Implement optional authentication (Anthropic style) (#80)

tests/api/test_auth.py

@@ -0,0 +1,57 @@
+from unittest.mock import patch
+
+from fastapi.testclient import TestClient
+
+from api.app import app
+from api.dependencies import get_settings
+from config.settings import Settings
+
+
+def test_anthropic_auth_token_required_and_accepts_x_api_key():
+    client = TestClient(app)
+    settings = Settings()
+    settings.anthropic_auth_token = "s3cr3t"
+    app.dependency_overrides[get_settings] = lambda: settings
+
+    payload = {
+        "model": "claude-3-sonnet",
+        "messages": [{"role": "user", "content": "hello"}],
+    }
+
+    with patch("api.routes.get_token_count", return_value=1):
+        # No header -> 401
+        r = client.post("/v1/messages/count_tokens", json=payload)
+        assert r.status_code == 401
+
+        # X-API-Key header -> 200
+        r = client.post(
+            "/v1/messages/count_tokens", json=payload, headers={"X-API-Key": "s3cr3t"}
+        )
+        assert r.status_code == 200
+        assert r.json()["input_tokens"] == 1
+
+    app.dependency_overrides.clear()
+
+
+def test_anthropic_auth_token_accepts_bearer_authorization():
+    client = TestClient(app)
+    settings = Settings()
+    settings.anthropic_auth_token = "b3artoken"
+    app.dependency_overrides[get_settings] = lambda: settings
+
+    payload = {
+        "model": "claude-3-sonnet",
+        "messages": [{"role": "user", "content": "hello"}],
+    }
+
+    with patch("api.routes.get_token_count", return_value=2):
+        # Authorization Bearer -> 200
+        r = client.post(
+            "/v1/messages/count_tokens",
+            json=payload,
+            headers={"Authorization": "Bearer b3artoken"},
+        )
+        assert r.status_code == 200
+        assert r.json()["input_tokens"] == 2
+
+    app.dependency_overrides.clear()

tests/conftest.py

@@ -9,6 +9,9 @@ import pytest
 os.environ.setdefault("NVIDIA_NIM_API_KEY", "test_key")
 os.environ.setdefault("MODEL", "nvidia_nim/test-model")
 os.environ["PTB_TIMEDELTA"] = "1"
+# Ensure tests don't pick up a server API key from the repo .env
+# (tests expect endpoints to be unauthenticated by default)
+os.environ["ANTHROPIC_AUTH_TOKEN"] = ""
 
 from typing import Any
 from unittest.mock import AsyncMock, MagicMock