Structure missing-token authentication errors

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 0.1.2 - 2026-07-26
+
+- Raised a structured `DataNetError` when an authentication response succeeds
+  without returning a usable JWT.
+
 ## 0.1.1 - 2026-07-17
 
 - Added `get_presence(channel)` for authoritative occupancy and member lookups.

datanet/__init__.py

@@ -32,4 +32,4 @@
     "build_art_dmx_packet",
     "build_dmx_frame",
 ]
-__version__ = "0.1.1"
+__version__ = "0.1.2"

datanet/client.py

@@ -953,11 +953,15 @@ async def _fetch_jwt(self) -> str:
                         code=code,
                         status=resp.status,
                     )
-                payload = await resp.json()
-                token = payload.get("token")
-                if not token:
-                    raise RuntimeError(
-                        f"DataNet auth failed: missing token in response {payload!r}"
+                body = await resp.json()
+                token = body.get("token") if isinstance(body, dict) else None
+                if not isinstance(token, str) or not token.strip():
+                    detail = body.get("error") if isinstance(body, dict) else None
+                    raise DataNetError(
+                        f"DataNet auth failed ({resp.status}): "
+                        f"{detail or 'response missing token'}",
+                        code="authentication_failed",
+                        status=resp.status,
                     )
                 logger.debug("DataNet: JWT acquired.")
                 return token

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "datanet-sdk"
-version = "0.1.1"
+version = "0.1.2"
 description = "DataNet Python SDK — async realtime pub/sub client for the DataNet platform"
 readme = "README.md"
 license = { text = "MIT" }

tests/test_client.py

@@ -8,6 +8,7 @@
     AnyMessage,
     BinaryMessageMeta,
     DataNet,
+    DataNetError,
     MessageMeta,
     binary_to_base64,
     build_art_dmx_packet,
@@ -63,6 +64,17 @@ def post(self, url, **kwargs):
         return FakePostResponse()
 
 
+class FakeMissingTokenResponse(FakePostResponse):
+    async def json(self):
+        return {"error": "invalid apiKey"}
+
+
+class FakeMissingTokenSession(FakeClientSession):
+    def post(self, url, **kwargs):
+        self.calls.append((url, kwargs))
+        return FakeMissingTokenResponse()
+
+
 class FakePresenceResponse:
     status = 200
 
@@ -393,6 +405,21 @@ async def test_auth_payload_includes_device_metadata(self):
             },
         )
 
+    async def test_auth_response_without_token_raises_structured_error(self):
+        client = DataNet("ak_invalid")
+
+        with patch.object(
+            client_module.aiohttp,
+            "ClientSession",
+            FakeMissingTokenSession,
+        ):
+            with self.assertRaises(DataNetError) as raised:
+                await client._fetch_jwt()
+
+        self.assertEqual(raised.exception.code, "authentication_failed")
+        self.assertEqual(raised.exception.status, 200)
+        self.assertIn("invalid apiKey", str(raised.exception))
+
     async def test_heartbeat_sends_hb_envelope(self):
         client = DataNet("ak_test")
         ws = FakeWebSocket()