diff --git a/src/algograph_algebraic_portfolio_compiler_f/registry.py b/src/algograph_algebraic_portfolio_compiler_f/registry.py
index bdb98ff..208430d 100644
--- a/src/algograph_algebraic_portfolio_compiler_f/registry.py
+++ b/src/algograph_algebraic_portfolio_compiler_f/registry.py
@@ -3,6 +3,8 @@ from __future__ import annotations
 from dataclasses import dataclass, field
 from typing import Dict, List, Optional, Any
 import time
+import json
+import hashlib
 
 
 @dataclass
@@ -58,5 +60,30 @@ class GraphOfContractsRegistry:
             raise KeyError(f"Contract {contract_id} not found")
         rec.attestations.append(attestation)
 
+    def generate_attestation(self, contract_id: str) -> str:
+        """Create a deterministic SHA-256 attestation for a registered contract.
+
+        The attestation is computed over a canonical JSON serialization of the
+        contract metadata (name, version, contract_id, schema, signer, timestamp)
+        to ensure repeatability for audits and replay checks.
+        """
+        rec = self.contracts.get(contract_id)
+        if rec is None:
+            raise KeyError(f"Contract {contract_id} not found")
+        # Canonical JSON serialization for deterministic hashing
+        payload = {
+            "name": rec.name,
+            "version": rec.version,
+            "contract_id": rec.contract_id,
+            "schema": rec.schema,
+            "signer": rec.signer,
+            "timestamp": rec.timestamp,
+        }
+        data = json.dumps(payload, sort_keys=True, separators=(",", ":")).encode("utf-8")
+        h = hashlib.sha256(data).hexdigest()
+        att = f"sha256:{h}"
+        rec.attestations.append(att)
+        return att
+
 
 __all__ = ["ContractRecord", "GraphOfContractsRegistry"]
diff --git a/tests/test_registry.py b/tests/test_registry.py
index 226c26f..6e2e099 100644
--- a/tests/test_registry.py
+++ b/tests/test_registry.py
@@ -18,3 +18,8 @@ def test_registry_basic_operations():
     assert c.name == "toyAdapter"
     reg.add_attestation("idea-1", "attestation-123")
     assert reg.get_contract("idea-1").attestations[-1] == "attestation-123"
+    # generate deterministic sha256 attestation and ensure it's appended
+    att = reg.generate_attestation("idea-1")
+    assert isinstance(att, str)
+    assert att.startswith("sha256:")
+    assert reg.get_contract("idea-1").attestations[-1] == att