diff --git a/src/booking_service.v b/src/booking_service.v
index e001cc0..4f69500 100644
--- a/src/booking_service.v
+++ b/src/booking_service.v
@@ -2,6 +2,7 @@ module main
 
 import time
 
+// service_add_booking is a function that adds a new booking to the database.
 fn (app &App) service_add_booking(name string, user_id int, flight_id int) ! {
 	booking := Booking{
 		name:       name
@@ -16,6 +17,7 @@ fn (app &App) service_add_booking(name string, user_id int, flight_id int) ! {
 	}!
 }
 
+// service_get_user_bookings is a function that retrieves all bookings for a given user.
 fn (app &App) service_get_user_bookings(user_id int) ![]Booking {
 	bookings := sql app.db {
 		select from Booking where user_id == user_id order by created_at desc
@@ -24,6 +26,7 @@ fn (app &App) service_get_user_bookings(user_id int) ![]Booking {
 	return bookings
 }
 
+// service_cancel_booking is a function that cancels a booking.
 fn (app &App) service_cancel_booking(id int) ! {
 	booking := app.service_get_booking(id) or { return error('Booking not found') }
 
@@ -36,6 +39,7 @@ fn (app &App) service_cancel_booking(id int) ! {
 	}!
 }
 
+// service_get_booking is a function that retrieves a booking by its ID.
 fn (app &App) service_get_booking(id int) !Booking {
 	booking := sql app.db {
 		select from Booking where id == id
diff --git a/src/flight_service.v b/src/flight_service.v
index 2e2a95a..fcf4119 100644
--- a/src/flight_service.v
+++ b/src/flight_service.v
@@ -2,6 +2,7 @@ module main
 
 import time
 
+// service_add_flight is a function that adds a new flight to the database.
 fn (app &App) service_add_flight(from string, to string, departure time.Time, price int) !Flight {
 	flight_model := Flight{
 		from:       from
@@ -24,6 +25,7 @@ fn (app &App) service_add_flight(from string, to string, departure time.Time, pr
 	return flight[0]
 }
 
+// service_get_flight is a function that retrieves a flight by its ID.
 fn (app &App) service_get_flight(id int) !Flight {
 	flight := sql app.db {
 		select from Flight where id == id
diff --git a/src/user_service.v b/src/user_service.v
index 6d0208d..4902af9 100644
--- a/src/user_service.v
+++ b/src/user_service.v
@@ -2,6 +2,7 @@ module main
 
 import veb.auth
 
+// service_add_user is a function that adds a new user to the database.
 fn (app &App) service_add_user(first_name string, last_name string, email string, password string, gender string) ! {
 	salt := auth.generate_salt()
 
@@ -23,6 +24,7 @@ fn (app &App) service_add_user(first_name string, last_name string, email string
 	}
 }
 
+// service_find_user_by_email is a function that finds a user by their email address.
 fn (app &App) service_find_user_by_email(email string, password string) !User {
 	mut user := sql app.db {
 		select from User where email == email
@@ -36,6 +38,7 @@ fn (app &App) service_find_user_by_email(email string, password string) !User {
 	return user[0]
 }
 
+// service_update_user is a function that updates a user's information.
 fn (app &App) service_update_user(id ?string, first_name string, last_name string, password string) ! {
 	if id == none {
 		return error('User ID is required')
@@ -75,6 +78,7 @@ fn (app &App) service_update_user(id ?string, first_name string, last_name strin
 	return
 }
 
+// service_get_user is a function that retrieves a user's information.
 fn (app &App) service_get_user(id int) !User {
 	if id == 0 {
 		return error('User ID is required')