diff --git a/mercurymesh_federated_reproducible_marke/adapters.py b/mercurymesh_federated_reproducible_marke/adapters.py
index 73b7134..6ba333b 100644
--- a/mercurymesh_federated_reproducible_marke/adapters.py
+++ b/mercurymesh_federated_reproducible_marke/adapters.py
@@ -63,3 +63,6 @@ def phase0_demo(adapter_a: ExchangeDataFeedAdapter, adapter_b: ExchangeDataFeedA
 
     delta = FederatedCoordinator.aggregate_signals(signals)
     return delta
+
+# Public API surface for MVP wiring exploration
+__all__ = ["ExchangeDataFeedAdapter", "VenueBrokerAdapter", "phase0_demo"]
diff --git a/mercurymesh_federated_reproducible_marke/tests/test_adapters_phase0.py b/mercurymesh_federated_reproducible_marke/tests/test_adapters_phase0.py
new file mode 100644
index 0000000..5305ce0
--- /dev/null
+++ b/mercurymesh_federated_reproducible_marke/tests/test_adapters_phase0.py
@@ -0,0 +1,20 @@
+import pytest
+
+from mercurymesh_federated_reproducible_marke.adapters import ExchangeDataFeedAdapter, phase0_demo
+from mercurymesh_federated_reproducible_marke.core import PlanDelta
+
+
+def test_phase0_demo_end_to_end_basic_signals_aggregation():
+    a = ExchangeDataFeedAdapter("exchangeA")
+    b = ExchangeDataFeedAdapter("exchangeB")
+
+    # Monkeypatch fetch_signals to return deterministic signals for test
+    a.fetch_signals = lambda: [{"A": 1.0}]
+    b.fetch_signals = lambda: [{"A": -0.5}, {"B": 2.0}]
+
+    delta = phase0_demo(a, b)
+
+    assert isinstance(delta, PlanDelta)
+    # Expect averaged delta across three signals: A: (1.0-0.5)/3, B: 2.0/3
+    assert pytest.approx(delta.delta.get("A", 0.0), rel=1e-9) == pytest.approx(0.5/3, rel=1e-9)
+    assert pytest.approx(delta.delta.get("B", 0.0), rel=1e-9) == pytest.approx(2.0/3, rel=1e-9)