diff --git a/src/config.rs b/src/config.rs
index 296e0b0..5484efa 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -126,13 +126,13 @@ fn build_config_std() -> Config {
                      suffix: env::var("INPUT_GUI_PRESS_SUFFIX").unwrap_or(String::from("")),
                   },
                   release: PreSufFix{
-                     prefix: env::var("INPUT_GUI_RELEASE_PREFIX").unwrap_or(String::from("!")),
+                     prefix: env::var("INPUT_GUI_RELEASE_PREFIX").unwrap_or(String::from("")),
                      suffix: env::var("INPUT_GUI_RELEASE_SUFFIX").unwrap_or(String::from("")),
                   },
                   format: match env::var("INPUT_GUI_FORMAT") {
                      Ok(x) => Some(x),
                      Err(_) => match env::var("INPUT_GUI_FORMAT_V01").unwrap_or(String::from("false")) == String::from("true") {
-                        true => Some(String::from("TODO")),
+                        true => Some(String::from("{\"T\":{{ms}},\"U\":\"{{user}}\",\"Y\":\"{{pressed}}\",\"N\":\"{{released}}\"}")),
                         false => None,
                      },
                   },
diff --git a/src/gui.rs b/src/gui.rs
index cbdef09..2295d51 100644
--- a/src/gui.rs
+++ b/src/gui.rs
@@ -5,6 +5,7 @@ use iced::subscription;
 use iced::{Alignment, Element, Application, Settings, Subscription, Theme, Command};
 use iced_futures::backend::native::async_std::time::every;
 use handlebars::Handlebars;
+use serde_json::json;
 use std::time::{SystemTime, UNIX_EPOCH};
 
 use crate::stream::OutputStream;
@@ -117,28 +118,49 @@ impl Main {
             None => {},
          };
       }
+      let mut t = vec![];
       self.keys_newly_down.clear();
       for key_code in self.keys_up.iter() {
          match self.key_code_to_string(key_code) {
             Some(x) => {
                for c in x.chars() {
                   for c in self.flags.cfg.release.prefix.chars() {
-                     s.push(c);
+                     t.push(c);
                   }
-                  s.push(c);
+                  t.push(c);
                   for c in self.flags.cfg.release.suffix.chars() {
-                     s.push(c);
+                     t.push(c);
                   }
                }
             },
             None => {},
          };
       }
-      if s.len() > 0 {
-         self.flags.output_stream.put(s);
+      if t.len() + s.len() > 0 {
+         self.flags.output_stream.put(self.sprintf(s, t));
       }
       self.keys_up.clear();
    }
+
+   fn sprintf(&self, pressed: Vec<char>, released: Vec<char>) -> Vec<char> {
+      match self.flags.cfg.format.clone() {
+         Some(x) => {
+            let reg = Handlebars::new();
+            return reg.render_template(&x, &json!({
+               "pressed": pressed.iter().collect::<String>(),
+               "released": released.iter().collect::<String>(),
+               "ms": SystemTime::now().duration_since(UNIX_EPOCH).unwrap().as_millis(),
+               "user": String::from(""),
+            })).unwrap().chars().collect();
+         },
+         None => {
+            let mut combo = vec![];
+            combo.extend(pressed);
+            combo.extend(released);
+            return combo;
+         },
+      }
+   }
 }
 
 impl Application for Main {