diff --git a/spacesafeml_certification_benchmark_and_/examples/demo.py b/spacesafeml_certification_benchmark_and_/examples/demo.py
new file mode 100644
index 0000000..00db427
--- /dev/null
+++ b/spacesafeml_certification_benchmark_and_/examples/demo.py
@@ -0,0 +1,55 @@
+"""Small demo runner that certifies a plan and records the attestation to the ledger.
+
+This demonstrates how the DSL, verifier, and ledger tie together and can be
+used as a starting point for real adapters and HIL integrations.
+"""
+from __future__ import annotations
+
+import json
+from typing import Dict, Any
+
+from ..dsl import SafetyContract, LocalCapabilities, ResourceBudgets, DataSharingPolicy
+from ..verification import VerificationEngine
+from ..governance.ledger import Ledger
+
+
+def run_demo(contract: SafetyContract, plan: Dict[str, Any]) -> Dict[str, Any]:
+    """Run a deterministic demo: certify plan and add certificate to ledger.
+
+    Returns a dict with certificate and the ledger entry dict.
+    """
+    engine = VerificationEngine()
+    ledger = Ledger()
+
+    cert = engine.certify(plan, contract)
+
+    # Record attestation in the ledger with minimal metadata
+    payload = {
+        "contract_id": getattr(contract, "contract_id", None),
+        "plan_hash": cert.get("plan_hash"),
+        "certificate_id": cert.get("certificate_id"),
+        "status": cert.get("status"),
+    }
+    entry = ledger.add_entry(payload)
+
+    return {"certificate": cert, "ledger_entry": entry.__dict__, "chain": ledger.get_chain()}
+
+
+def demo_cli() -> None:
+    """Create a sample contract/plan, run the demo and print JSON output."""
+    contract = SafetyContract(
+        contract_id="demo-contract-1",
+        local_capabilities=[LocalCapabilities(name="Planner", capabilities=["plan"])],
+        budgets=ResourceBudgets(cpu_cores=1.0, memory_gb=1.0, energy_wh=50.0, time_seconds=600),
+        data_policy=DataSharingPolicy(policy_id="demo-policy", allowed_data=["telemetry"]),
+        version="1.0",
+    )
+
+    plan = {"name": "demo-mission", "actions": ["scan", "navigate"], "budgets": {"cpu_cores": 0.5}}
+
+    out = run_demo(contract, plan)
+    print(json.dumps(out, indent=2))
+
+
+if __name__ == "__main__":
+    demo_cli()
diff --git a/tests/test_demo.py b/tests/test_demo.py
new file mode 100644
index 0000000..c920d39
--- /dev/null
+++ b/tests/test_demo.py
@@ -0,0 +1,27 @@
+from spacesafeml_certification_benchmark_and_.examples.demo import run_demo
+from spacesafeml_certification_benchmark_and_.dsl import (
+    SafetyContract,
+    LocalCapabilities,
+    ResourceBudgets,
+    DataSharingPolicy,
+)
+
+
+def test_demo_records_certificate_and_ledger_entry():
+    contract = SafetyContract(
+        contract_id="demo-test-1",
+        local_capabilities=[LocalCapabilities(name="Planner")],
+        budgets=ResourceBudgets(cpu_cores=1.0, memory_gb=1.0, energy_wh=50.0, time_seconds=600),
+        data_policy=DataSharingPolicy(policy_id="p1", allowed_data=["telemetry"]),
+    )
+
+    plan = {"name": "demo-plan", "actions": ["a1", "a2"], "budgets": {"cpu_cores": 0.5}}
+
+    out = run_demo(contract, plan)
+
+    assert "certificate" in out
+    assert "ledger_entry" in out
+    assert out["certificate"]["status"] in ("safe", "unsafe")
+    # chain should contain one entry
+    assert isinstance(out["chain"], list)
+    assert len(out["chain"]) == 1