diff --git a/.gitignore b/.gitignore
index a36ad2e..3c230d8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,6 +31,6 @@
 
 /public/assets
 /.idea
-/test
+/db/schema.rb
 # Ignore master key for decrypting credentials and more.
 /config/master.key
diff --git a/app/controllers/api/assemblies_controller.rb b/app/controllers/api/assemblies_controller.rb
new file mode 100644
index 0000000..e1834c0
--- /dev/null
+++ b/app/controllers/api/assemblies_controller.rb
@@ -0,0 +1,47 @@
+module Api
+  class AssembliesController < ApplicationController
+    skip_before_action :verify_authenticity_token
+    before_action :set_assembly, only: %i[show update destroy]
+    def index
+      @assemblies = Assembly.all
+      render json: @assemblies, except: %i[created_at]
+    end
+
+    def show
+      render json: @assembly
+    end
+
+    def create
+      @assembly = Assembly.new(params_assembly)
+
+      if @assembly.save
+        render json: @assembly, status: :created, except: %i[created_at]
+      else
+        render json: @assembly.errors.full_messages, status: :unprocessable_entity
+      end
+    end
+
+    def update
+      if @assembly.update(params_assembly)
+        render json: @assembly, except: %i[created_at]
+      else
+        render json: @assembly.errors.full_messages, status: :unprocessable_entity
+      end
+    end
+
+    def destroy
+      @assembly.destroy
+      head :no_content
+    end
+
+    private
+
+    def set_assembly
+      @assembly = Assembly.find(params[:id])
+    end
+
+    def params_assembly
+      params.require(:assembly).permit(:name, part_ids: [], book_ids: [])
+    end
+  end
+end
diff --git a/app/controllers/assemblies_controller.rb b/app/controllers/assemblies_controller.rb
index 53ca4b0..068a920 100644
--- a/app/controllers/assemblies_controller.rb
+++ b/app/controllers/assemblies_controller.rb
@@ -1,78 +1,58 @@
 class AssembliesController < ApplicationController
-  before_action :set_assembly, only: %i[ show edit update destroy ]
-  before_action :set_part_id_options, only: %i[ new show edit update destroy ]
-  before_action :set_book_id_options, only: %i[ new show edit update destroy ]
+  before_action :set_assembly, only: %i[show edit update destroy]
+  before_action :set_part_id_options, only: %i[new show edit update destroy]
+  before_action :set_book_id_options, only: %i[new show edit update destroy]
 
-  # GET /assemblies or /assemblies.json
   def index
     @assemblies = Assembly.all
   end
 
-  # GET /assemblies/1 or /assemblies/1.json
-  def show
-  end
+  def show; end
 
-  # GET /assemblies/new
   def new
     @assembly = Assembly.new
   end
 
-  # GET /assemblies/1/edit
-  def edit
-  end
+  def edit; end
 
-  # POST /assemblies or /assemblies.json
   def create
     @assembly = Assembly.new(assembly_params)
-
-    respond_to do |format|
-      if @assembly.save
-        format.html { redirect_to assembly_url(@assembly), notice: "Assembly was successfully created." }
-        format.json { render :show, status: :created, location: @assembly }
-      else
-        format.html { render :new, status: :unprocessable_entity }
-        format.json { render json: @assembly.errors, status: :unprocessable_entity }
-      end
+    if @assembly.save
+      redirect_to assembly_url(@assembly), notice: 'Assembly was successfully created.'
+    else
+      render :new, status: :unprocessable_entity
     end
   end
 
-  # PATCH/PUT /assemblies/1 or /assemblies/1.json
   def update
-    respond_to do |format|
-      if @assembly.update(assembly_params)
-        format.html { redirect_to assembly_url(@assembly), notice: "Assembly was successfully updated." }
-        format.json { render :show, status: :ok, location: @assembly }
-      else
-        format.html { render :edit, status: :unprocessable_entity }
-        format.json { render json: @assembly.errors, status: :unprocessable_entity }
-      end
+    if @assembly.update(assembly_params)
+      redirect_to assembly_url(@assembly), notice: 'Assembly was successfully updated.'
+    else
+      render :edit, status: :unprocessable_entity
     end
   end
 
-  # DELETE /assemblies/1 or /assemblies/1.json
   def destroy
     @assembly.destroy
-
-    respond_to do |format|
-      format.html { redirect_to assemblies_url, notice: "Assembly was successfully destroyed." }
-      format.json { head :no_content }
-    end
+    redirect_to assemblies_url, notice: 'Assembly was successfully destroyed.'
   end
 
   private
-    # Use callbacks to share common setup or constraints between actions.
-    def set_book_id_options
-      @book_id_options = Book.all.pluck(:published_at, :id)
-    end
-    def set_part_id_options
-      @part_id_options = Part.all.pluck(:part_number, :id)
-    end
-    def set_assembly
-      @assembly = Assembly.find(params[:id])
-    end
 
-    # Only allow a list of trusted parameters through.
-    def assembly_params
-      params.require(:assembly).permit(:name, :part_id, :book_id)
-    end
+  def set_book_id_options
+    @book_id_options = Book.all.pluck(:published_at, :id)
+  end
+
+  def set_part_id_options
+    @part_id_options = Part.all.pluck(:part_number, :id)
+  end
+
+  def set_assembly
+    @assembly = Assembly.find(params[:id])
+  end
+
+  # Only allow a list of trusted parameters through.
+  def assembly_params
+    params.require(:assembly).permit(:name, :part_id, :book_id)
+  end
 end
diff --git a/app/helpers/api/assemblies_helper.rb b/app/helpers/api/assemblies_helper.rb
new file mode 100644
index 0000000..6f5f4b0
--- /dev/null
+++ b/app/helpers/api/assemblies_helper.rb
@@ -0,0 +1,2 @@
+module Api::AssembliesHelper
+end
diff --git a/app/models/assembly.rb b/app/models/assembly.rb
index 8f06619..078f105 100644
--- a/app/models/assembly.rb
+++ b/app/models/assembly.rb
@@ -1,5 +1,6 @@
 class Assembly < ApplicationRecord
-  has_many :part, through: :assembly_parts
-  belongs_to :book
-  has_many :assembly_parts
+  has_and_belongs_to_many :part
+  has_one :book
+
+  validates :name, presence: true
 end
diff --git a/config/routes.rb b/config/routes.rb
index deac7cc..15a2514 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -12,5 +12,6 @@
     resources :suppliers
     resources :accounts
     resources :parts
+    resources :assemblies
   end
 end
diff --git a/db/migrate/20230714202258_create_assembly_parts.rb b/db/migrate/20230714202258_create_assemblies_parts.rb
similarity index 62%
rename from db/migrate/20230714202258_create_assembly_parts.rb
rename to db/migrate/20230714202258_create_assemblies_parts.rb
index 454bc45..8ab7a4f 100644
--- a/db/migrate/20230714202258_create_assembly_parts.rb
+++ b/db/migrate/20230714202258_create_assemblies_parts.rb
@@ -1,6 +1,6 @@
-class CreateAssemblyParts < ActiveRecord::Migration[7.0]
+class CreateAssembliesParts < ActiveRecord::Migration[7.0]
   def change
-    create_table :assembly_parts do |t|
+    create_table :assemblies_parts do |t|
       t.references :assembly, null: false, foreign_key: true
       t.references :part, null: false, foreign_key: true
 
diff --git a/db/seeds.rb b/db/seeds.rb
index 606804a..6cfaf66 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -5,31 +5,31 @@
 Account.destroy_all
 Part.destroy_all
 
-#Create Author
+# Create Author
 authors = []
 5.times do
   authors << Author.create(name: FFaker::Name.name, cpf: FFaker::IdentificationBR.cpf)
 end
 
-#create Supplier
+# create Supplier
 5.times do
   Supplier.create(name: FFaker::Company.name, cnpj: FFaker::IdentificationBR.cnpj)
 end
 
-#create Account
+# create Account
 suppliers_ids = Supplier.pluck(:id)
 
 suppliers_ids.each do |supplier_id|
   Account.create(digit: rand(1..50), account_number: rand(10_000..99_999).to_s, supplier_id:)
 end
 
-#create Part
-part_name = ["Hard Cover", "Soft Cover", "Premium Cover", "Dust Jacket", "Comic Book Cover",
-             "Standard Size Page", "Large Print Page", "Deckle Edge",
-             "Glossy Page", "Premium Paper Page",
-             "Recycled Paper Page", "Gilded Edge", "Endpapers",
-             "Header", "Footer", "Bookmark", "Binding", "Corner Cut",
-             "Fold", "Creases"]
+# create Part
+part_name = ['Hard Cover', 'Soft Cover', 'Premium Cover', 'Dust Jacket', 'Comic Book Cover',
+             'Standard Size Page', 'Large Print Page', 'Deckle Edge',
+             'Glossy Page', 'Premium Paper Page',
+             'Recycled Paper Page', 'Gilded Edge', 'Endpapers',
+             'Header', 'Footer', 'Bookmark', 'Binding', 'Corner Cut',
+             'Fold', 'Creases']
 
 part_name.each_slice(4).with_index do |name_slice, index|
   name_slice.each do |name|
@@ -37,3 +37,18 @@
                 supplier_id: suppliers_ids[index])
   end
 end
+
+# create assembly
+assemblies_descriptions = {
+  'paperback' => ['Soft Cover', 'Standard Size Page', 'Acid-free Page', 'Comic Book Cover', 'Bookmark'],
+  'hardcover' => ['Hard Cover', 'Dust Jacket', 'Acid-free Page', 'Large Print Page', 'Header'],
+  'deluxe edition' => ['Premium Cover', 'Glossy Page', 'Endpapers', 'Premium Paper Page', 'Footer'],
+  "collector's edition" => ['Hard Cover', 'Gilded Edge', 'Endpapers', 'Recycled Paper Page', 'Binding'],
+  'limited edition' => ['Premium Cover', 'Deckle Edge', 'Gilded Edge', 'Creases', 'Corner Cut', 'Fold']
+}
+
+assemblies_descriptions.each do |name, dscpts|
+  assembly_parts = dscpts.map { |dscpt| Part.find_by(name: dscpt) }.compact
+  assembly = Assembly.create(name:)
+  assembly_parts << assembly.part
+end
diff --git a/spec/models/assembly_part_spec.rb b/spec/models/assembly_part_spec.rb
deleted file mode 100644
index 2c85cdd..0000000
--- a/spec/models/assembly_part_spec.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe AssemblyPart, type: :model do
-  pending "add some examples to (or delete) #{__FILE__}"
-end
diff --git a/spec/requests/api/assemblies_spec.rb b/spec/requests/api/assemblies_spec.rb
new file mode 100644
index 0000000..a00048e
--- /dev/null
+++ b/spec/requests/api/assemblies_spec.rb
@@ -0,0 +1,7 @@
+require 'rails_helper'
+
+RSpec.describe "Api::Assemblies", type: :request do
+  describe "GET /index" do
+    pending "add some examples (or delete) #{__FILE__}"
+  end
+end