diff --git a/README.md b/README.md
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+++ b/README.md
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+# Ajal Todo CLI
+
+A todo utility
diff --git a/todo.py b/todo.py
new file mode 100755
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+++ b/todo.py
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+#!/usr/bin/env python3
+import os
+import re
+import sys
+
+base_dir = os.path.abspath(os.path.dirname(__file__))
+todo_file = os.path.join(base_dir, "todo.md")
+
+
+def add_task(task: str, parent=None):
+    print(f"Adding task '{task}' to '{parent if parent else 'root'}'")
+    todo = parse_todo()
+    if parent and parent not in todo:
+        print(f"Could not find parent task '{parent}' in root task list")
+        exit(1)
+    if parent:
+        todo[parent]["sub_tasks"][task] = {"completed": False}
+    else:
+        todo[task] = {"completed": False, "sub_tasks": {}}
+    write_todo(todo)
+
+
+def list_tasks(parent=None):
+    print(f"Listing tasks in '{parent if parent else 'root'}'")
+    todo = parse_todo()
+    if parent and parent not in todo:
+        print(f"Could not find parent task '{parent}' in root task list")
+        exit(1)
+    if parent:
+        todo = {parent: todo[parent]}
+    print(build_todo(todo))
+
+
+def complete_task(task, parent=None):
+    print(f"Marking task '{task}' in '{parent if parent else 'root'}' as completed")
+    todo = parse_todo()
+    if parent:
+        if parent not in todo:
+            print(f"Could not find parent task '{parent}' in root task list")
+            exit(1)
+        if task not in todo[parent]["sub_tasks"]:
+            print(f"Could not find task '{task}' in parent task '{parent}'")
+            exit(1)
+    if task not in todo:
+        print(f"Could not find task '{task}' in root task list")
+        exit(1)
+    if parent:
+        task = todo[parent]["sub_tasks"][task]
+    else:
+        task = todo[task]
+    task["completed"] = True
+    write_todo(todo)
+
+
+def remove_task(task, parent=None):
+    print(f"Removing task '{task}' from '{parent if parent else 'root'}'")
+    todo = parse_todo()
+    if parent:
+        if parent not in todo:
+            print(f"Could not find parent task '{parent}' in root task list")
+            exit(1)
+        if task not in todo[parent]["sub_tasks"]:
+            print(f"Could not find task '{task}' in parent task '{parent}'")
+            exit(1)
+    if task not in todo:
+        print(f"Could not find task '{task}' in root task list")
+        exit(1)
+    if parent:
+        del todo[parent]["sub_tasks"][task]
+    else:
+        del todo[task]
+    write_todo(todo)
+
+
+def print_help():
+    print("""Usage: todo.py [add|complete|remove] TASK [PARENT]
+       todo.py list PARENT
+
+    Manages todo.md file as a ToDo file""")
+
+
+def parse_todo() -> dict[str, dict]:
+    todo = {}
+    with open(todo_file, "r") as f:
+        lines = f.readlines()
+        root_task = None
+        for line in lines:
+            if matches := re.match(r"^-\s+(\[(?P<status>[x ])]\s+)?(?P<task>.*)$", line.rstrip()):
+                root_task_name = matches.group("task")
+                root_task = {
+                    "completed": matches.group("status") == "x",
+                    "sub_tasks": {},
+                }
+                todo[root_task_name] = root_task
+            elif matches := re.match(r"^\s+-\s+(\[(?P<status>[x ])]\s+)?(?P<task>.*)$", line.rstrip()):
+                leaf_task = matches.group("task")
+                root_task["sub_tasks"][leaf_task] = {
+                    "completed": matches.group("status") == "x",
+                }
+    return todo
+
+
+def build_todo(todo: dict[str, dict]) -> str:
+    lines = ["# A ToDo list", ""]
+    for task, task_data in todo.items():  # type: str, dict
+        lines.append(f"- [{'x' if task_data["completed"] else ' '}] {task}")
+        for leaf_task, leaf_task_data in task_data["sub_tasks"].items():
+            lines.append(f"  - [{'x' if leaf_task_data["completed"] else ' '}] {leaf_task}")
+    lines += [""]
+    return "\n".join(lines)
+
+
+def write_todo(todo: dict[str, dict]):
+    with open(todo_file, "w") as f:
+        f.write(build_todo(todo))
+
+
+def main():
+    if len(sys.argv) < 2:
+        print_help()
+        exit(1)
+
+    match sys.argv[1]:
+        case "help" | "--help" | "h" | "-h":
+            print_help()
+        case "list":
+            match sys.argv[2:]:
+                case [parent]:
+                    list_tasks(parent)
+                case _:
+                    list_tasks()
+        case "add" | "complete" | "remove" as task_name:
+            task_func = f"{task_name}_task"
+            match sys.argv[2:]:
+                case [task]:
+                    globals()[task_func](task)
+                case [task, parent]:
+                    globals()[task_func](task, parent)
+                case _:
+                    print_help()
+                    exit(1)
+        case _:
+            print_help()
+            exit(1)
+
+
+if __name__ == "__main__":
+    main()