diff --git a/arbsphere/__init__.py b/arbsphere/__init__.py
index 09f19be..b06bb7a 100644
--- a/arbsphere/__init__.py
+++ b/arbsphere/__init__.py
@@ -6,15 +6,20 @@ federated arbitrage engine; here we only provide deterministic, testable
 behaviors.
 """
 
-from .primitives import LocalArbProblem, SharedSignals  # noqa: F401
+from .primitives import LocalArbProblem, SharedSignals, DualVariables, AuditLog, PrivacyBudget  # noqa: F401
 from .coordinator import admm_lite_step  # noqa: F401
 from .ir import map_to_ir  # noqa: F401
 from .go_registry import GoCRegistry  # noqa: F401
+from .two_venue_demo import run_demo  # noqa: F401
 
 __all__ = [
     "LocalArbProblem",
     "SharedSignals",
+    "DualVariables",
+    "AuditLog",
+    "PrivacyBudget",
     "admm_lite_step",
     "map_to_ir",
     "GoCRegistry",
+    "run_demo",
 ]
diff --git a/arbsphere/primitives.py b/arbsphere/primitives.py
index d8fac92..00ca84f 100644
--- a/arbsphere/primitives.py
+++ b/arbsphere/primitives.py
@@ -1,5 +1,5 @@
 from dataclasses import dataclass
-from typing import List, Tuple, Dict
+from typing import List, Tuple, Dict, Any
 
 
 @dataclass(frozen=True)
@@ -16,3 +16,32 @@ class SharedSignals:
     cross_venue_corr: float
     liquidity_availability: Dict[str, float]
     latency_proxy: float
+
+
+@dataclass
+class DualVariables:
+    """Federated optimization dual variables (shadow prices per asset pair).
+
+    This is a lightweight stand-in for the real project's duals used by the
+    ADMM-like coordinator to balance cross-venue objectives.
+    """
+    shadow_prices: Dict[str, float]
+
+
+@dataclass
+class AuditLogEntry:
+    ts: float
+    event: str
+    details: Dict[str, Any]
+    signature: str
+
+
+@dataclass
+class AuditLog:
+    entries: List[AuditLogEntry]
+
+
+@dataclass
+class PrivacyBudget:
+    """Simple privacy budget per signal source or metric."""
+    budgets: Dict[str, float]
diff --git a/arbsphere/two_venue_demo.py b/arbsphere/two_venue_demo.py
new file mode 100644
index 0000000..237f04c
--- /dev/null
+++ b/arbsphere/two_venue_demo.py
@@ -0,0 +1,57 @@
+from __future__ import annotations
+
+"""Toy two-venue ArbSphere demo.
+
+This module wires two toy adapters (price feed and broker) from two venues
+and demonstrates a minimal federated compute step using the existing ADMM-lite
+coordinator API.
+"""
+
+import time
+from typing import List
+from arbsphere.primitives import LocalArbProblem, SharedSignals
+from arbsphere.coordinator import admm_lite_step
+from arbsphere.adapters.price_feed_adapter import PriceFeedAdapter
+from arbsphere.adapters.broker_adapter import BrokerAdapter
+
+
+def run_demo() -> None:
+    # Define two toy venues with simple, deterministic budgets
+    lp1 = LocalArbProblem(asset_pair=("AAPL", "MSFT"), target_mispricing=0.5, liquidity_budget=1000.0, latency_budget=5.0)
+    lp2 = LocalArbProblem(asset_pair=("GOOG", "AMZN"), target_mispricing=0.7, liquidity_budget=800.0, latency_budget=6.0)
+
+    shared = SharedSignals(
+        deltas=[0.1, -0.05],
+        cross_venue_corr=0.25,
+        liquidity_availability={"venue-1": 0.8, "venue-2": 0.75},
+        latency_proxy=0.9,
+    )
+
+    # Step 1: compute a delta (toy) via admm_lite_step
+    delta = admm_lite_step([lp1, lp2], shared)
+
+    print("Generated PlanDelta:")
+    print(delta)
+
+    # Step 2: route using toy broker adapters (two venues)
+    broker_a = BrokerAdapter(venue_name="venue-1")
+    broker_b = BrokerAdapter(venue_name="venue-2")
+
+    # Create simple per-venue plan deltas; in a real system this would be split by venue
+    plan_for_venue_a = {"legs": delta.legs, "total_size": delta.total_size}
+    plan_for_venue_b = {"legs": delta.legs, "total_size": delta.total_size}
+
+    broker_a.route(plan_for_venue_a)
+    broker_b.route(plan_for_venue_b)
+
+    print("Venue-1 execution history:", broker_a.history())
+    print("Venue-2 execution history:", broker_b.history())
+
+
+def main() -> None:
+    print("Starting ArbSphere two-venue demo...")
+    run_demo()
+
+
+if __name__ == "__main__":
+    main()