diff --git a/schema.graphqls b/schema.graphqls
index f874943..0dcd118 100644
--- a/schema.graphqls
+++ b/schema.graphqls
@@ -65,21 +65,29 @@ type Query {
   systems: [System!]!
   system(id: ID): System
 
-  isNotificationScheduled(input: NotificationInput!): Boolean
+  isNotificationScheduled(input: NotificationLookupArguments!): Boolean
+  secondsThresholdForNotification(input: NotificationLookupArguments!): Int
 }
 
 # Mutations
 type Mutation {
-  scheduleNotification(input: NotificationInput!): NotificationResponse!
-  cancelNotification(input: NotificationInput!): NotificationResponse!
+  scheduleNotification(input: NotificationSchedulingArguments!): NotificationResponse!
+  cancelNotification(input: NotificationLookupArguments!): NotificationResponse!
 }
 
-input NotificationInput {
+input NotificationLookupArguments {
   deviceId: ID!
   shuttleId: ID!
   stopId: ID!
 }
 
+input NotificationSchedulingArguments {
+  deviceId: ID!
+  shuttleId: ID!
+  stopId: ID!
+  secondsThreshold: Int
+}
+
 type NotificationResponse {
   success: Boolean!
   message: String!
@@ -90,4 +98,5 @@ type Notification {
   deviceId: ID!
   shuttleId: ID!
   stopId: ID!
+  secondsThreshold: Int
 }