diff --git a/src/models/process.model.ts b/src/models/process.model.ts
index 06b4958..f6faa6c 100755
--- a/src/models/process.model.ts
+++ b/src/models/process.model.ts
@@ -48,4 +48,9 @@ export enum MessageType {
   UPDATE_NOTIFIED = 'UPDATE_NOTIFIED',
   VALIDATE_STATE = 'VALIDATE_STATE',
   STATE_VALIDATED = 'STATE_VALIDATED',
+  // Hash and merkle proof
+  HASH_VALUE = 'HASH_VALUE',
+  VALUE_HASHED = 'VALUE_HASHED',
+  GET_MERKLE_PROOF = 'GET_MERKLE_PROOF',
+  MERKLE_PROOF_RETRIEVED = 'MERKLE_PROOF_RETRIEVED',
 }