diff --git a/app/main.py b/app/main.py
index 8326d1d..83a7800 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1,10 +1,53 @@
 # app/main.py
+import logging
+from telegram import Update
+from telegram.ext import Application, CommandHandler, CallbackQueryHandler, ContextTypes
 
-def main():
-    """
-    Main function to run the bot.
-    """
-    print("Talía Bot is running...")
+from config import TELEGRAM_BOT_TOKEN
+from permissions import get_user_role
+from modules.onboarding import handle_start as onboarding_handle_start
+
+# Enable logging
+logging.basicConfig(
+    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s", level=logging.INFO
+)
+logger = logging.getLogger(__name__)
+
+async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Sends a welcome message and menu when the /start command is issued."""
+    chat_id = update.effective_chat.id
+    user_role = get_user_role(chat_id)
+
+    logger.info(f"User {chat_id} started conversation with role: {user_role}")
+
+    # Delegate to the onboarding module
+    response_text, reply_markup = onboarding_handle_start(user_role)
+
+    await update.message.reply_text(response_text, reply_markup=reply_markup)
+
+async def button(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Parses the CallbackQuery and updates the message text."""
+    query = update.callback_query
+    await query.answer()
+    # TODO: Implement handlers for the different callback queries
+    await query.edit_message_text(text=f"Selected option: {query.data}")
+
+def main() -> None:
+    """Start the bot."""
+    if not TELEGRAM_BOT_TOKEN:
+        logger.error("TELEGRAM_BOT_TOKEN is not set in the environment variables.")
+        return
+
+    # Create the Application and pass it your bot's token.
+    application = Application.builder().token(TELEGRAM_BOT_TOKEN).build()
+
+    # Add command handlers
+    application.add_handler(CommandHandler("start", start))
+    application.add_handler(CallbackQueryHandler(button))
+
+    # Run the bot until the user presses Ctrl-C
+    logger.info("Starting Talía Bot...")
+    application.run_polling()
 
 if __name__ == "__main__":
     main()
diff --git a/app/modules/onboarding.py b/app/modules/onboarding.py
index d4c163a..a2097e4 100644
--- a/app/modules/onboarding.py
+++ b/app/modules/onboarding.py
@@ -1,9 +1,42 @@
 # app/modules/onboarding.py
+from telegram import InlineKeyboardButton, InlineKeyboardMarkup
 
-def handle_start(chat_id):
+def get_owner_menu():
+    """Returns the main menu for the owner."""
+    keyboard = [
+        [InlineKeyboardButton("📅 Ver mi agenda", callback_data='view_agenda')],
+        [InlineKeyboardButton("⏳ Ver pendientes", callback_data='view_pending')],
+        [InlineKeyboardButton("✅ Aprobar solicitud", callback_data='approve_request')],
+    ]
+    return InlineKeyboardMarkup(keyboard)
+
+def get_team_menu():
+    """Returns the main menu for a team member."""
+    keyboard = [
+        [InlineKeyboardButton("🕒 Proponer actividad", callback_data='propose_activity')],
+        [InlineKeyboardButton("📄 Ver estatus de solicitudes", callback_data='view_requests_status')],
+    ]
+    return InlineKeyboardMarkup(keyboard)
+
+def get_client_menu():
+    """Returns the main menu for a client."""
+    keyboard = [
+        [InlineKeyboardButton("🗓️ Agendar una cita", callback_data='schedule_appointment')],
+        [InlineKeyboardButton("ℹ️ Información de servicios", callback_data='get_service_info')],
+    ]
+    return InlineKeyboardMarkup(keyboard)
+
+def handle_start(user_role):
     """
-    Handles the /start command and sends a welcome message.
+    Handles the /start command and sends a role-based welcome message and menu.
     """
-    print(f"[{chat_id}] Handling start command...")
-    # TODO: Implement welcome message and main menu
-    return "Welcome to Talía!"
+    welcome_message = "Hola, soy Talía. ¿En qué puedo ayudarte hoy?"
+
+    if user_role == "owner":
+        menu = get_owner_menu()
+    elif user_role in ["admin", "team"]:
+        menu = get_team_menu()
+    else: # client
+        menu = get_client_menu()
+
+    return welcome_message, menu
diff --git a/tasks.md b/tasks.md
index 2a55428..b13d576 100644
--- a/tasks.md
+++ b/tasks.md
@@ -12,14 +12,14 @@ This file tracks the development tasks for the Talía project.
 
 ## Phase 2: Core Logic Implementation
 
-- [ ] Implement `main.py` as the central orchestrator.
-- [ ] Implement `config.py` to handle environment variables.
-- [ ] Implement `permissions.py` for role-based access control.
-- [ ] Implement `webhook_client.py` for n8n communication.
+- [x] Implement `main.py` as the central orchestrator.
+- [x] Implement `config.py` to handle environment variables.
+- [x] Implement `permissions.py` for role-based access control.
+- [x] Implement `webhook_client.py` for n8n communication.
 
 ## Phase 3: Module Implementation
 
-- [ ] Implement `onboarding.py` module.
+- [x] Implement `onboarding.py` module.
 - [ ] Implement `agenda.py` module.
 - [ ] Implement `citas.py` module.
 - [ ] Implement `equipo.py` module.
@@ -39,3 +39,4 @@ This file tracks the development tasks for the Talía project.
 
 - Created `tasks.md` to begin tracking development.
 - Completed initial project scaffolding.
+- Implemented the core logic for the bot, including the central orchestrator, permissions, and onboarding.