nanobot/providers/registry.py

@@ -460,3 +460,24 @@ def find_by_name(name: str) -> ProviderSpec | None:
         if spec.name == name:
             return spec
     return None
+
+
+def should_use_oauth_provider(api_key: str | None, model: str) -> bool:
+    """Determine if OAuth provider should be used.
+
+    OAuth provider is used when:
+    1. API key is an OAuth token (contains 'sk-ant-oat')
+    2. Model is an Anthropic model (contains 'claude' or 'anthropic')
+    """
+    if not api_key:
+        return False
+
+    if "sk-ant-oat" not in api_key:
+        return False
+
+    model_lower = model.lower()
+    anthropic_spec = find_by_name("anthropic")
+    if anthropic_spec:
+        return any(kw in model_lower for kw in anthropic_spec.keywords)
+
+    return False

tests/test_registry_oauth.py

@@ -0,0 +1,21 @@
+"""Test OAuth detection in provider registry."""
+import pytest
+from nanobot.providers.registry import should_use_oauth_provider
+
+
+def test_should_use_oauth_for_oat_token():
+    """OAuth provider should be used for sk-ant-oat tokens."""
+    assert should_use_oauth_provider("sk-ant-oat01-xxx", "anthropic/claude-opus-4-5") is True
+    assert should_use_oauth_provider("sk-ant-oat01-xxx", "claude-sonnet-4") is True
+
+
+def test_should_not_use_oauth_for_regular_key():
+    """Regular API keys should not use OAuth provider."""
+    assert should_use_oauth_provider("sk-ant-api03-xxx", "claude-opus-4-5") is False
+    assert should_use_oauth_provider("sk-or-v1-xxx", "anthropic/claude-opus-4-5") is False
+
+
+def test_should_not_use_oauth_for_non_anthropic():
+    """Non-Anthropic models should not use OAuth provider."""
+    assert should_use_oauth_provider("sk-ant-oat01-xxx", "gpt-4") is False
+    assert should_use_oauth_provider("sk-ant-oat01-xxx", "deepseek/deepseek-chat") is False