diff --git a/src/endpoints/quests/verify_contract.rs b/src/endpoints/quests/verify_contract.rs
index 78fde32c..e82e4545 100644
--- a/src/endpoints/quests/verify_contract.rs
+++ b/src/endpoints/quests/verify_contract.rs
@@ -19,6 +19,7 @@ use starknet::{
     providers::Provider,
 };
 use regex::Regex;
+use crate::utils::parse_string;
 
 #[derive(Debug, Serialize, Deserialize, Default)]
 pub struct VerifyContractQuery {
@@ -39,23 +40,24 @@ pub async fn handler(
         Ok(None) => return get_error("Task not found".to_string()),
         Err(e) => return get_error(format!("Database error: {}", e)),
     };
-
     if task.task_type != Some("contract".to_string()) {
         return get_error("Invalid task type.".to_string());
     }
 
     let addr = &query.addr;
-    
     if let Some(calls) = task.calls {
         for call in calls {
             let contract_address = match FieldElement::from_hex_be(&call.contract) {
                 Ok(address) => address,
                 Err(e) => return get_error(format!("Invalid contract address: {}", e)),
             };
-            
+
             let calldata: Vec<FieldElement> = match call.call_data
                 .iter()
-                .map(|s| FieldElement::from_hex_be(s))
+                .map(|s| {
+                    let replaced_calldata = parse_string(s, FieldElement::from_hex_be(s).unwrap());
+                    FieldElement::from_hex_be(&replaced_calldata)
+                })
                 .collect::<Result<Vec<FieldElement>, _>>()
             {
                 Ok(data) => data,
@@ -81,12 +83,13 @@ pub async fn handler(
 
             match call_result {
                 Ok(result) => {
-                    let regex = match Regex::new(&call.regex) {
+                    let regex_str = parse_string(&call.regex, FieldElement::from_hex_be(&call.contract).unwrap());
+                    let regex = match Regex::new(&regex_str) {
                         Ok(re) => re,
                         Err(e) => return get_error(format!("Invalid regex: {}", e)),
                     };
                     let result_str = result.iter().map(|&r| r.to_string()).collect::<Vec<String>>().join(",");
-                    
+
                     if !regex.is_match(&result_str) {
                         return get_error("Contract call result does not match the expected pattern.".to_string());
                     }
diff --git a/src/endpoints/quests/verify_custom_api.rs b/src/endpoints/quests/verify_custom_api.rs
index bda30a19..f94f2bf3 100644
--- a/src/endpoints/quests/verify_custom_api.rs
+++ b/src/endpoints/quests/verify_custom_api.rs
@@ -16,6 +16,7 @@ use serde_json::json;
 use regex::Regex;
 use reqwest::get;
 use starknet::core::types::FieldElement;
+use crate::utils::parse_string;
 
 #[derive(Debug, Serialize, Deserialize, Default)]
 pub struct VerifyCustomApiQuery {
@@ -55,14 +56,17 @@ pub async fn handler(
     };
 
     // Call the specified API
-    let response = get(api_url).await;
+    let parsed_api_url = parse_string(api_url, FieldElement::from_str(&query.addr).unwrap());
+
+    let response = get(&parsed_api_url).await;
 
     match response {
         Ok(res) => {
             let res_text = res.text().await.unwrap();
             
             // Check response against the regex
-            let re = Regex::new(regex_str).unwrap();
+            let parsed_regex_str = parse_string(regex_str, FieldElement::from_str(&query.addr).unwrap());
+            let re = Regex::new(&parsed_regex_str).unwrap();
             if re.is_match(&res_text) {
                 // Mark the task as completed
                 match state.upsert_completed_task(FieldElement::from_str(&query.addr).unwrap(), task_id).await {
diff --git a/src/utils.rs b/src/utils.rs
index 39c2dd6c..72f72667 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -33,6 +33,8 @@ use std::str::FromStr;
 use std::{fmt::Write, sync::Arc};
 use tokio::time::{sleep, Duration};
 
+use regex::Regex;
+
 #[macro_export]
 macro_rules! pub_struct {
     ($($derive:path),*; $name:ident {$($field:ident: $t:ty),* $(,)?}) => {
@@ -830,12 +832,17 @@ impl Clone for Box<dyn WithState> {
 pub fn parse_string(input: &str, address: FieldElement) -> String {
     let mut result = input.to_string();
 
-    if input.contains("{addr_hex}") {
-        result = result.replace("{addr_hex}", to_hex(address).as_str());
-    }
+    let hex_address = to_hex(address);
+    let dec_address = address.to_string();
 
-    if input.contains("{addr_dec}") {
-        result = result.replace("{addr_dec}", address.to_string().as_str());
+    let regex_patterns = vec![
+        (r"\{addr_hex\}", hex_address.as_str()), 
+        (r"\{addr_dec\}", dec_address.as_str()), 
+    ];
+    
+    for (pattern, replacement) in regex_patterns {
+        let re = Regex::new(pattern).unwrap();
+        result = re.replace_all(&result, replacement).to_string();
     }
 
     result