diff --git a/server/.gitignore b/server/.gitignore
index 30bc162..d049512 100644
--- a/server/.gitignore
+++ b/server/.gitignore
@@ -1 +1,2 @@
-/node_modules
\ No newline at end of file
+/node_modules
+/config
\ No newline at end of file
diff --git a/server/data/index.js b/server/data/index.js
deleted file mode 100644
index 4c6b4f9..0000000
--- a/server/data/index.js
+++ /dev/null
@@ -1,14 +0,0 @@
-const books = [
-  {
-    title: 'Harry Potter and the Chamber of Secrets',
-    author: 'J.K. Rowling',
-  },
-  {
-    title: 'Jurassic Park',
-    author: 'Michael Crichton',
-  },
-]
-
-module.exports = {
-  books,
-}
diff --git a/server/models/Book.js b/server/models/Book.js
deleted file mode 100644
index 3ed8271..0000000
--- a/server/models/Book.js
+++ /dev/null
@@ -1,11 +0,0 @@
-const { books } = require('../data/index')
-
-class Book {
-  static all() {
-    return books
-  }
-}
-
-module.exports = {
-  Book,
-}
diff --git a/server/models/Category.js b/server/models/Category.js
new file mode 100644
index 0000000..a59d1c8
--- /dev/null
+++ b/server/models/Category.js
@@ -0,0 +1,10 @@
+const mongoose = require('mongoose')
+
+const categorySchema = new mongoose.Schema({
+  title: String,
+  description: String,
+  createdAt: String,
+  updatedAt: String,
+})
+
+module.exports = mongoose.model('Category', categorySchema)
diff --git a/server/models/Todo.js b/server/models/Todo.js
new file mode 100644
index 0000000..ebdf775
--- /dev/null
+++ b/server/models/Todo.js
@@ -0,0 +1,11 @@
+const mongoose = require('mongoose')
+
+const todoSchema = mongoose.Schema({
+  title: String,
+  createdAt: String,
+  updatedAt: String,
+  status: String,
+  categoryId: String,
+})
+
+module.exports = mongoose.model('Todo', todoSchema)
diff --git a/server/models/index.js b/server/models/index.js
index 813f210..385b5c0 100644
--- a/server/models/index.js
+++ b/server/models/index.js
@@ -1,5 +1,7 @@
-const { Book } = require('./Book')
+const Todo = require('./Todo')
+const Category = require('./Category')
 
 module.exports = {
-  Book,
+  Todo,
+  Category,
 }
diff --git a/server/package-lock.json b/server/package-lock.json
index 12093b0..5dbb89d 100644
--- a/server/package-lock.json
+++ b/server/package-lock.json
@@ -869,6 +869,14 @@
       "integrity": "sha1-2Klr13/Wjfd5OnMDajug1UBdR3s=",
       "dev": true
     },
+    "config": {
+      "version": "3.3.1",
+      "resolved": "https://registry.npmjs.org/config/-/config-3.3.1.tgz",
+      "integrity": "sha512-+2/KaaaAzdwUBE3jgZON11L1ggLLhpf2FsGrfqYFHZW22ySGv/HqYIXrBwKKvn+XZh1UBUjHwAcrfsSkSygT+Q==",
+      "requires": {
+        "json5": "^2.1.1"
+      }
+    },
     "configstore": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/configstore/-/configstore-5.0.1.tgz",
@@ -1557,6 +1565,14 @@
       "integrity": "sha1-Wx85evx11ne96Lz8Dkfh+aPZqJg=",
       "dev": true
     },
+    "json5": {
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/json5/-/json5-2.1.3.tgz",
+      "integrity": "sha512-KXPvOm8K9IJKFM0bmdn8QXh7udDh1g/giieX0NLCaMnb4hEiVFqnop2ImTXCc5e0/oHz3LTqmHGtExn5hfMkOA==",
+      "requires": {
+        "minimist": "^1.2.5"
+      }
+    },
     "kareem": {
       "version": "2.3.1",
       "resolved": "https://registry.npmjs.org/kareem/-/kareem-2.3.1.tgz",
@@ -1683,8 +1699,7 @@
     "minimist": {
       "version": "1.2.5",
       "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.5.tgz",
-      "integrity": "sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw==",
-      "dev": true
+      "integrity": "sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw=="
     },
     "mongodb": {
       "version": "3.5.8",
diff --git a/server/package.json b/server/package.json
index 81a289b..44c735c 100644
--- a/server/package.json
+++ b/server/package.json
@@ -14,6 +14,7 @@
   },
   "dependencies": {
     "apollo-server": "^2.14.2",
+    "config": "^3.3.1",
     "graphql": "^15.0.0",
     "mongoose": "^5.9.18"
   }
diff --git a/server/readme.md b/server/readme.md
new file mode 100644
index 0000000..c0c7186
--- /dev/null
+++ b/server/readme.md
@@ -0,0 +1,16 @@
+# 🚀 GraphQL API
+
+### Start:
+```bash
+npm install
+npm start
+```
+
+### Enviroment variables:
+
+```json
+{
+  "db": "mongodb://localhost:27017", // db url
+  "port": 3001 // server port
+}
+```
diff --git a/server/resolvers/bookResolvers.js b/server/resolvers/bookResolvers.js
deleted file mode 100644
index f18ffbc..0000000
--- a/server/resolvers/bookResolvers.js
+++ /dev/null
@@ -1,11 +0,0 @@
-const { Book } = require('../models')
-
-const bookResolvers = {
-  Query: {
-    books: () => Book.all(),
-  },
-}
-
-module.exports = {
-  bookResolvers,
-}
diff --git a/server/resolvers/categoryResolvers.js b/server/resolvers/categoryResolvers.js
new file mode 100644
index 0000000..fa2a1dd
--- /dev/null
+++ b/server/resolvers/categoryResolvers.js
@@ -0,0 +1,31 @@
+const { Category, Todo } = require('../models')
+
+const categoryResolvers = {
+  Query: {
+    categories: () => Category.find({}),
+    category: (_, { id }) => Category.findById(id),
+  },
+  Mutation: {
+    createCategory: (_, { title, description }) => {
+      const category = new Category({
+        title,
+        description,
+        createdAt: new Date().toISOString(),
+        updatedAt: new Date().toISOString(),
+      })
+      return category.save()
+    },
+    deleteCategory: async (_, { id }) => {
+      const deletedCategory = await Category.findByIdAndRemove(id)
+      return deletedCategory
+    },
+    updateCategory: (_, { id, title, description }) => Category.findByIdAndUpdate(id, { $set: { title, description, updatedAt: new Date().toISOString() } }, { new: true })
+  },
+  Category: {
+    todos: ({ id }) => Todo.find({ categoryId: id }),
+  },
+}
+
+module.exports = {
+  categoryResolvers,
+}
diff --git a/server/resolvers/index.js b/server/resolvers/index.js
index 1bce0f3..8ef1659 100644
--- a/server/resolvers/index.js
+++ b/server/resolvers/index.js
@@ -1,6 +1,7 @@
-const { bookResolvers } = require('./bookResolvers')
+const { todoResolvers } = require('./todoResolvers')
+const { categoryResolvers } = require('./categoryResolvers')
 
-const resolvers = [bookResolvers]
+const resolvers = [todoResolvers, categoryResolvers]
 
 module.exports = {
   resolvers,
diff --git a/server/resolvers/todoResolvers.js b/server/resolvers/todoResolvers.js
new file mode 100644
index 0000000..fccc228
--- /dev/null
+++ b/server/resolvers/todoResolvers.js
@@ -0,0 +1,32 @@
+const { Todo, Category } = require('../models')
+
+const todoResolvers = {
+  Query: {
+    todos: () => Todo.find({}),
+    todo: (_, { id }) => Todo.findById(id),
+  },
+  Mutation: {
+    createTodo: (_, { title, categoryId }) => {
+      const todo = new Todo({
+        title,
+        createdAt: new Date().toISOString(),
+        updatedAt: new Date().toISOString(),
+        status: 'open',
+        categoryId,
+      })
+      return todo.save()
+    },
+    deleteTodo: async (_, { id }) => {
+      const deletedTodo = await Todo.findByIdAndRemove(id)
+      return deletedTodo
+    },
+    updateTodo: (_, { id, title, status, categoryId }) => Todo.findByIdAndUpdate(id, { $set: { title, updatedAt: new Date().toISOString(), status, categoryId } }, { new: true }),
+  },
+  Todo: {
+    category: ({ categoryId }) => Category.findById(categoryId),
+  },
+}
+
+module.exports = {
+  todoResolvers,
+}
diff --git a/server/server.js b/server/server.js
index 0c10e19..d7e0b22 100644
--- a/server/server.js
+++ b/server/server.js
@@ -2,14 +2,27 @@ const { ApolloServer } = require('apollo-server')
 const { typeDefs } = require('./typeDefs')
 const { resolvers } = require('./resolvers')
 
-const PORT = 3001
+const mongoose = require('mongoose')
+const config = require('config')
+const port = config.get('port')
 
 const startServer = async () => {
-  const server = new ApolloServer({ typeDefs, resolvers })
+  try {
+    const server = new ApolloServer({ typeDefs, resolvers })
+    await mongoose.connect(config.get('db'), {
+      useNewUrlParser: true,
+      useUnifiedTopology: true,
+      useFindAndModify: false,
+    })
 
-  server.listen(PORT, () => {
-    console.log(`Apollo server is running on port: ${PORT}`)
-  })
+    console.log('✔️  Database connected!')
+
+    server.listen({ port }).then(() => {
+      console.log(`Apollo server is running on port: ${port}!`)
+    })
+  } catch (err) {
+    console.log(`❌  Something went wrong: \n ${err}`)
+  }
 }
 
 startServer()
diff --git a/server/typeDefs/index.js b/server/typeDefs/index.js
index b17dc7d..0a9899a 100644
--- a/server/typeDefs/index.js
+++ b/server/typeDefs/index.js
@@ -1,7 +1,10 @@
 const { query } = require('./query')
-const { bookType } = require('./types/bookType')
+const { mutation } = require('./mutation')
 
-const typeDefs = [query, bookType]
+const { todoType } = require('./types/todoType')
+const { categoryType } = require('./types/categoryType')
+
+const typeDefs = [query, mutation, todoType, categoryType]
 
 module.exports = {
   typeDefs,
diff --git a/server/typeDefs/mutation.js b/server/typeDefs/mutation.js
new file mode 100644
index 0000000..ec16da6
--- /dev/null
+++ b/server/typeDefs/mutation.js
@@ -0,0 +1,19 @@
+const { gql } = require('apollo-server')
+
+const mutation = gql`
+  type Mutation {
+    # Todo mutations
+    createTodo(title: String!, categoryId: String!): Todo
+    deleteTodo(id: ID!): Todo
+    updateTodo(id: ID! title: String! status: String! categoryId: String!): Todo
+
+    # Category mutations
+    createCategory(title: String!, description: String!): Category
+    deleteCategory(id: ID!): Category
+    updateCategory(id: ID! title: String! description: String!): Category
+  }
+`
+
+module.exports = {
+  mutation
+}
\ No newline at end of file
diff --git a/server/typeDefs/query.js b/server/typeDefs/query.js
index f109763..0197367 100644
--- a/server/typeDefs/query.js
+++ b/server/typeDefs/query.js
@@ -2,7 +2,10 @@ const { gql } = require('apollo-server')
 
 const query = gql`
   type Query {
-    books: [Book]
+    todos: [Todo]
+    todo(id: ID!): Todo
+    categories: [Category]
+    category(id: ID!): Category
   }
 `
 
diff --git a/server/typeDefs/types/bookType.js b/server/typeDefs/types/bookType.js
deleted file mode 100644
index 673ca1a..0000000
--- a/server/typeDefs/types/bookType.js
+++ /dev/null
@@ -1,12 +0,0 @@
-const { gql } = require('apollo-server')
-
-const bookType = gql`
-  type Book {
-    title: String
-    author: String
-  }
-`
-
-module.exports = {
-  bookType,
-}
diff --git a/server/typeDefs/types/categoryType.js b/server/typeDefs/types/categoryType.js
new file mode 100644
index 0000000..50384ec
--- /dev/null
+++ b/server/typeDefs/types/categoryType.js
@@ -0,0 +1,16 @@
+const { gql } = require('apollo-server')
+
+const categoryType = gql`
+  type Category {
+    id: ID
+    title: String
+    description: String
+    createdAt: String
+    updatedAt: String
+    todos: [Todo]
+  }
+`
+
+module.exports = {
+  categoryType,
+}
diff --git a/server/typeDefs/types/index.js b/server/typeDefs/types/index.js
index dc8445b..ba5fafc 100644
--- a/server/typeDefs/types/index.js
+++ b/server/typeDefs/types/index.js
@@ -1,5 +1,7 @@
-const { bookType } = require('./bookType')
+const { todoType } = require('./todoType')
+const { categoryType } = require('./categoryType')
 
 module.exports = {
-  bookType,
+  todoType,
+  categoryType,
 }
diff --git a/server/typeDefs/types/todoType.js b/server/typeDefs/types/todoType.js
new file mode 100644
index 0000000..3f9535c
--- /dev/null
+++ b/server/typeDefs/types/todoType.js
@@ -0,0 +1,17 @@
+const { gql } = require('apollo-server')
+
+const todoType = gql`
+  type Todo {
+    id: ID
+    title: String
+    createdAt: String
+    updatedAt: String
+    status: String
+    categoryId: String
+    category: Category
+  }
+`
+
+module.exports = {
+  todoType,
+}