diff --git a/src/cli.rs b/src/cli.rs
deleted file mode 100644
index e69de29..0000000
diff --git a/src/commands/add.rs b/src/commands/add.rs
deleted file mode 100644
index e69de29..0000000
diff --git a/src/commands/delete.rs b/src/commands/delete.rs
deleted file mode 100644
index e69de29..0000000
diff --git a/src/commands/list.rs b/src/commands/list.rs
deleted file mode 100644
index e69de29..0000000
diff --git a/src/commands/update.rs b/src/commands/update.rs
deleted file mode 100644
index e69de29..0000000
diff --git a/src/main.rs b/src/main.rs
index ad107ff..8ddad01 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,149 @@
 mod task;
-fn main() {
-    let t = task::Task::from_string("1. [>] \"Task 1\"; due: 2020-01-21T00:00; priority: 1; tags: tag1, tag2".to_string()).unwrap();
-    let is_valid = t.validate();
-    println!("{}", is_valid);
-    println!("{}", t);
+mod storage;
+use clap::{Args, Parser, Subcommand};
+
+#[derive(Parser)]
+#[command(name = "citrine", version = "0.1.0")]
+#[command(author = "syntaxbullet <syntaxbullet@protonmail.com>")]
+#[command(about = "A simple task manager following the unix philosophy")]
+
+pub struct Cli {
+    #[command(subcommand)]
+    command: Option<Commands>,
+}
+
+#[derive(Subcommand)]
+
+enum Commands {
+    Add(Add),
+    Update(Update),
+    Delete(Delete),
+    List(List),
+}
+
+#[derive(Args)]
+/// Add a new task to the task list
+struct Add {
+    /// The title of the task
+    title: String,
+    /// The due date of the task in rfc3339 format (e.g. 2021-01-01T00:00:00+00:00)
+    #[arg(short = 'd', long = "due")]
+    due_date: Option<String>,
+    /// The priority of the task [0-9]
+    #[arg(short = 'p', long = "priority")]
+    priority: Option<u8>,
+    /// The tags of the task , must be a comma separated list
+    #[arg(short = 't', long = "tags")]
+    tags: Option<Vec<String>>,
 }
+#[derive(Args)]
+/// Update an existing task in the task list
+struct Update {
+    /// The id of the task to update
+    id: u8,
+    /// The due date of the task in rfc3339 format (e.g. 2021-01-01T00:00:00+00:00)
+    #[arg(short = 'd', long = "due")]
+    due_date: Option<String>,
+    /// The priority of the task (0-9)
+    #[arg(short = 'p', long = "priority")]
+    priority: Option<u8>,
+    /// The tags of the task, must be a comma separated list
+    #[arg(short = 't', long = "tags")]
+    tags: Option<Vec<String>>,
+    /// The status of the task
+    #[arg(short = 's', long = "status")]
+    status: Option<String>,
+    /// The title of the task
+    #[arg(short = 'm', long = "message")]
+    title: Option<String>,
+    /// remove tags from the task
+    #[arg(short = 'r', long = "remove-tags")]
+    remove_tag: Option<String>,
+    /// append tags to the task
+    #[arg(short = 'a', long = "append-tags")]
+    append_tag: Option<String>,
+}
+
+#[derive(Args)]
+/// Delete an existing task from the task list
+struct Delete {
+    /// The id of the task to remove
+    id: u8,
+}
+
+#[derive(Args)]
+/// List all tasks in the task list filtered by the given options
+struct List {}
+
+fn main() {
+    let cli = Cli::parse();
+
+    match cli.command {
+        Some(Commands::Add(add)) => {
+            let last_id = storage::get_last_id().unwrap_or(0);
+            let task = task::Task {
+                id: last_id + 1,
+                title: add.title,
+                status: ' ',
+                due_date: add.due_date,
+                priority: add.priority,
+                tags: add.tags.unwrap_or(Vec::new()),
+            };
+            // validate the task
+            if !task.validate() {
+                println!("Invalid task");
+                return;
+            }
+            // append the task to the task list
+            storage::append_task(task).unwrap();
+
+
+        }
+        Some(Commands::Update(update)) => {
+            // get the task to update
+            let mut task = storage::read_task(update.id).unwrap();
+            // update the task
+            if let Some(due_date) = update.due_date {
+                task.due_date = Some(due_date);
+            }
+            if let Some(priority) = update.priority {
+                task.priority = Some(priority);
+            }
+            if let Some(status) = update.status {
+                task.status = status.chars().next().unwrap();
+            }
+            if let Some(title) = update.title {
+                task.title = title;
+            }
+            if let Some(append_tag) = update.append_tag {
+                task.tags.push(append_tag);
+            }
+            if let Some(remove_tag) = update.remove_tag {
+                task.tags.retain(|tag| tag != &remove_tag);
+            }
+            // validate the task
+            if !task.validate() {
+                println!("Invalid task");
+                return;
+            }
+            // update the task in the task list
+            storage::update_task(update.id, task).unwrap();
+
+        }
+        Some(Commands::Delete(delete)) => {
+            // delete the task from the task list
+            storage::delete_task(delete.id).unwrap();
+        }
+        Some(Commands::List(_list)) => {
+            // get all tasks from the task list
+            let tasks = storage::read_tasks().unwrap();
+            // print all tasks
+            for task in tasks {
+                println!("{}", task);
+            }
+        }
+        None => {
+            println!("No command given");
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/storage.rs b/src/storage.rs
index e69de29..fb462a6 100644
--- a/src/storage.rs
+++ b/src/storage.rs
@@ -0,0 +1,84 @@
+
+use std::error::Error;
+use std::fs::{File, OpenOptions};
+
+use crate::task::Task;
+use std::io::Write;
+use std::io::Read;
+
+pub fn append_task(task: Task) -> Result<(), Box<dyn Error>> {
+    let mut file = OpenOptions::new()
+        .append(true)
+        .create(true)
+        .open(".citrine")?;
+    // validate the task
+    if !task.validate() {
+        println!("Invalid task");
+        return Ok(());
+    }
+    writeln!(file, "{}", task)?;
+    Ok(())
+}
+pub fn read_task(id: u8) -> Result<Task, Box<dyn Error>> {
+    let mut file = File::open(".citrine")?;
+    let mut contents = String::new();
+    file.read_to_string(&mut contents)?;
+    for line in contents.lines() {
+        let task = Task::from_string(line.to_string()).unwrap();
+        if task.id == id {
+            return Ok(task);
+        }
+    }
+    Err("Task not found".into())
+}
+pub fn read_tasks() -> Result<Vec<Task>, Box<dyn Error>> {
+    let mut file = File::open(".citrine")?;
+    // if the file is empty, return an empty vector
+    if file.metadata()?.len() == 0 {
+        return Ok(Vec::new());
+    }
+    // if the file does not exist, return an empty vector
+    if !std::path::Path::new(".citrine").exists() {
+        return Ok(Vec::new());
+    }
+    let mut contents = String::new();
+    file.read_to_string(&mut contents)?;
+    let mut tasks = Vec::new();
+    for line in contents.lines() {
+        // skip unparseable lines
+        if let Some(task) = Task::from_string(line.to_string()) {
+            tasks.push(task);
+        }
+    }
+    Ok(tasks)
+}
+pub fn write_tasks(tasks: Vec<Task>) -> Result<(), Box<dyn Error>> {
+    let mut file = File::create(".citrine")?;
+    for task in tasks {
+        writeln!(file, "{}", task)?;
+    }
+    Ok(())
+}
+pub fn delete_task(id: u8) -> Result<(), Box<dyn Error>> {
+    let mut tasks = read_tasks()?;
+    tasks.retain(|task| task.id != id);
+    write_tasks(tasks)?;
+    Ok(())
+}
+pub fn update_task(id: u8, task: Task) -> Result<(), Box<dyn Error>> {
+    let mut tasks = read_tasks()?;
+    tasks.retain(|t| t.id != id);
+    tasks.push(task);
+    write_tasks(tasks)?;
+    Ok(())
+}
+pub fn get_last_id() -> Result<u8, Box<dyn Error>> {
+    let tasks = read_tasks()?;
+    let mut last_id = 0;
+    for task in tasks {
+        if task.id > last_id {
+            last_id = task.id;
+        }
+    }
+    Ok(last_id)
+}
diff --git a/src/task.rs b/src/task.rs
index 1c9d192..8d34bab 100644
--- a/src/task.rs
+++ b/src/task.rs
@@ -74,6 +74,10 @@ impl Task {
                 _ => (),
             }
         }
+        // validate the task
+        if !result.validate() {
+            return None;
+        }
         Some(result)
     }
     pub fn validate(&self) -> bool {
diff --git a/src/utils.rs b/src/utils.rs
deleted file mode 100644
index e69de29..0000000