diff --git a/python/tests/e2e/conftest.py b/python/tests/e2e/conftest.py
index d3d311f..bf28a8a 100644
--- a/python/tests/e2e/conftest.py
+++ b/python/tests/e2e/conftest.py
@@ -30,7 +30,33 @@
 import pytest
 
 from xagent_sdk import AgentClient, UserClient
-from xagent_sdk.cloud import WorkspaceClient
+from xagent_sdk.cloud import Region, WorkspaceClient
+
+
+def _cloud_base_url() -> str | None:
+    """Resolve the cloud host for e2e: explicit ``XAGENT_BASE_URL`` wins,
+    else the host for ``XAGENT_REGION`` (``au``/``sg``). Returns ``None``
+    when neither is set -- there is no hosted default to guess, since the
+    service is per-region.
+    """
+    explicit = os.environ.get("XAGENT_BASE_URL")
+    if explicit:
+        return explicit
+    region = os.environ.get("XAGENT_REGION")
+    if region:
+        return Region(region.strip().lower()).base_url
+    return None
+
+
+def _need_workspace() -> tuple[str, str]:
+    workspace_key = os.environ.get("XAGENT_WORKSPACE_KEY")
+    base_url = _cloud_base_url()
+    if not (workspace_key and base_url):
+        pytest.skip(
+            "e2e cloud surface requires XAGENT_WORKSPACE_KEY and "
+            "XAGENT_BASE_URL or XAGENT_REGION"
+        )
+    return workspace_key, base_url
 
 
 def _need_personal() -> tuple[str, str]:
@@ -91,20 +117,30 @@ def patient_agent_client() -> Iterator[AgentClient]:
         yield c
 
 
+@pytest.fixture
+def cloud_base_url() -> str:
+    """Resolved cloud host for tests that build their own client (e.g. a
+    bad-key probe). Skips when no ``XAGENT_BASE_URL`` / ``XAGENT_REGION``
+    is set, since the service is per-region and has no default host.
+    """
+    base_url = _cloud_base_url()
+    if base_url is None:
+        pytest.skip("e2e cloud surface requires XAGENT_BASE_URL or XAGENT_REGION")
+    return base_url
+
+
 @pytest.fixture
 def workspace_client() -> Iterator[WorkspaceClient]:
     """WorkspaceClient authenticated with a workspace key.
 
-    Requires ``XAGENT_WORKSPACE_KEY``; ``base_url`` falls back to
-    ``XAGENT_BASE_URL`` and then the hosted default, so a developer
-    pointing at a staging deploy sets ``XAGENT_BASE_URL`` while one
-    hitting the hosted service sets only the key. 60s per-request timeout
-    so agent runs created here have room to complete.
+    Requires ``XAGENT_WORKSPACE_KEY`` plus an explicit host -- either
+    ``XAGENT_BASE_URL`` (staging / self-host) or ``XAGENT_REGION``
+    (``au``/``sg``). The service is per-region, so a key only authenticates
+    against the region that minted it; there is no default host to fall
+    back to. 60s per-request timeout so agent runs created here have room
+    to complete.
     """
-    workspace_key = os.environ.get("XAGENT_WORKSPACE_KEY")
-    if not workspace_key:
-        pytest.skip("e2e workspace surface requires XAGENT_WORKSPACE_KEY")
-    base_url = os.environ.get("XAGENT_BASE_URL")
+    workspace_key, base_url = _need_workspace()
     with WorkspaceClient(
         workspace_key=workspace_key, base_url=base_url, timeout=60.0
     ) as c:
diff --git a/python/tests/e2e/test_cloud_smoke.py b/python/tests/e2e/test_cloud_smoke.py
index 5fc144f..93c4280 100644
--- a/python/tests/e2e/test_cloud_smoke.py
+++ b/python/tests/e2e/test_cloud_smoke.py
@@ -3,8 +3,9 @@
 Marked ``@pytest.mark.e2e`` so the default ``pytest`` run skips them.
 Run against a SaaS deploy with a workspace key::
 
-    XAGENT_WORKSPACE_KEY=xag_workspace_... uv run pytest -m e2e
-    # XAGENT_BASE_URL optional; defaults to the hosted endpoint
+    XAGENT_WORKSPACE_KEY=xag_workspace_... XAGENT_REGION=sg uv run pytest -m e2e
+    # Set XAGENT_REGION (au/sg) or XAGENT_BASE_URL (staging/self-host);
+    # the service is per-region and has no default host.
 
 ``E2E_TEMPLATE_ID`` picks the template to instantiate (defaults to the
 first listed). The created agent is not deleted -- run on a scratch
@@ -27,13 +28,9 @@
 pytestmark = pytest.mark.e2e
 
 
-def _runtime_base_url() -> str:
-    # The minted runtime key drives the existing /v1/chat/tasks* surface
-    # on the same host the workspace client targets.
-    return os.environ.get("XAGENT_BASE_URL") or "https://cloud.xagent.run"
-
-
-def test_workspace_full_flow(workspace_client: WorkspaceClient) -> None:
+def test_workspace_full_flow(
+    workspace_client: WorkspaceClient, cloud_base_url: str
+) -> None:
     templates = workspace_client.templates.list()
     if not templates:
         pytest.skip("workspace exposes no templates; nothing to instantiate")
@@ -46,8 +43,10 @@ def test_workspace_full_flow(workspace_client: WorkspaceClient) -> None:
     assert created.runtime_full_key is not None
     assert created.runtime_full_key.startswith("xag_")
 
+    # The minted runtime key drives the /v1/chat/tasks* surface on the
+    # same host the workspace client targets.
     with AgentClient(
-        api_key=created.runtime_full_key, base_url=_runtime_base_url(), timeout=120.0
+        api_key=created.runtime_full_key, base_url=cloud_base_url, timeout=120.0
     ) as runtime:
         result = runtime.tasks.run(
             agent_id=created.agent_id,
@@ -65,12 +64,11 @@ def test_unknown_template_raises(workspace_client: WorkspaceClient) -> None:
         workspace_client.agents.create_from_template("does-not-exist-12345")
 
 
-def test_bad_workspace_key_unauthorized() -> None:
-    base_url = os.environ.get("XAGENT_BASE_URL")
-    if not os.environ.get("XAGENT_WORKSPACE_KEY"):
-        pytest.skip("e2e workspace surface requires XAGENT_WORKSPACE_KEY")
+def test_bad_workspace_key_unauthorized(cloud_base_url: str) -> None:
     with (
-        WorkspaceClient(workspace_key="xag_workspace_bad_key", base_url=base_url) as c,
+        WorkspaceClient(
+            workspace_key="xag_workspace_bad_key", base_url=cloud_base_url
+        ) as c,
         pytest.raises(InvalidAPIKey),
     ):
         c.agents.list()