diff --git a/README.md b/README.md
index 2a4d8b0..5b2f04d 100644
--- a/README.md
+++ b/README.md
@@ -30,3 +30,11 @@ Next steps (high level)
 - Add delta-sync protocol scaffolding and an auditable reconciliation log
 
 This work aligns with the roadmap described in AGENTS.md and is designed to be extended incrementally.
+CatOpt Bridge (MVP)
+- The CosmosMesh MVP includes a minimal CatOpt-style bridge that maps local optimization primitives
+  to a canonical representation suitable for cross-domain adapters. This scaffold provides:
+- LocalProblem, SharedVariable, and DualVariable primitives and a lightweight round-trip message format.
+- A small in-memory contract registry to version primitives and schemas.
+- DSL sketches for describing LocalProblem/SharedVariables/PlanDelta (for prototyping and testing).
+
+- Usage example: see examples/catopt_demo.py for a quick end-to-end round-trip construction.
diff --git a/examples/catopt_demo.py b/examples/catopt_demo.py
new file mode 100644
index 0000000..1ea0d64
--- /dev/null
+++ b/examples/catopt_demo.py
@@ -0,0 +1,35 @@
+"""CatOpt Bridge Demo (CosmosMesh MVP)
+
+Minimal end-to-end example showing how to construct a LocalProblem, SharedVariables,
+DualVariables and build a RoundTrip message via the CatOptBridge.
+"""
+from cosmosmesh_privacy_preserving_federated.catopt_bridge import LocalProblem, SharedVariable, DualVariable, CatOptBridge
+
+
+def main():
+    # Define a tiny local problem for a two-asset scenario
+    lp = LocalProblem(
+        problem_id="rover1-task-allocation",
+        objective="minimize energy consumption",
+        variables=["x1", "x2"],
+        constraints=["x1 + x2 <= 10", "x1 >= 0", "x2 >= 0"],
+        version=1,
+    )
+
+    # Shared variables (primal signals) between agents
+    sv1 = SharedVariable(name="eta1", value=0.5, version=1)
+    sv2 = SharedVariable(name="eta2", value=1.2, version=1)
+    dual1 = DualVariable(name="lambda1", value=0.1, version=1)
+
+    # Build a round-trip message as the CatOptBridge would prepare for transport
+    rt = CatOptBridge.build_round_trip(
+        problem=lp,
+        shared=[sv1, sv2],
+        duals=[dual1],
+    )
+
+    print("RoundTrip Message:\n", rt)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tests/test_catopt_demo.py b/tests/test_catopt_demo.py
new file mode 100644
index 0000000..7e158fb
--- /dev/null
+++ b/tests/test_catopt_demo.py
@@ -0,0 +1,27 @@
+import json
+
+from cosmosmesh_privacy_preserving_federated.catopt_bridge import LocalProblem, SharedVariable, DualVariable, CatOptBridge
+
+
+def test_round_trip_construction():
+    lp = LocalProblem(
+        problem_id="test-problem",
+        objective="maximize throughput",
+        variables=["x"],
+        constraints=["x >= 0"],
+        version=1,
+    )
+    sv = [SharedVariable(name="s", value=3.14, version=1)]
+    dv = [DualVariable(name="d", value=2.718, version=1)]
+
+    msg = CatOptBridge.build_round_trip(problem=lp, shared=sv, duals=dv)
+    # Basic sanity checks on the envelope
+    assert isinstance(msg, dict)
+    assert msg.get("kind") == "RoundTrip"
+    payload = msg.get("payload")
+    assert isinstance(payload, dict)
+    assert payload.get("object")["id"] == lp.problem_id
+    # ensure morphisms present
+    morphisms = payload.get("morphisms")
+    assert isinstance(morphisms, list)
+    assert any(isinstance(m, dict) and m.get("name") == "s" for m in morphisms)