diff --git a/python/tests/test_cli_flags.py b/python/tests/test_cli_flags.py
index bae006f..6a01587 100644
--- a/python/tests/test_cli_flags.py
+++ b/python/tests/test_cli_flags.py
@@ -2,9 +2,11 @@
 
 from __future__ import annotations
 
+from unittest.mock import Mock
+
 import pytest
 
-from edge0.cli import _build_parser, _engine_kwargs
+from edge0.cli import TIER_ENV, _build_parser, _engine_kwargs
 
 
 @pytest.mark.parametrize("cmd", ["demo", "chat", "serve"])
@@ -31,3 +33,31 @@ def test_serve_keeps_its_own_flags():
     args = _build_parser().parse_args(
         ["serve", "edge0-8b", "--host", "0.0.0.0", "--port", "9"])
     assert (args.host, args.port) == ("0.0.0.0", 9)
+
+
+@pytest.mark.parametrize("cmd", ["demo", "chat", "serve"])
+@pytest.mark.parametrize("tier", ["edge0-8b", "edge0-35b"])
+@pytest.mark.parametrize("no_prerouter", [False, True])
+def test_entrypoint_preserves_prerouter_contract(
+        cmd, tier, no_prerouter, monkeypatch, tmp_path):
+    """Check actual CLI dispatch without constructing an inference engine."""
+    from edge0 import AutoEngine
+
+    class EngineConstructionReached(Exception):
+        pass
+
+    factory = Mock(side_effect=EngineConstructionReached)
+    monkeypatch.setattr(AutoEngine, "from_pretrained", factory)
+    monkeypatch.setenv(TIER_ENV[tier], str(tmp_path))
+    argv = [cmd, tier]
+    if no_prerouter:
+        argv.append("--no-prerouter")
+    args = _build_parser().parse_args(argv)
+
+    with pytest.raises(EngineConstructionReached):
+        args.fn(args)
+
+    expected = {}
+    if no_prerouter or (cmd == "demo" and tier == "edge0-8b"):
+        expected["prerouter"] = None
+    factory.assert_called_once_with(str(tmp_path), name=tier, **expected)