diff --git a/agentlightning/server/app.py b/agentlightning/server/app.py
index 9f94a59e8..1b90eae51 100644
--- a/agentlightning/server/app.py
+++ b/agentlightning/server/app.py
@@ -39,7 +39,9 @@ async def verify_key(request: Request) -> None:
             return
 
         auth_header = request.headers.get("authorization", "")
-        if auth_header.startswith("Bearer ") and auth_header[7:] == key:
+        # RFC 7235 §2.1: auth-scheme is case-insensitive; allow one or more spaces.
+        parts = auth_header.split(None, 1)
+        if len(parts) == 2 and parts[0].casefold() == "bearer" and parts[1] == key:
             return
 
         if request.headers.get("x-api-key", "") == key:
diff --git a/tests/server/test_endpoints.py b/tests/server/test_endpoints.py
index e23fadfae..559947f4f 100644
--- a/tests/server/test_endpoints.py
+++ b/tests/server/test_endpoints.py
@@ -8,7 +8,7 @@
 import pytest
 from fastapi.testclient import TestClient
 
-from tests.server.conftest import MODEL_NAME
+from tests.server.conftest import AGL_KEY, MODEL_NAME
 
 
 def _rollout(client: TestClient, headers: dict[str, str]) -> dict:
@@ -40,6 +40,62 @@ def test_auth_required(client: TestClient):
     assert client.post("/api/rollouts", json=[]).status_code == 401
 
 
+@pytest.mark.parametrize(
+    "authorization",
+    [
+        f"Bearer {AGL_KEY}",
+        f"bearer {AGL_KEY}",
+        f"BEARER {AGL_KEY}",
+        f"BeArEr {AGL_KEY}",
+        f"Bearer  {AGL_KEY}",
+    ],
+)
+def test_bearer_auth_accepts_case_insensitive_scheme(client: TestClient, authorization: str):
+    # Hit the real auth dependency through a store route (issue #671).
+    response = client.get("/api/rollouts", params={"state_in": "queuing"}, headers={"Authorization": authorization})
+    assert response.status_code == 200
+    assert response.json() == []
+
+
+def test_x_api_key_auth_still_accepted(client: TestClient):
+    response = client.get(
+        "/api/rollouts",
+        params={"state_in": "queuing"},
+        headers={"x-api-key": AGL_KEY},
+    )
+    assert response.status_code == 200
+    assert response.json() == []
+
+
+@pytest.mark.parametrize(
+    "headers",
+    [
+        {},
+        {"Authorization": f"Bearer wrong-{AGL_KEY}"},
+        {"Authorization": f"bearer wrong-{AGL_KEY}"},
+        {"Authorization": f"Basic {AGL_KEY}"},
+        {"Authorization": f"Token {AGL_KEY}"},
+        {"Authorization": "Bearer"},
+        {"Authorization": AGL_KEY},
+        {"x-api-key": f"wrong-{AGL_KEY}"},
+    ],
+    ids=[
+        "missing",
+        "wrong-key-canonical",
+        "wrong-key-lower",
+        "basic-scheme",
+        "token-scheme",
+        "scheme-only",
+        "bare-key",
+        "wrong-x-api-key",
+    ],
+)
+def test_auth_rejects_invalid_credentials(client: TestClient, headers: dict[str, str]):
+    response = client.get("/api/rollouts", params={"state_in": "queuing"}, headers=headers)
+    assert response.status_code == 401
+    assert response.json() == {"detail": "Invalid or missing API key"}
+
+
 def test_rollout_endpoints(client: TestClient, auth_headers: dict[str, str]):
     rollout = _rollout(client, auth_headers)
     assert rollout["input"] == {"prompt": "hi"}