diff --git a/routstr/upstream/routstr.py b/routstr/upstream/routstr.py
index abf82a33..ab6dd0bd 100644
--- a/routstr/upstream/routstr.py
+++ b/routstr/upstream/routstr.py
@@ -83,7 +83,7 @@ class RoutstrUpstreamProvider(BaseUpstreamProvider):
             Balance in satoshis, or None if failed
         """
         url = f"{self.base_url}/v1/balance/info"
-        headers = {"Authorization": f"Bearer {self.api_key}"}
+        headers = {"Authorization": f"Bearer {self.api_key}"} if self.api_key else {}
 
         async with httpx.AsyncClient() as client:
             try:
diff --git a/tests/unit/test_upstream_routstr.py b/tests/unit/test_upstream_routstr.py
new file mode 100644
index 00000000..8cb2427d
--- /dev/null
+++ b/tests/unit/test_upstream_routstr.py
@@ -0,0 +1,76 @@
+from types import TracebackType
+from unittest.mock import Mock
+
+import httpx
+import pytest
+
+from routstr.upstream.routstr import RoutstrUpstreamProvider
+
+
+class DummyAsyncClient:
+    def __init__(self, response: Mock | None = None, error: Exception | None = None):
+        self.response = response
+        self.error = error
+        self.calls: list[dict[str, object]] = []
+
+    async def __aenter__(self) -> "DummyAsyncClient":
+        return self
+
+    async def __aexit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc: BaseException | None,
+        tb: TracebackType | None,
+    ) -> bool:
+        return False
+
+    async def get(
+        self, url: str, headers: dict[str, str], timeout: float
+    ) -> Mock:
+        self.calls.append({"url": url, "headers": headers, "timeout": timeout})
+        if self.error is not None:
+            raise self.error
+        assert self.response is not None
+        return self.response
+
+
+@pytest.mark.asyncio
+async def test_get_balance_omits_auth_header_when_api_key_missing(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    response = Mock()
+    response.json.return_value = {"balance_msats": 42000}
+    response.raise_for_status.return_value = None
+
+    client = DummyAsyncClient(response=response)
+    monkeypatch.setattr("routstr.upstream.routstr.httpx.AsyncClient", lambda: client)
+
+    provider = RoutstrUpstreamProvider(base_url="https://node.example", api_key="")
+
+    balance = await provider.get_balance()
+
+    assert balance == 42.0
+    assert client.calls == [
+        {
+            "url": "https://node.example/v1/balance/info",
+            "headers": {},
+            "timeout": 10.0,
+        }
+    ]
+
+
+@pytest.mark.asyncio
+async def test_get_balance_returns_none_on_connect_timeout(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    client = DummyAsyncClient(error=httpx.ConnectTimeout("timed out"))
+    monkeypatch.setattr("routstr.upstream.routstr.httpx.AsyncClient", lambda: client)
+
+    provider = RoutstrUpstreamProvider(
+        base_url="https://node.example",
+        api_key="secret",
+    )
+
+    balance = await provider.get_balance()
+
+    assert balance is None