diff --git a/src/abstractions/collection.service.ts b/src/abstractions/collection.service.ts
new file mode 100644
index 0000000000..e33532d3ce
--- /dev/null
+++ b/src/abstractions/collection.service.ts
@@ -0,0 +1,16 @@
+import { CollectionData } from '../models/data/collectionData';
+
+import { Collection } from '../models/domain/collection';
+
+export interface CollectionService {
+    decryptedCollectionCache: any[];
+
+    clearCache(): void;
+    get(id: string): Promise<Collection>;
+    getAll(): Promise<Collection[]>;
+    getAllDecrypted(): Promise<any[]>;
+    upsert(collection: CollectionData | CollectionData[]): Promise<any>;
+    replace(collections: { [id: string]: CollectionData; }): Promise<any>;
+    clear(userId: string): Promise<any>;
+    delete(id: string | string[]): Promise<any>;
+}
diff --git a/src/abstractions/index.ts b/src/abstractions/index.ts
index 7ef441f0c3..893a189120 100644
--- a/src/abstractions/index.ts
+++ b/src/abstractions/index.ts
@@ -1,6 +1,7 @@
 export { ApiService } from './api.service';
 export { AppIdService } from './appId.service';
 export { CipherService } from './cipher.service';
+export { CollectionService } from './collection.service';
 export { CryptoService } from './crypto.service';
 export { EnvironmentService } from './environment.service';
 export { FolderService } from './folder.service';
diff --git a/src/services/collection.service.ts b/src/services/collection.service.ts
new file mode 100644
index 0000000000..c409925cd7
--- /dev/null
+++ b/src/services/collection.service.ts
@@ -0,0 +1,124 @@
+import { CollectionData } from '../models/data/collectionData';
+
+import { Collection } from '../models/domain/collection';
+
+import { CryptoService } from '../abstractions/crypto.service';
+import { StorageService } from '../abstractions/storage.service';
+import { UserService } from '../abstractions/user.service';
+
+const Keys = {
+    collectionsPrefix: 'collections_',
+};
+
+export class CollectionService {
+    decryptedCollectionCache: any[];
+
+    constructor(private cryptoService: CryptoService, private userService: UserService,
+        private storageService: StorageService) {
+    }
+
+    clearCache(): void {
+        this.decryptedCollectionCache = null;
+    }
+
+    async get(id: string): Promise<Collection> {
+        const userId = await this.userService.getUserId();
+        const collections = await this.storageService.get<{ [id: string]: CollectionData; }>(
+            Keys.collectionsPrefix + userId);
+        if (collections == null || !collections.hasOwnProperty(id)) {
+            return null;
+        }
+
+        return new Collection(collections[id]);
+    }
+
+    async getAll(): Promise<Collection[]> {
+        const userId = await this.userService.getUserId();
+        const collections = await this.storageService.get<{ [id: string]: CollectionData; }>(
+            Keys.collectionsPrefix + userId);
+        const response: Collection[] = [];
+        for (const id in collections) {
+            if (collections.hasOwnProperty(id)) {
+                response.push(new Collection(collections[id]));
+            }
+        }
+        return response;
+    }
+
+    async getAllDecrypted(): Promise<any[]> {
+        if (this.decryptedCollectionCache != null) {
+            return this.decryptedCollectionCache;
+        }
+
+        const key = await this.cryptoService.getKey();
+        if (key == null) {
+            throw new Error('No key.');
+        }
+
+        const decFolders: any[] = [];
+        const promises: Array<Promise<any>> = [];
+        const folders = await this.getAll();
+        folders.forEach((folder) => {
+            promises.push(folder.decrypt().then((f: any) => {
+                decFolders.push(f);
+            }));
+        });
+
+        await Promise.all(promises);
+        this.decryptedCollectionCache = decFolders;
+        return this.decryptedCollectionCache;
+    }
+
+    async upsert(collection: CollectionData | CollectionData[]): Promise<any> {
+        const userId = await this.userService.getUserId();
+        let collections = await this.storageService.get<{ [id: string]: CollectionData; }>(
+            Keys.collectionsPrefix + userId);
+        if (collections == null) {
+            collections = {};
+        }
+
+        if (collection instanceof CollectionData) {
+            const c = collection as CollectionData;
+            collections[c.id] = c;
+        } else {
+            (collection as CollectionData[]).forEach((c) => {
+                collections[c.id] = c;
+            });
+        }
+
+        await this.storageService.save(Keys.collectionsPrefix + userId, collections);
+        this.decryptedCollectionCache = null;
+    }
+
+    async replace(collections: { [id: string]: CollectionData; }): Promise<any> {
+        const userId = await this.userService.getUserId();
+        await this.storageService.save(Keys.collectionsPrefix + userId, collections);
+        this.decryptedCollectionCache = null;
+    }
+
+    async clear(userId: string): Promise<any> {
+        await this.storageService.remove(Keys.collectionsPrefix + userId);
+        this.decryptedCollectionCache = null;
+    }
+
+    async delete(id: string | string[]): Promise<any> {
+        const userId = await this.userService.getUserId();
+        const collections = await this.storageService.get<{ [id: string]: CollectionData; }>(
+            Keys.collectionsPrefix + userId);
+        if (collections == null) {
+            return;
+        }
+
+        if (typeof id === 'string') {
+            const i = id as string;
+            delete collections[id];
+        } else {
+            (id as string[]).forEach((i) => {
+                delete collections[i];
+            });
+        }
+
+        await this.storageService.save(Keys.collectionsPrefix + userId, collections);
+        this.decryptedCollectionCache = null;
+    }
+}
diff --git a/src/services/index.ts b/src/services/index.ts
index 990af9022b..0412506aef 100644
--- a/src/services/index.ts
+++ b/src/services/index.ts
@@ -1,6 +1,7 @@
 export { ApiService } from './api.service';
 export { AppIdService } from './appId.service';
 export { CipherService } from './cipher.service';
+export { CollectionService } from './collection.service';
 export { ConstantsService } from './constants.service';
 export { ContainerService } from './container.service';
 export { CryptoService } from './crypto.service';