diff --git a/src/notifications/schedulers/ETANotificationScheduler.ts b/src/notifications/schedulers/ETANotificationScheduler.ts
index 85e911f..0319cf7 100644
--- a/src/notifications/schedulers/ETANotificationScheduler.ts
+++ b/src/notifications/schedulers/ETANotificationScheduler.ts
@@ -2,10 +2,7 @@ import { ShuttleGetterRepository } from "../../repositories/ShuttleGetterReposit
 import { TupleKey } from "../../types/TupleKey";
 import { IEta } from "../../entities/entities";
 import { AppleNotificationSender, NotificationAlertArguments } from "../senders/AppleNotificationSender";
-import {
-  NotificationLookupArguments,
-  ScheduledNotification
-} from "../../repositories/NotificationRepository";
+import { NotificationLookupArguments, ScheduledNotification } from "../../repositories/NotificationRepository";
 
 type DeviceIdSecondsThresholdAssociation = { [key: string]: number };
 
diff --git a/src/repositories/InMemoryNotificationRepository.ts b/src/repositories/InMemoryNotificationRepository.ts
new file mode 100644
index 0000000..c660ca7
--- /dev/null
+++ b/src/repositories/InMemoryNotificationRepository.ts
@@ -0,0 +1,19 @@
+import { NotificationLookupArguments, NotificationRepository, ScheduledNotification } from "./NotificationRepository";
+
+export class InMemoryNotificationRepository implements NotificationRepository {
+  async getAllNotificationsForShuttleAndStopId(shuttleId: string, stopId: string) {
+    return [];
+  }
+
+  async getSecondsThresholdForNotificationIfExists(lookupArguments: NotificationLookupArguments) {
+    return 0;
+  }
+
+  async addOrUpdateNotification(notification: ScheduledNotification) {
+
+  }
+
+  async deleteNotificationIfExists(lookupArguments: NotificationLookupArguments) {
+
+  }
+}
diff --git a/src/repositories/NotificationRepository.ts b/src/repositories/NotificationRepository.ts
index 7f74914..3787f3d 100644
--- a/src/repositories/NotificationRepository.ts
+++ b/src/repositories/NotificationRepository.ts
@@ -14,20 +14,9 @@ export interface ScheduledNotification extends NotificationLookupArguments {
   secondsThreshold: number;
 }
 
-export class NotificationRepository {
-  public async getAllNotificationsForShuttleAndStopId(shuttleId: string, stopId: string) {
-
-  }
-
-  public async getSecondsThresholdForNotificationIfExists(lookupArguments: NotificationLookupArguments) {
-
-  }
-
-  public async addOrUpdateNotification(notification: ScheduledNotification) {
-
-  }
-
-  public async deleteNotificationIfExists(lookupArguments: NotificationLookupArguments) {
-
-  }
+export interface NotificationRepository {
+  getAllNotificationsForShuttleAndStopId(shuttleId: string, stopId: string): Promise<ScheduledNotification[]>;
+  getSecondsThresholdForNotificationIfExists(lookupArguments: NotificationLookupArguments): Promise<number>;
+  addOrUpdateNotification(notification: ScheduledNotification): Promise<void>;
+  deleteNotificationIfExists(lookupArguments: NotificationLookupArguments): Promise<void>;
 }
diff --git a/src/resolvers/MutationResolvers.ts b/src/resolvers/MutationResolvers.ts
index f512ed5..a840817 100644
--- a/src/resolvers/MutationResolvers.ts
+++ b/src/resolvers/MutationResolvers.ts
@@ -2,8 +2,8 @@ import { NotificationResponse, Resolvers } from "../generated/graphql";
 import { ServerContext } from "../ServerContext";
 import {
   ETANotificationScheduler,
-  ScheduledNotification
 } from "../notifications/schedulers/ETANotificationScheduler";
+import { ScheduledNotification } from "../repositories/NotificationRepository";
 
 export const MutationResolvers: Resolvers<ServerContext> = {
   Mutation: {
@@ -23,7 +23,7 @@ export const MutationResolvers: Resolvers<ServerContext> = {
         }
       }
 
-      const notificationData: NotificationSchedulingArguments = {
+      const notificationData: ScheduledNotification = {
         ...args.input,
         secondsThreshold: typeof args.input.secondsThreshold === 'number'
           ? args.input.secondsThreshold
diff --git a/test/repositories/NotificationRepositoryTests.test.ts b/test/repositories/NotificationRepositoryTests.test.ts
index 9bbe38c..3d4f18b 100644
--- a/test/repositories/NotificationRepositoryTests.test.ts
+++ b/test/repositories/NotificationRepositoryTests.test.ts
@@ -1,6 +1,6 @@
 import { describe, it } from "@jest/globals";
 
-describe("NotificationRepository", () => {
+describe("InMemoryNotificationRepository", () => {
   describe("getAllNotificationsForShuttleAndStopId", () => {
     it("gets notifications correctly", async () => {