fix(model-cost-map): anchor the bedrock-claude-ids routing rule to the start of the id

litellm/model_prices_and_context_window_backup.json

@@ -45051,8 +45051,8 @@
         "rules": [
             {
                 "name": "bedrock-claude-ids",
-                "pattern": "anthropic\\.claude-",
-                "description": "Any Bedrock-syntax Claude id: the dotted anthropic.claude- segment appears in bare (anthropic.claude-...), region-prefixed (us./eu./au./jp./apac.) and global.-prefixed ids, for every version. Routes these to bedrock before the bare-id Anthropic rule is consulted.",
+                "pattern": "^(?:[a-z-]+\\.)?anthropic\\.claude-",
+                "description": "A Bedrock-syntax Claude id, for every version: anthropic.claude- at the start of the name, optionally behind a single dotted geo segment (us./eu./au./jp./apac./global./us-gov.). Anchored to the start because routing rules see the raw request string and provider inference feeds the proxy's provider/* wildcard access checks: an id under an unrecognized namespace such as bedrockz/anthropic.claude-... must stay unroutable rather than resolve to bedrock and slip through a bedrock/* key. Routes to bedrock before the bare-id Anthropic rule is consulted.",
                 "model_info": {
                     "litellm_provider": "bedrock"
                 }

model_prices_and_context_window.json

@@ -45284,8 +45284,8 @@
         "rules": [
             {
                 "name": "bedrock-claude-ids",
-                "pattern": "anthropic\\.claude-",
-                "description": "Any Bedrock-syntax Claude id: the dotted anthropic.claude- segment appears in bare (anthropic.claude-...), region-prefixed (us./eu./au./jp./apac.) and global.-prefixed ids, for every version. Routes these to bedrock before the bare-id Anthropic rule is consulted.",
+                "pattern": "^(?:[a-z-]+\\.)?anthropic\\.claude-",
+                "description": "A Bedrock-syntax Claude id, for every version: anthropic.claude- at the start of the name, optionally behind a single dotted geo segment (us./eu./au./jp./apac./global./us-gov.). Anchored to the start because routing rules see the raw request string and provider inference feeds the proxy's provider/* wildcard access checks: an id under an unrecognized namespace such as bedrockz/anthropic.claude-... must stay unroutable rather than resolve to bedrock and slip through a bedrock/* key. Routes to bedrock before the bare-id Anthropic rule is consulted.",
                 "model_info": {
                     "litellm_provider": "bedrock"
                 }

tests/test_litellm/litellm_core_utils/test_get_model_cost_map.py

@@ -138,6 +138,42 @@ def test_shipped_backup_carries_the_claude_routing_rules():
         set_fallback_generalizations(previous)
 
 
+def test_shipped_routing_rules_never_match_through_an_unrecognized_namespace():
+    """Routing rules decide ``litellm_provider`` for otherwise-unknown ids, and the
+    proxy's wildcard access check (``can_key_call_model`` with a ``bedrock/*`` key)
+    trusts that inference: it rebuilds ``{provider}/{model}`` and matches it against
+    the key's patterns. A routing pattern that matches as a substring lets
+    ``bedrockz/anthropic.claude-...`` resolve to bedrock and slip through a
+    ``bedrock/*`` key, so every shipped routing rule must anchor to the start of
+    the name and never match an id carrying an unrecognized namespace prefix."""
+    backup = GetModelCostMap.load_local_model_cost_map()
+    rules = backup[FALLBACK_GENERALIZATIONS_KEY]["rules"]
+
+    routing_rules = [r for r in rules if "litellm_provider" in r["model_info"]]
+    assert routing_rules
+    assert all(r["pattern"].startswith("^") for r in routing_rules)
+
+    previous = list(get_fallback_generalization_rules())
+    try:
+        set_fallback_generalizations(rules)
+        for bedrock_id in [
+            "anthropic.claude-3-5-sonnet-20240620-v1:0",
+            "anthropic.claude-v2:1",
+            "us.anthropic.claude-sonnet-4-5-20250929-v1:0",
+            "us-gov.anthropic.claude-3-5-sonnet-20240620-v1:0",
+            "global.anthropic.claude-fable-5-20260120-v1:0",
+        ]:
+            assert match_routing_generalization(bedrock_id) == "bedrock", bedrock_id
+        for namespaced in [
+            "bedrockz/anthropic.claude-3-5-sonnet-20240620",
+            "bedrockz/us.anthropic.claude-3-5-sonnet-20240620-v1:0",
+            "bedrockz/claude-3-5-sonnet-20240620",
+        ]:
+            assert match_routing_generalization(namespaced) is None, namespaced
+    finally:
+        set_fallback_generalizations(previous)
+
+
 def test_shipped_backup_marks_claude_4_6_plus_adaptive_not_4_0():
     """Adaptive thinking is data, not code. The bundled backup must carry
     supports_adaptive_thinking on genuine Claude >= 4.6 entries (every provider