diff --git a/.gitignore b/.gitignore
index 031d3ff..3917fa4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,3 +17,4 @@
 .byebug_history
 .idea/
 public/
+node_modules/
diff --git a/Gemfile b/Gemfile
index 78ccf7b..8045fb4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -31,6 +31,9 @@ gem 'devise_token_auth'
 gem 'cancan'
 gem 'rolify'
 gem 'pry'
+gem 'graphql'
+gem 'graphiql-rails', group: :development
+gem 'batch-loader'
 
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
@@ -48,6 +51,3 @@ group :development do
   gem 'spring'
   gem 'spring-watcher-listen', '~> 2.0.0'
 end
-
-# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
-gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
diff --git a/Gemfile.lock b/Gemfile.lock
index d7503cb..922919d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,50 +1,52 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    actioncable (5.0.2)
-      actionpack (= 5.0.2)
+    actioncable (5.0.6)
+      actionpack (= 5.0.6)
       nio4r (>= 1.2, < 3.0)
       websocket-driver (~> 0.6.1)
-    actionmailer (5.0.2)
-      actionpack (= 5.0.2)
-      actionview (= 5.0.2)
-      activejob (= 5.0.2)
+    actionmailer (5.0.6)
+      actionpack (= 5.0.6)
+      actionview (= 5.0.6)
+      activejob (= 5.0.6)
       mail (~> 2.5, >= 2.5.4)
       rails-dom-testing (~> 2.0)
-    actionpack (5.0.2)
-      actionview (= 5.0.2)
-      activesupport (= 5.0.2)
+    actionpack (5.0.6)
+      actionview (= 5.0.6)
+      activesupport (= 5.0.6)
       rack (~> 2.0)
       rack-test (~> 0.6.3)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (5.0.2)
-      activesupport (= 5.0.2)
+    actionview (5.0.6)
+      activesupport (= 5.0.6)
       builder (~> 3.1)
       erubis (~> 2.7.0)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activejob (5.0.2)
-      activesupport (= 5.0.2)
+    activejob (5.0.6)
+      activesupport (= 5.0.6)
       globalid (>= 0.3.6)
-    activemodel (5.0.2)
-      activesupport (= 5.0.2)
-    activerecord (5.0.2)
-      activemodel (= 5.0.2)
-      activesupport (= 5.0.2)
+    activemodel (5.0.6)
+      activesupport (= 5.0.6)
+    activerecord (5.0.6)
+      activemodel (= 5.0.6)
+      activesupport (= 5.0.6)
       arel (~> 7.0)
-    activesupport (5.0.2)
+    activesupport (5.0.6)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (~> 0.7)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
     arel (7.1.4)
+    batch-loader (1.0.3)
     bcrypt (3.1.11)
     builder (3.2.3)
     byebug (9.0.6)
     cancan (1.6.10)
     coderay (1.1.1)
     concurrent-ruby (1.0.5)
+    crass (1.0.2)
     devise (4.2.0)
       bcrypt (~> 3.0)
       orm_adapter (~> 0.1)
@@ -63,9 +65,12 @@ GEM
     ffi (1.9.18)
     foreman (0.82.0)
       thor (~> 0.19.1)
-    globalid (0.3.7)
-      activesupport (>= 4.1.0)
-    i18n (0.8.1)
+    globalid (0.4.0)
+      activesupport (>= 4.2.0)
+    graphiql-rails (1.4.4)
+      rails
+    graphql (1.7.3)
+    i18n (0.8.6)
     jsonapi-resources (0.9.0)
       activerecord (>= 4.1)
       concurrent-ruby
@@ -73,19 +78,20 @@ GEM
     listen (3.0.8)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    loofah (2.0.3)
+    loofah (2.1.0)
+      crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
-    mail (2.6.4)
+    mail (2.6.6)
       mime-types (>= 1.16, < 4)
     method_source (0.8.2)
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
-    mini_portile2 (2.1.0)
-    minitest (5.10.1)
-    nio4r (2.0.0)
-    nokogiri (1.7.1)
-      mini_portile2 (~> 2.1.0)
+    mini_portile2 (2.3.0)
+    minitest (5.10.3)
+    nio4r (2.1.0)
+    nokogiri (1.8.1)
+      mini_portile2 (~> 2.3.0)
     orm_adapter (0.5.0)
     pg (0.20.0)
     pry (0.10.4)
@@ -93,34 +99,34 @@ GEM
       method_source (~> 0.8.1)
       slop (~> 3.4)
     puma (3.8.2)
-    rack (2.0.1)
+    rack (2.0.3)
     rack-cors (0.4.1)
     rack-test (0.6.3)
       rack (>= 1.0)
-    rails (5.0.2)
-      actioncable (= 5.0.2)
-      actionmailer (= 5.0.2)
-      actionpack (= 5.0.2)
-      actionview (= 5.0.2)
-      activejob (= 5.0.2)
-      activemodel (= 5.0.2)
-      activerecord (= 5.0.2)
-      activesupport (= 5.0.2)
-      bundler (>= 1.3.0, < 2.0)
-      railties (= 5.0.2)
+    rails (5.0.6)
+      actioncable (= 5.0.6)
+      actionmailer (= 5.0.6)
+      actionpack (= 5.0.6)
+      actionview (= 5.0.6)
+      activejob (= 5.0.6)
+      activemodel (= 5.0.6)
+      activerecord (= 5.0.6)
+      activesupport (= 5.0.6)
+      bundler (>= 1.3.0)
+      railties (= 5.0.6)
       sprockets-rails (>= 2.0.0)
-    rails-dom-testing (2.0.2)
-      activesupport (>= 4.2.0, < 6.0)
-      nokogiri (~> 1.6)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
     rails-html-sanitizer (1.0.3)
       loofah (~> 2.0)
-    railties (5.0.2)
-      actionpack (= 5.0.2)
-      activesupport (= 5.0.2)
+    railties (5.0.6)
+      actionpack (= 5.0.6)
+      activesupport (= 5.0.6)
       method_source
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
-    rake (12.0.0)
+    rake (12.1.0)
     rb-fsevent (0.9.8)
     rb-inotify (0.9.8)
       ffi (>= 0.5.0)
@@ -153,7 +159,7 @@ GEM
     sprockets (3.7.1)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.2.0)
+    sprockets-rails (3.2.1)
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)
@@ -171,12 +177,15 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  batch-loader
   byebug
   cancan
   devise_token_auth
   factory_girl
   faker
   foreman
+  graphiql-rails
+  graphql
   jsonapi-resources
   listen (~> 3.0.5)
   pg (~> 0.18)
@@ -188,7 +197,6 @@ DEPENDENCIES
   rspec-rails
   spring
   spring-watcher-listen (~> 2.0.0)
-  tzinfo-data
 
 BUNDLED WITH
    1.14.6
diff --git a/README.md b/README.md
index be56415..3ec5282 100644
--- a/README.md
+++ b/README.md
@@ -28,3 +28,140 @@ Demo user: user1@example.com / Secret123
 ### Client
 
 Add list, edit and form components in `client/src/components/` based on one of existing.
+
+### [graphiql](http://localhost:3001/graphiql)
+
+Categories
+
+     {
+       categories {
+         id
+         name
+       }
+     }
+
+Categories with posts
+
+    {
+      categories(with_posts: true) {
+        id
+        name
+        posts {
+          id
+          title
+          category {
+            id
+            name
+          }
+          comments {
+            id
+            body
+          }
+        }
+      }
+    }
+
+One category
+    
+    {
+      category(id: 1) {
+        id
+        name
+      }
+    }
+
+Create category
+
+    mutation {
+      createCategory(category: {name: "Graphql"}) {
+        id
+        name
+        errors
+      }
+    }
+
+Update category
+
+    mutation {
+      updateCategory(category: {id: 1, name: "Graphql"}) {
+        id
+        name
+        errors
+      }
+    }
+
+Delete category
+
+    mutation {
+      deleteCategory(id: 24) {
+        id
+        name
+      }
+    }
+
+Posts
+
+    {
+      posts {
+        id
+        title
+        category {
+          id
+          name
+        }
+      }
+    }
+
+One post
+
+    {
+      post(id: 1) {
+        id
+        title
+        category {
+          id
+          name
+        }
+        comments {
+          id
+          body
+        }
+      }
+    }
+
+Create post
+
+    mutation {
+      createPost(post: {title: "Graphql", category_id: 1}) {
+        id
+        title
+        category {
+          id
+          name
+        }
+        errors
+      }
+    }
+
+Update post
+
+    mutation {
+      updatePost(post: {id: 1, title: "Graphql", category_id: 1}) {
+        id
+        title
+        category {
+          id
+          name
+        }
+        errors
+      }
+    }
+
+Delete post
+
+    mutation {
+      deletePost(id: 83) {
+        id
+        title
+      }
+    }
diff --git a/app/controllers/graphql_controller.rb b/app/controllers/graphql_controller.rb
new file mode 100644
index 0000000..4194008
--- /dev/null
+++ b/app/controllers/graphql_controller.rb
@@ -0,0 +1,32 @@
+class GraphqlController < ApplicationController
+  def execute
+    variables = ensure_hash(params[:variables])
+    query = params[:query]
+    context = {
+      # Query context goes here, for example:
+      # current_user: current_user,
+    }
+    result = RailsJsonApiServerSchema.execute(query, variables: variables, context: context)
+    render json: result
+  end
+
+  private
+
+  # Handle form data, JSON body, or a blank value
+  def ensure_hash(ambiguous_param)
+    case ambiguous_param
+    when String
+      if ambiguous_param.present?
+        ensure_hash(JSON.parse(ambiguous_param))
+      else
+        {}
+      end
+    when Hash, ActionController::Parameters
+      ambiguous_param
+    when nil
+      {}
+    else
+      raise ArgumentError, "Unexpected parameter: #{ambiguous_param}"
+    end
+  end
+end
diff --git a/app/graphql/mutations/.keep b/app/graphql/mutations/.keep
new file mode 100644
index 0000000..e69de29
diff --git a/app/graphql/rails_json_api_server_schema.rb b/app/graphql/rails_json_api_server_schema.rb
new file mode 100644
index 0000000..e86927d
--- /dev/null
+++ b/app/graphql/rails_json_api_server_schema.rb
@@ -0,0 +1,7 @@
+RailsJsonApiServerSchema = GraphQL::Schema.define do
+  query Types::QueryType
+  mutation Types::MutationType
+  use BatchLoader::GraphQL
+  max_depth 10
+  rescue_from(ActiveRecord::RecordNotFound) { "Not found" }
+end
diff --git a/app/graphql/types/.keep b/app/graphql/types/.keep
new file mode 100644
index 0000000..e69de29
diff --git a/app/graphql/types/category_type.rb b/app/graphql/types/category_type.rb
new file mode 100644
index 0000000..a230f36
--- /dev/null
+++ b/app/graphql/types/category_type.rb
@@ -0,0 +1,16 @@
+Types::CategoryType = GraphQL::ObjectType.define do
+  name "Category"
+
+  field :id, types.Int
+  field :name, types.String
+  field :created_at, types.String
+  field :posts, types[Types::PostType]
+  field :errors, Types::JSONType
+end
+
+Types::CategoryInputType = GraphQL::InputObjectType.define do
+  name "CategoryInput"
+
+  argument :id, types.Int
+  argument :name, types.String
+end
diff --git a/app/graphql/types/comment_type.rb b/app/graphql/types/comment_type.rb
new file mode 100644
index 0000000..b2d6235
--- /dev/null
+++ b/app/graphql/types/comment_type.rb
@@ -0,0 +1,8 @@
+Types::CommentType = GraphQL::ObjectType.define do
+  name "Comment"
+
+  field :id, types.Int
+  field :body, types.String
+  field :created_at, types.String
+  field :post, Types::PostType
+end
diff --git a/app/graphql/types/json_type.rb b/app/graphql/types/json_type.rb
new file mode 100644
index 0000000..08140ca
--- /dev/null
+++ b/app/graphql/types/json_type.rb
@@ -0,0 +1,6 @@
+Types::JSONType = GraphQL::ScalarType.define do
+  name "JSON"
+
+  # coerce_input ->(value, _ctx) { value }
+  # coerce_result ->(value, _ctx) { value }
+end
diff --git a/app/graphql/types/mutation_type.rb b/app/graphql/types/mutation_type.rb
new file mode 100644
index 0000000..2c251b1
--- /dev/null
+++ b/app/graphql/types/mutation_type.rb
@@ -0,0 +1,52 @@
+Types::MutationType = GraphQL::ObjectType.define do
+  name "Mutation"
+
+  field :createCategory, Types::CategoryType do
+    description "Create a category"
+    argument :category, Types::CategoryInputType
+    resolve ->(o, args, c) {
+      Category.create(args[:category].to_h)
+    }
+  end
+
+  field :updateCategory, Types::CategoryType do
+    description "Update a category"
+    argument :category, Types::CategoryInputType
+    resolve ->(o, args, c) {
+      Category.update(args[:category][:id], args[:category].to_h.except!("id"))
+    }
+  end
+
+  field :deleteCategory, Types::CategoryType do
+    description "Delete a category"
+    argument :id, types.Int
+    resolve ->(o, args, c) {
+      Category.destroy(args[:id])
+    }
+  end
+
+  field :createPost, Types::PostType do
+    description "Create a post"
+
+    argument :post, Types::PostInputType
+    resolve ->(o, args, c) {
+      Post.create(args[:post].to_h)
+    }
+  end
+
+  field :updatePost, Types::PostType do
+    description "Update a post"
+    argument :post, Types::PostInputType
+    resolve ->(o, args, c) {
+      Post.update(args[:post][:id], args[:post].to_h.except!("id"))
+    }
+  end
+
+  field :deletePost, Types::PostType do
+    description "Delete a post"
+    argument :id, types.Int
+    resolve ->(o, args, c) {
+      Post.destroy(args[:id])
+    }
+  end
+end
diff --git a/app/graphql/types/post_type.rb b/app/graphql/types/post_type.rb
new file mode 100644
index 0000000..f132a31
--- /dev/null
+++ b/app/graphql/types/post_type.rb
@@ -0,0 +1,25 @@
+Types::PostType = GraphQL::ObjectType.define do
+  name "Post"
+
+  field :id, types.Int
+  field :title, types.String
+  field :created_at, types.String
+  field :category do
+    type Types::CategoryType
+    resolve ->(obj, args, ctx) {
+      BatchLoader.for(obj.category_id).batch do |ids, loader|
+        Category.where(id: ids).each { |record| loader.call(record.id, record) }
+      end
+    }
+  end
+  field :comments, types[Types::CommentType]
+  field :errors, Types::JSONType
+end
+
+Types::PostInputType = GraphQL::InputObjectType.define do
+  name "PostInput"
+
+  argument :id, types.Int
+  argument :title, types.String
+  argument :category_id, types.Int
+end
diff --git a/app/graphql/types/query_type.rb b/app/graphql/types/query_type.rb
new file mode 100644
index 0000000..4db6ff0
--- /dev/null
+++ b/app/graphql/types/query_type.rb
@@ -0,0 +1,38 @@
+Types::QueryType = GraphQL::ObjectType.define do
+  name "Query"
+  description "The query root of this schema"
+
+  field :category do
+    type Types::CategoryType
+    argument :id, !types.ID
+    description "Find a Category by ID"
+    resolve ->(obj, args, ctx) { Category.find(args["id"]) }
+  end
+
+  field :categories do
+    type types[Types::CategoryType]
+    argument :id, types[types.ID]
+    argument :with_posts, types.Boolean
+    description "Find Categories"
+    resolve ->(obj, args, ctx) {
+      categories = (args["ids"] ? Category.where(id: args["ids"]) : Category.all)
+      args["with_posts"] ? categories.includes(posts: :comments) : categories
+    }
+  end
+
+  field :posts do
+    type types[Types::PostType]
+    argument :id, types[types.ID]
+    description "Find Posts"
+    resolve ->(obj, args, ctx) {
+      args["ids"] ? Post.where(id: args["ids"]) : Post.all
+    }
+  end
+
+  field :post do
+    type Types::PostType
+    argument :id, !types.ID
+    description "Find a Post by ID"
+    resolve ->(obj, args, ctx) { Post.find(args["id"]) }
+  end
+end
diff --git a/config/application.rb b/config/application.rb
index 56c997b..cd2af55 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -9,7 +9,7 @@
 require "action_mailer/railtie"
 require "action_view/railtie"
 require "action_cable/engine"
-# require "sprockets/railtie"
+require "sprockets/railtie"
 require "rails/test_unit/railtie"
 
 # Require the gems listed in Gemfile, including any gems
@@ -38,5 +38,7 @@ class Application < Rails::Application
     # This is necessary if your schema can't be completely dumped by the schema dumper,
     # like if you have constraints or database-specific column types
     config.active_record.schema_format = :sql
+
+    config.autoload_paths << Rails.root.join("app", "types")
   end
 end
diff --git a/config/routes.rb b/config/routes.rb
index bd0a65d..2fe9636 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,4 +1,9 @@
 Rails.application.routes.draw do
+  if Rails.env.development?
+    mount GraphiQL::Rails::Engine, at: "/graphiql", graphql_path: "/graphql"
+  end
+
+  post "/graphql", to: "graphql#execute"
   mount_devise_token_auth_for 'User', at: 'auth'
   jsonapi_resources :categories
   jsonapi_resources :comments