diff --git a/src/api/authorization/index.ts b/src/api/authorization/index.ts
deleted file mode 100644
index 063b3e42..00000000
--- a/src/api/authorization/index.ts
+++ /dev/null
@@ -1,35 +0,0 @@
-import { shield, and } from 'graphql-shield';
-
-import { isAuthenticated } from './isAuthenticated';
-import { isAdmin } from './isAdmin';
-import { isPartner } from './isPartner';
-import { isFreeCourse } from './isFreeCourse';
-
-export default shield({
-  Query: {
-    // me: isAuthenticated,
-    // discountedPrice: isAuthenticated,
-
-    // Partner
-
-    partnerVisitors: and(isAuthenticated, isPartner),
-    partnerSales: and(isAuthenticated, isPartner),
-    partnerPayments: and(isAuthenticated, isPartner),
-  },
-  Mutation: {
-    // passwordChange: isAuthenticated,
-    // emailChange: isAuthenticated,
-    communityJoin: isAuthenticated,
-
-    // Admin
-
-    migrate: and(isAuthenticated, isAdmin),
-    promoteToPartner: and(isAuthenticated, isAdmin),
-    couponCreate: and(isAuthenticated, isAdmin),
-    createAdminCourse: and(isAuthenticated, isAdmin),
-
-    // Free
-
-    createFreeCourse: and(isAuthenticated, isFreeCourse),
-  },
-});
diff --git a/src/api/authorization/isAdmin.ts b/src/api/authorization/isAdmin.ts
deleted file mode 100644
index 86c3bb2f..00000000
--- a/src/api/authorization/isAdmin.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-import { rule } from 'graphql-shield';
-import { ForbiddenError } from 'apollo-server';
-
-import { hasAdminRole } from '@validation/admin';
-
-export const isAdmin = rule()(async (_, __, { me }) => {
-  if (!me) {
-    return new ForbiddenError('Not authenticated as user.');
-  }
-
-  return hasAdminRole(me)
-    ? true
-    : new ForbiddenError('No admin user.');
-});
diff --git a/src/api/authorization/isAuthenticated.ts b/src/api/authorization/isAuthenticated.ts
deleted file mode 100644
index 038a336e..00000000
--- a/src/api/authorization/isAuthenticated.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-import { rule } from 'graphql-shield';
-import { ForbiddenError } from 'apollo-server';
-
-export const isAuthenticated = rule()(async (_, __, { me }) => {
-  return me ? true : new ForbiddenError('Not authenticated as user.');
-});
diff --git a/src/api/authorization/isFreeCourse.ts b/src/api/authorization/isFreeCourse.ts
deleted file mode 100644
index 6944e98a..00000000
--- a/src/api/authorization/isFreeCourse.ts
+++ /dev/null
@@ -1,19 +0,0 @@
-import { rule } from 'graphql-shield';
-
-import storefront from '@data/course-storefront';
-import { COURSE } from '@data/course-keys-types';
-import { BUNDLE } from '@data/bundle-keys-types';
-
-export const isFreeCourse = rule()(
-  async (
-    _,
-    { courseId, bundleId }: { courseId: COURSE; bundleId: BUNDLE }
-  ) => {
-    const course = storefront[courseId];
-    const bundle = course.bundles[bundleId];
-
-    return bundle.price === 0
-      ? true
-      : new Error('This course is not for free.');
-  }
-);
diff --git a/src/api/authorization/isPartner.ts b/src/api/authorization/isPartner.ts
deleted file mode 100644
index 787ee7e2..00000000
--- a/src/api/authorization/isPartner.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-import { rule } from 'graphql-shield';
-import { ForbiddenError } from 'apollo-server';
-
-import { hasPartnerRole } from '@validation/partner';
-
-export const isPartner = rule()(async (_, __, { me }) => {
-  if (!me) {
-    return new ForbiddenError('Not authenticated as user.');
-  }
-
-  return hasPartnerRole(me)
-    ? true
-    : new ForbiddenError('No partner user.');
-});
diff --git a/src/api/middleware/resolver/isFreeCourse.ts b/src/api/middleware/resolver/isFreeCourse.ts
new file mode 100644
index 00000000..1a1fdb2a
--- /dev/null
+++ b/src/api/middleware/resolver/isFreeCourse.ts
@@ -0,0 +1,20 @@
+import { MiddlewareFn } from 'type-graphql';
+
+import { ResolverContext } from '@typeDefs/resolver';
+import storefront from '@data/course-storefront';
+import { COURSE } from '@data/course-keys-types';
+import { BUNDLE } from '@data/bundle-keys-types';
+
+export const isFreeCourse: MiddlewareFn<ResolverContext> = async (
+  { args },
+  next
+) => {
+  const course = storefront[args.courseId as COURSE];
+  const bundle = course.bundles[args.bundleId as BUNDLE];
+
+  if (bundle.price !== 0) {
+    throw new Error('This course is not for free.');
+  }
+
+  return next();
+};
diff --git a/src/api/middleware/resolver/isPartner.ts b/src/api/middleware/resolver/isPartner.ts
new file mode 100644
index 00000000..dcfbe3a7
--- /dev/null
+++ b/src/api/middleware/resolver/isPartner.ts
@@ -0,0 +1,20 @@
+import { MiddlewareFn } from 'type-graphql';
+import { ForbiddenError } from 'apollo-server';
+
+import { ResolverContext } from '@typeDefs/resolver';
+import { hasPartnerRole } from '@validation/partner';
+
+export const isPartner: MiddlewareFn<ResolverContext> = async (
+  { context },
+  next
+) => {
+  if (!context.me) {
+    throw new ForbiddenError('Not authenticated as user.');
+  }
+
+  if (!hasPartnerRole(context.me)) {
+    throw new Error('No partner user.');
+  }
+
+  return next();
+};
diff --git a/src/api/resolvers/book/index.ts b/src/api/resolvers/book/index.ts
index 5b4d625b..66dbf777 100644
--- a/src/api/resolvers/book/index.ts
+++ b/src/api/resolvers/book/index.ts
@@ -6,7 +6,9 @@ import {
   Arg,
   Resolver,
   Query,
+  UseMiddleware,
 } from 'type-graphql';
+import { isAuthenticated } from '@api/middleware/resolver/isAuthenticated';
 
 @ObjectType()
 class File {
@@ -29,35 +31,45 @@ class Markdown {
 @Resolver()
 export default class BookResolver {
   @Query(() => File)
+  @UseMiddleware(isAuthenticated)
   async book(
     @Arg('path') path: string,
     @Arg('fileName') fileName: string
-  ) {
-    const data = await s3
+  ): Promise<File> {
+    const { ContentType, Body } = await s3
       .getObject({
         Bucket: bucket,
         Key: path,
       })
       .promise();
 
+    if (!ContentType || !Body) {
+      throw new Error("Book couldn't get downloaded.");
+    }
+
     return {
       fileName,
-      contentType: data.ContentType,
-      body: data?.Body?.toString('base64'),
+      contentType: ContentType,
+      body: Body.toString('base64'),
     };
   }
 
   @Query(() => Markdown)
-  async onlineChapter(@Arg('path') path: string) {
-    const data = await s3
+  @UseMiddleware(isAuthenticated)
+  async onlineChapter(@Arg('path') path: string): Promise<Markdown> {
+    const { Body } = await s3
       .getObject({
         Bucket: bucket,
         Key: path,
       })
       .promise();
 
+    if (!Body) {
+      throw new Error("Chapter couldn't get downloaded.");
+    }
+
     return {
-      body: data?.Body?.toString('base64'),
+      body: Body.toString('base64'),
     };
   }
 }
diff --git a/src/api/resolvers/community/index.ts b/src/api/resolvers/community/index.ts
index 80925efc..91e31521 100644
--- a/src/api/resolvers/community/index.ts
+++ b/src/api/resolvers/community/index.ts
@@ -1,6 +1,7 @@
-import { Arg, Resolver, Mutation } from 'type-graphql';
+import { Arg, Resolver, Mutation, UseMiddleware } from 'type-graphql';
 
 import { inviteToSlack } from '@services/slack';
+import { isAuthenticated } from '@api/middleware/resolver/isAuthenticated';
 
 // https://api.slack.com/methods/admin.users.invite
 const SLACK_ERRORS: { [key: string]: string } = {
@@ -61,19 +62,20 @@ const SLACK_ERRORS: { [key: string]: string } = {
 @Resolver()
 export default class CommunityResolver {
   @Mutation(() => Boolean)
-  async communityJoin(@Arg('email') email: string) {
+  @UseMiddleware(isAuthenticated)
+  async communityJoin(@Arg('email') email: string): Promise<Boolean> {
     try {
       const result = await inviteToSlack(email);
 
       if (!result) {
-        return new Error('Something went wrong.');
+        throw new Error('Something went wrong.');
       }
 
       if (!result.data.ok) {
-        return new Error(SLACK_ERRORS[result.data.error]);
+        throw new Error(SLACK_ERRORS[result.data.error]);
       }
     } catch (error) {
-      return new Error(error);
+      throw new Error(error);
     }
 
     return true;
diff --git a/src/api/resolvers/course/index.ts b/src/api/resolvers/course/index.ts
index 2d4e6a09..c53a294b 100644
--- a/src/api/resolvers/course/index.ts
+++ b/src/api/resolvers/course/index.ts
@@ -6,6 +6,7 @@ import {
   Resolver,
   Query,
   Mutation,
+  UseMiddleware,
 } from 'type-graphql';
 
 import { StorefrontCourse } from '@api/resolvers/storefront';
@@ -14,6 +15,9 @@ import { createCourse } from '@services/firebase/course';
 import { mergeCourses } from '@services/course';
 import { COURSE } from '@data/course-keys-types';
 import { BUNDLE } from '@data/bundle-keys-types';
+import { isAuthenticated } from '@api/middleware/resolver/isAuthenticated';
+import { isFreeCourse } from '@api/middleware/resolver/isFreeCourse';
+import { isAdmin } from '@api/middleware/resolver/isAdmin';
 
 @ObjectType()
 class CurriculumItem {
@@ -229,17 +233,14 @@ export default class CourseResolver {
     }));
   }
 
-  @Query(() => UnlockedCourse, { nullable: true })
+  @Query(() => UnlockedCourse)
+  @UseMiddleware(isAuthenticated)
   async unlockedCourse(
     @Arg('courseId') courseId: string,
     @Ctx() ctx: ResolverContext
-  ): Promise<UnlockedCourse | null> {
-    if (!ctx.me) {
-      return null;
-    }
-
+  ): Promise<UnlockedCourse> {
     const courses = await ctx.courseConnector.getCoursesByUserIdAndCourseId(
-      ctx.me.uid,
+      ctx.me!.uid,
       courseId as COURSE
     );
 
@@ -253,6 +254,7 @@ export default class CourseResolver {
   }
 
   @Mutation(() => Boolean)
+  @UseMiddleware(isAuthenticated, isFreeCourse)
   async createFreeCourse(
     @Arg('courseId') courseId: string,
     @Arg('bundleId') bundleId: string,
@@ -287,6 +289,7 @@ export default class CourseResolver {
   }
 
   @Mutation(() => Boolean)
+  @UseMiddleware(isAuthenticated, isAdmin)
   async createAdminCourse(
     @Arg('courseId') courseId: string,
     @Arg('bundleId') bundleId: string,
diff --git a/src/api/resolvers/migration/index.ts b/src/api/resolvers/migration/index.ts
index 5d57bfcf..c1e1d4c1 100644
--- a/src/api/resolvers/migration/index.ts
+++ b/src/api/resolvers/migration/index.ts
@@ -1,9 +1,14 @@
-import { Arg, Resolver, Mutation } from 'type-graphql';
+import { Arg, Resolver, Mutation, UseMiddleware } from 'type-graphql';
+import { isAuthenticated } from '@api/middleware/resolver/isAuthenticated';
+import { isAdmin } from '@api/middleware/resolver/isAdmin';
 
 @Resolver()
 export default class MigrationResolver {
   @Mutation(() => Boolean)
-  async migrate(@Arg('migrationType') migrationType: string) {
+  @UseMiddleware(isAuthenticated, isAdmin)
+  async migrate(
+    @Arg('migrationType') migrationType: string
+  ): Promise<Boolean> {
     switch (migrationType) {
       case 'FOO':
         return true;
diff --git a/src/api/resolvers/partner/index.ts b/src/api/resolvers/partner/index.ts
index eb4f7b41..e6902dd7 100644
--- a/src/api/resolvers/partner/index.ts
+++ b/src/api/resolvers/partner/index.ts
@@ -6,10 +6,14 @@ import {
   Resolver,
   Query,
   Mutation,
+  UseMiddleware,
 } from 'type-graphql';
 
 import { ResolverContext } from '@typeDefs/resolver';
 import { hasPartnerRole } from '@validation/partner';
+import { isAuthenticated } from '@api/middleware/resolver/isAuthenticated';
+import { isAdmin } from '@api/middleware/resolver/isAdmin';
+import { isPartner } from '@api/middleware/resolver/isPartner';
 
 @ObjectType()
 export class VisitorByDay {
@@ -70,11 +74,12 @@ export class PartnerPayment {
 @Resolver()
 export default class PartnerResolver {
   @Query(() => [VisitorByDay])
+  @UseMiddleware(isAuthenticated, isPartner)
   async partnerVisitors(
     @Arg('from') from: Date,
     @Arg('to') to: Date,
     @Ctx() ctx: ResolverContext
-  ) {
+  ): Promise<VisitorByDay[]> {
     try {
       return await ctx.partnerConnector.getVisitorsBetweenAggregatedByDate(
         from,
@@ -86,21 +91,18 @@ export default class PartnerResolver {
   }
 
   @Query(() => PartnerSaleConnection)
+  @UseMiddleware(isAuthenticated, isPartner)
   async partnerSales(
     @Arg('offset') offset: number,
     @Arg('limit') limit: number,
     @Ctx() ctx: ResolverContext
-  ) {
-    if (!ctx.me) {
-      return [];
-    }
-
+  ): Promise<PartnerSaleConnection> {
     try {
       const {
         edges,
         total,
       } = await ctx.partnerConnector.getSalesByPartner(
-        ctx.me.uid,
+        ctx.me!.uid,
         offset,
         limit
       );
@@ -120,19 +122,18 @@ export default class PartnerResolver {
         },
       };
     } catch (error) {
-      return [];
+      throw new Error(error);
     }
   }
 
   @Query(() => [PartnerPayment])
-  async partnerPayments(@Ctx() ctx: ResolverContext) {
-    if (!ctx.me) {
-      return [];
-    }
-
+  @UseMiddleware(isAuthenticated, isPartner)
+  async partnerPayments(
+    @Ctx() ctx: ResolverContext
+  ): Promise<PartnerPayment[]> {
     try {
       return await ctx.partnerConnector.getPaymentsByPartner(
-        ctx.me.uid
+        ctx.me!.uid
       );
     } catch (error) {
       return [];
@@ -140,10 +141,11 @@ export default class PartnerResolver {
   }
 
   @Mutation(() => Boolean)
+  @UseMiddleware(isAuthenticated, isAdmin)
   async promoteToPartner(
     @Arg('uid') uid: string,
     @Ctx() ctx: ResolverContext
-  ) {
+  ): Promise<Boolean> {
     try {
       await ctx.adminConnector.setCustomClaims(uid, {
         partner: true,
@@ -159,7 +161,7 @@ export default class PartnerResolver {
   async partnerTrackVisitor(
     @Arg('partnerId') partnerId: string,
     @Ctx() ctx: ResolverContext
-  ) {
+  ): Promise<Boolean> {
     try {
       const partner = await ctx.adminConnector.getUser(partnerId);
 
diff --git a/src/api/resolvers/storefront/index.ts b/src/api/resolvers/storefront/index.ts
index c1fceb4b..fdc04272 100644
--- a/src/api/resolvers/storefront/index.ts
+++ b/src/api/resolvers/storefront/index.ts
@@ -49,7 +49,7 @@ export class StorefrontCourse {
   canUpgrade: boolean;
 
   @Field()
-  bundle: StorefrontBundle;
+  bundle?: StorefrontBundle;
 }
 
 @Resolver()
@@ -58,7 +58,7 @@ export default class StorefrontResolver {
   async storefrontCourse(
     @Arg('courseId') courseId: string,
     @Arg('bundleId') bundleId: string
-  ) {
+  ): Promise<StorefrontCourse> {
     const course = storefront[courseId as COURSE];
     const bundle = course.bundles[bundleId as BUNDLE];
 
@@ -74,7 +74,7 @@ export default class StorefrontResolver {
   }
 
   @Query(() => [StorefrontCourse])
-  async storefrontCourses() {
+  async storefrontCourses(): Promise<StorefrontCourse[]> {
     return Object.values(storefront).map(storefrontCourse => ({
       courseId: storefrontCourse.courseId,
       header: storefrontCourse.header,
@@ -85,7 +85,9 @@ export default class StorefrontResolver {
   }
 
   @Query(() => [StorefrontBundle])
-  async storefrontBundles(@Arg('courseId') courseId: string) {
+  async storefrontBundles(
+    @Arg('courseId') courseId: string
+  ): Promise<StorefrontBundle[]> {
     const course = storefront[courseId as COURSE];
 
     return sortBy(
diff --git a/src/api/resolvers/stripe/index.ts b/src/api/resolvers/stripe/index.ts
index b6978b02..beb5f3d1 100644
--- a/src/api/resolvers/stripe/index.ts
+++ b/src/api/resolvers/stripe/index.ts
@@ -5,6 +5,7 @@ import {
   Ctx,
   Resolver,
   Mutation,
+  UseMiddleware,
 } from 'type-graphql';
 
 import { COURSE } from '@data/course-keys-types';
@@ -21,6 +22,7 @@ import { priceWithDiscount } from '@services/discount';
 import stripe from '@services/stripe';
 
 import storefront from '@data/course-storefront';
+import { isAuthenticated } from '@api/middleware/resolver/isAuthenticated';
 
 // https://stripe.com/docs/payments/checkout/one-time#create-one-time-payments
 @Resolver()
diff --git a/src/api/resolvers/upgrade/index.ts b/src/api/resolvers/upgrade/index.ts
index 5c4e51d8..80f23375 100644
--- a/src/api/resolvers/upgrade/index.ts
+++ b/src/api/resolvers/upgrade/index.ts
@@ -1,23 +1,27 @@
-import { Arg, Ctx, Resolver, Query } from 'type-graphql';
+import {
+  Arg,
+  Ctx,
+  Resolver,
+  Query,
+  UseMiddleware,
+} from 'type-graphql';
 
 import { StorefrontCourse } from '@api/resolvers/storefront';
 import { ResolverContext } from '@typeDefs/resolver';
 import { getUpgradeableCourses } from '@services/course';
 import { COURSE } from '@data/course-keys-types';
+import { isAuthenticated } from '@api/middleware/resolver/isAuthenticated';
 
 @Resolver()
 export default class UpgradeResolver {
   @Query(() => [StorefrontCourse])
+  @UseMiddleware(isAuthenticated)
   async upgradeableCourses(
     @Arg('courseId') courseId: string,
     @Ctx() ctx: ResolverContext
   ) {
-    if (!ctx.me) {
-      return [];
-    }
-
     const courses = await ctx.courseConnector.getCoursesByUserIdAndCourseId(
-      ctx.me.uid,
+      ctx.me!.uid,
       courseId as COURSE
     );
 
diff --git a/src/generated/client.tsx b/src/generated/client.tsx
index 6347986e..a88b08e9 100644
--- a/src/generated/client.tsx
+++ b/src/generated/client.tsx
@@ -129,7 +129,7 @@ export type Mutation = {
   stripeCreateOrder: StripeId;
   createFreeCourse: Scalars['Boolean'];
   createAdminCourse: Scalars['Boolean'];
-  couponCreate?: Maybe<Scalars['Boolean']>;
+  couponCreate: Scalars['Boolean'];
   promoteToPartner: Scalars['Boolean'];
   partnerTrackVisitor: Scalars['Boolean'];
   communityJoin: Scalars['Boolean'];
@@ -284,7 +284,7 @@ export type Query = {
   storefrontCourses: Array<StorefrontCourse>;
   storefrontBundles: Array<StorefrontBundle>;
   unlockedCourses: Array<StorefrontCourse>;
-  unlockedCourse?: Maybe<UnlockedCourse>;
+  unlockedCourse: UnlockedCourse;
   book: File;
   onlineChapter: Markdown;
   upgradeableCourses: Array<StorefrontCourse>;
@@ -391,8 +391,8 @@ export type UnlockedCourse = {
 
 export type User = {
    __typename?: 'User';
-  email: Scalars['String'];
   uid: Scalars['String'];
+  email: Scalars['String'];
   username: Scalars['String'];
   roles: Array<Scalars['String']>;
 };
@@ -485,7 +485,7 @@ export type GetCourseQueryVariables = {
 
 export type GetCourseQuery = (
   { __typename?: 'Query' }
-  & { unlockedCourse?: Maybe<(
+  & { unlockedCourse: (
     { __typename?: 'UnlockedCourse' }
     & Pick<UnlockedCourse, 'courseId' | 'header' | 'canUpgrade'>
     & { introduction?: Maybe<(
@@ -544,7 +544,7 @@ export type GetCourseQuery = (
         )> }
       )> }
     )> }
-  )> }
+  ) }
 );
 
 export type CreateFreeCourseMutationVariables = {