthropic.common_utils import AnthropicModelInfo
 
@@ -1676,16 +1677,18 @@ class TestClaudeOpus48AdaptiveThinking:
             "claude-opus-5-0",
             "claude-opus-4-10",
             "claude-opus-4-8-some-future-suffix",
+            "claude-fable-5-preview",
+            "us.anthropic.claude-fable-5-preview",
         ],
     )
     def test_adaptive_thinking_version_fallback_for_unmapped_high_versions(
         self, local_model_cost_map, model
     ):
-        """Provider-prefixed or suffixed Claude names that resolve to no mapped entry and
-        are not matched by the anchored ``anthropic-claude`` pricing rule still resolve to
-        adaptive when their opus/sonnet/haiku family version is >= 4.6. The version gate is
-        the declarative ``anthropic-claude-adaptive-thinking`` rule, so 5.x, 6.x and any
-        later family are covered with no code change."""
+        """Provider-prefixed or suffixed Claude names that resolve to no mapped entry
+        still resolve to adaptive when their opus/sonnet/haiku family version is >= 4.6
+        or any family's major version is >= 5. The version gate is the declarative
+        ``claude-adaptive-thinking`` rule, so 5.x, 6.x and any later family are covered
+        with no code change."""
         import litellm
         from litellm.llms.anthropic.common_utils import AnthropicModelInfo