diff --git a/src/api.rs b/src/api.rs
index 93ba732..3509d05 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -905,38 +905,59 @@ fn handle_prd(
             });
         }
         PrdType::Response => {
-            let mut to_update = relevant_process
-                .get_latest_concurrent_states_mut()?
-                .into_iter()
-                .find(|r| {
-                    r.pcd_commitment == prd.pcd_commitments
-                })
-                .ok_or(anyhow::Error::msg("Original request not found"))?;
+            let update_state_id = prd.pcd_commitments.create_merkle_tree()?.root().ok_or(AnyhowError::msg("Invalid merkle tree"))?.to_lower_hex_string();
+            let mut to_update = relevant_process.get_state_for_id_mut(&update_state_id)?;
 
-            to_update
-                .validation_tokens
-                .extend(prd.validation_tokens);
+            let new_validations = prd.validation_tokens;
+            let mut to_add: Vec<&Proof> = vec![];
+
+            for token in &new_validations {
+                let key = token.get_key();
+
+                // Check if the token key already exists
+                let already_exists = to_update
+                    .validation_tokens
+                    .iter()
+                    .any(|existing_token| existing_token.get_key() == key);
+
+                if !already_exists {
+                    debug!("Adding token with key {}", key);
+                    to_add.push(token);
+                } else {
+                    debug!("Token with key {} already exists, skipping", key);
+                }
+            }
+
+            // If there's no new proofs return early
+            if to_add.is_empty() {
+                return Err(AnyhowError::msg("No new validation tokens found in prd response"));
+            }
+
+            // We add the new tokens and return all that was updated
+            to_update.validation_tokens.extend(to_add);
 
             let updated_state = to_update.clone();
 
             let clear_state = to_update.decrypt_pcd()?;
 
             let roles = Value::Object(clear_state).extract_roles()?;
+            let modified_state = Some(to_update.state_id.clone());
+            let mut commit_msg = CommitMessage::new_update_commitment(
+                OutPoint::from_str(&prd.root_commitment)?, 
+                updated_state.pcd_commitment, 
+                roles
+            );
+
+            commit_msg.set_validation_tokens(updated_state.validation_tokens);
 
             // We must return an update of the process
             let updated_process = UpdatedProcess {
                 commitment_tx: OutPoint::from_str(&prd.root_commitment)?,
                 current_process: relevant_process.clone(),
-                modified_state: Some(updated_state.state_id),
+                modified_state,
                 ..Default::default()
             };
 
-            let commit_msg = CommitMessage::new_update_commitment(
-                OutPoint::from_str(&prd.root_commitment)?, 
-                updated_state.pcd_commitment, 
-                roles
-            );
-
             return Ok(ApiReturn {
                 updated_process: Some(updated_process),
                 commit_to_send: Some(commit_msg),
@@ -1359,7 +1380,7 @@ pub fn create_update_message(
 
     let full_prd = Prd::new_update(
         outpoint,
-        serde_json::to_string(&sender)?,
+        sender,
         roles,
         update_state.keys.clone(),
         update_state.pcd_commitment.clone(),
@@ -1522,7 +1543,7 @@ pub fn create_response_prd(init_commitment: String, merkle_root_hex: String) ->
 
     let response_prd = Prd::new_response(
         outpoint,
-        serde_json::to_string(&sender)?,
+        sender,
         vec![*proof], 
         update_state.pcd_commitment.clone(),
     );