diff --git a/CHANGELOG.md b/CHANGELOG.md
index e19dd0f..73a400e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,10 @@
+# [1.21.0](https://github.com/amalv/apollo-server-lambda-postgres/compare/v1.20.0...v1.21.0) (2024-01-04)
+
+
+### Features
+
+* **Book:** add isFavorited to GraphQL schema and resolver ([750f299](https://github.com/amalv/apollo-server-lambda-postgres/commit/750f299386d9eeb16a1b197ddc4e57470c750d96))
+
 # [1.20.0](https://github.com/amalv/apollo-server-lambda-postgres/compare/v1.19.0...v1.20.0) (2024-01-04)
 
 
diff --git a/src/graphql/resolvers/Book.ts b/src/graphql/resolvers/Book.ts
index 3f42573..3804a16 100644
--- a/src/graphql/resolvers/Book.ts
+++ b/src/graphql/resolvers/Book.ts
@@ -1,11 +1,19 @@
 import { dataSource } from "../../data-source";
 import { Book } from "../../entity/Book";
+import { Favorite } from "../../entity/Favorite";
+import { User } from "../../entity/User";
 
 export const BookResolvers = {
   Query: {
     books: async (
       _: any,
-      args: { title?: string; author?: string; cursor?: string; limit?: number }
+      args: {
+        title?: string;
+        author?: string;
+        cursor?: string;
+        limit?: number;
+      },
+      context: { userId?: string }
     ) => {
       try {
         const dataSourceInstance = await dataSource;
@@ -27,6 +35,18 @@ export const BookResolvers = {
             author: `%${args.author.toLowerCase()}%`,
           });
         }
+        let userId;
+
+        if (context.userId) {
+          const user = await dataSourceInstance.getRepository(User).findOne({
+            where: { auth0Id: context.userId },
+          });
+          if (user) {
+            userId = user.id;
+          }
+        }
+
+        queryBuilder.leftJoinAndSelect("book.favorites", "favorite");
 
         books = await queryBuilder
           .orderBy("book.id", "ASC")
@@ -38,7 +58,22 @@ export const BookResolvers = {
 
         return {
           cursor: newCursor,
-          books,
+          books: books.map((book) => {
+            const isFavorited = userId
+              ? book.favorites.some((favorite) => favorite.userId === userId)
+              : false;
+
+            return {
+              id: book.id,
+              title: book.title,
+              author: book.author,
+              publicationDate: book.publicationDate,
+              image: book.image,
+              rating: book.rating,
+              ratingsCount: book.ratingsCount,
+              isFavorited,
+            };
+          }),
         };
       } catch (error) {
         console.error("Error fetching books:", error);
diff --git a/src/graphql/types/Book.ts b/src/graphql/types/Book.ts
index 04d1667..4c3d49c 100644
--- a/src/graphql/types/Book.ts
+++ b/src/graphql/types/Book.ts
@@ -8,5 +8,6 @@ export const BookType = `
     rating: Float!
     ratingsCount: Int!
     favorites: [Favorite!]!
+    isFavorited: Boolean!
   }
 `;