diff --git a/apps/api/.env b/apps/api/.env
index ecaf5a7c..0f84af61 100644
--- a/apps/api/.env
+++ b/apps/api/.env
@@ -1,3 +1,5 @@
+ENV=dev
+TRUSTED_ORIGINS=[]
 ACCESS_TOKEN_SECRET=[YOUR_ACCESS_TOKEN_SECRET_HERE]
 REFRESH_TOKEN_SECRET=[YOUR_REFRESH_TOKEN_SECRET_HERE]
-MONGO_URL=[YOUR_MONGO_CONNECTION_STRING_HERE]
\ No newline at end of file
+MONGO_URL=[YOUR_MONGO_CONNECTION_STRING_HERE]
diff --git a/apps/api/README.md b/apps/api/README.md
index f172a610..6066cc0e 100644
--- a/apps/api/README.md
+++ b/apps/api/README.md
@@ -21,34 +21,7 @@
 
 ## Challenges
 
-### Session 01
-
-- Create `route` for `posts` endpoint with the following methods:
-    - `GET /posts` Return an array of all the posts with status code 200
-    - `GET /posts/category/:category` Return an array of all the posts by category with status code 200
-    - `GET /posts/:id` Return a post by id with category object and each comment object in the array with status code 200
-    - `POST /posts` Create a new post and return the created post with status code 201
-    - `POST /posts/:id/comments` Create a comment inside the post and return the comment with status code 201
-    - `PATCH /posts/:id` Update post information and return the updated post with status code 200
-    - `DELETE /posts/:id` Delete the post and return the deleted post with status code 200 or 204 if you decide to not return anything
-    * *Add 404 validation where needed*
-
-- Post model
-    - id: string
-    - title: string
-    - image: string
-    - description: string
-    - category: string *Id of the category*
-    - comments: array *Array of comment ids*
-
-- Comment model
-    - id: string
-    - author: string
-    - content: string
-
-### Session 02
-
-- Refactor the code from last session to add a post controller
+### Session *
 
 ## How to
 
diff --git a/apps/api/src/config/.gitkeep b/apps/api/src/config/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/apps/api/src/config/corsConfig.ts b/apps/api/src/config/corsConfig.ts
index 045cf517..dd2e6594 100644
--- a/apps/api/src/config/corsConfig.ts
+++ b/apps/api/src/config/corsConfig.ts
@@ -1,15 +1,10 @@
-const allowedOrigins = ['http://localhost:4200', 'http://localhost:3000'];
-
-export const corsOptions = {
-  origin: (origin, callback) => {
-    // Note: origin will be undefined from same route in local development
-    if (allowedOrigins.indexOf(origin) !== -1 || !origin) {
-      callback(null, true);
-    } else {
-      callback(new Error('Not allowed by CORS'));
-    }
-  },
-  optionsSuccessStatus: 200
-};
-
-export default { corsOptions };
+export const corsOptions = {
+  origin: (origin, callback) => {
+    if (process.env.ENV === "dev" || process.env.TRUSTED_ORIGINS.includes(origin)) {
+      return callback(null, true)
+    }
+
+    callback(new Error("Not Allowed By Cors"))
+  },
+  OptionsSuccessStatus: 200
+}
diff --git a/apps/api/src/controllers/.gitkeep b/apps/api/src/controllers/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/apps/api/src/controllers/category.ts b/apps/api/src/controllers/category.ts
index 59294b96..999663f1 100644
--- a/apps/api/src/controllers/category.ts
+++ b/apps/api/src/controllers/category.ts
@@ -1,110 +1,69 @@
-// Initialize categories array to save data in memory
-const categories = [];
-
-export const getCategory = (id: string) => {
-  return categories.find((p) => p.id === id);
-};
-
-// Get all categories
-const getCategories = (req, res) => {
-  // Return all the categories with a 200 status code
-  res.status(200).json(categories);
-};
-
-// Get category by id
-const getCategoryById = (req, res) => {
-  // Retrieve the id from the route params
-  const { id } = req.params;
-  // Check if we have a category with that id
-  const category = getCategory(id);
-
-  if (!category) {
-    // If we don't find the category return a 404 status code with a message
-    return res.status(404).json({ message: 'Category not found' });
-    // Note: Remember that json method doesn't interrupt the workflow
-    // therefore is important to add a "return" to break the process
-  }
-
-  // Return the category with a 200 status code
-  res.status(200).json(category);
-};
-
-// Create category
-const createCategory = (req, res) => {
-  // Retrieve the name from the request body
-  const { name } = req.body;
-
-  if (!name) {
-    // If name is empty or undefined return a 400 status code with a message
-    return res.status(400).json({ message: 'The name is required.' });
-  }
-
-  // Generate a new category
-  const newCategory = {
-    id: Date.now().toString(), // Convert id to string to match the value in get by id endpoint
-    name
-  };
-  // Add the new category to our array
-  categories.push(newCategory);
-
-  // Return the created category with a 201 status code
-  res.status(201).json(newCategory);
-};
-
-// Update category
-const updateCategory = (req, res) => {
-  // Retrieve the id from the route params
-  const { id } = req.params;
-  // Retrieve the index of the category in the array
-  const categoryIndex = categories.findIndex((p) => p.id === id);
-
-  // "findIndex" will return -1 if there is no match
-  if (categoryIndex === -1) {
-    // If we don't find the category return a 404 status code with a message
-    return res.status(404).json({ message: 'Category not found' });
-  }
-
-  // Generate a copy of our cateogory
-  const updatedCategory = { ...categories[categoryIndex] };
-  // Retrieve the name from the request body
-  const { name } = req.body;
-
-  // Check if we have a name, if so update the property
-  if (name) {
-    updatedCategory.name = name;
-  }
-
-  // Update the category in our array
-  categories[categoryIndex] = updatedCategory;
-
-  // Return the updated category with a 200 status code
-  res.status(200).json(updatedCategory);
-};
-
-// Delete category
-const deleteCategory = (req, res) => {
-  // Retrieve the id from the route params
-  const { id } = req.params;
-  // Retrieve the index of the category in the array
-  const categoryIndex = categories.findIndex((p) => p.id === id);
-
-  // "findIndex" will return -1 if there is no match
-  if (categoryIndex === -1) {
-    // If we don't find the category return a 404 status code with a message
-    return res.status(404).json({ message: 'Category not found' });
-  }
-
-  // Remove the category from the array
-  categories.splice(categoryIndex, 1);
-
-  // Return a 204 status code
-  res.status(204).send();
-};
-
-export default {
-  getCategories,
-  getCategoryById,
-  createCategory,
-  updateCategory,
-  deleteCategory
-};
+import type { Category } from "../models/types"
+
+export const categories: Category[] = []
+
+const findCategory = (id: string): Category | void => {
+  return categories.find(el => el.id === id)
+}
+
+const getCategory = (req, res): void => {
+  const { id } = req.params;
+  const currentCategory = findCategory(id)
+
+  if (!currentCategory) return res.status(404).json({message: "Category not found"})
+
+  res.status(200).json(currentCategory);
+}
+
+const updateCategory = (req, res) => {
+  const { id } = req.params;
+  const categoryIndex = categories.findIndex(el => el.id === id)
+  if (categoryIndex < 0) return res.status(404).json({message: "Category not found"})
+
+  const { name } = req.body;
+  if (!name) return res.status(401).json({ message: "Name is required!" })
+
+  categories[categoryIndex].name = name;
+
+  res.status(203).json(categories[categoryIndex]);
+}
+
+const deleteCategory = (req, res) => {
+  const { id } = req.params;
+  const categoryIndex = categories.findIndex(el => el.id === id)
+  if (categoryIndex < 0) return res.status(404).json({message: "Category not found"})
+
+  const currentCategory = categories[categoryIndex]
+
+  categories.splice(categoryIndex, 1)
+
+  res.status(200).json({status: "Item Deleted", item: currentCategory});
+}
+
+
+const getAllCategories = (req, res) => {
+  res.status(200).json(categories);
+}
+
+const createCategory = (req, res) => {
+  const { name } = req.body;
+
+  if (!name) return res.status(401).json({ message: "Name is required!" })
+
+  const newCategory: Category = {
+    id: Date.now().toString(),
+    name
+  }
+
+  categories.push(newCategory)
+
+  res.status(201).json(newCategory)
+}
+
+export default {
+  getCategory,
+  updateCategory,
+  deleteCategory,
+  getAllCategories,
+  createCategory,
+}
diff --git a/apps/api/src/controllers/post.ts b/apps/api/src/controllers/post.ts
new file mode 100644
index 00000000..c883316a
--- /dev/null
+++ b/apps/api/src/controllers/post.ts
@@ -0,0 +1,143 @@
+import type { Post, Comment, PostResponse } from "../models/types"
+import { categories } from "../controllers/category"
+
+const posts: Post[] = []
+const comments: Comment[] = []
+
+const buildResponsePost = (post: Post): PostResponse => {
+  return {
+    ...post,
+    category: categories.filter(cat => post.category.includes(cat.id)),
+    comments: comments.filter(com => post.category.includes(com.id))
+  } as PostResponse
+}
+
+const findPost = (id: string): Post | void => {
+  return posts.find(el => el.id === id)
+}
+
+const getPost = (req, res): void => {
+  const { id } = req.params;
+  const currentPost = findPost(id)
+
+  if (!currentPost) return res.status(404).json({message: "Post not found"})
+
+  res.status(200).json(buildResponsePost(currentPost));
+}
+
+const updatePost = (req, res) => {
+  const { id } = req.params;
+  const postIndex = posts.findIndex(el => el.id === id)
+  if (postIndex < 0) return res.status(404).json({message: "Post not found"})
+
+  const post = req.body;
+  if (!post) return res.status(401).json({ message: "Name is required!" })
+
+  Object.keys(post).forEach(key => {
+    if (!posts[postIndex][key]) return
+    posts[postIndex][key] = post[key]
+  })
+
+  res.status(203).json(buildResponsePost(posts[postIndex]));
+}
+
+const deletePost = (req, res) => {
+  const { id } = req.params;
+  const postIndex = categories.findIndex(el => el.id === id)
+  if (postIndex < 0) return res.status(404).json({message: "Post not found"})
+
+  const currentPost = buildResponsePost(posts[postIndex])
+
+  posts.splice(postIndex, 1)
+
+  res.status(200).json({status: "Item Deleted", item: currentPost});
+}
+
+const createComment = (req, res) => {
+  const { id } = req.params;
+  const currentPost = findPost(id)
+  if (!currentPost) return res.status(404).json({message: "Post not found"})
+
+  const {comment} = req.body;
+  if (!comment.author || !comment.content) return res.status(401).json({ message: "Invalid Comment!" })
+
+  const commentId = Date.now().toString()
+  comments.push({
+    id,
+    author: comment.author,
+    content: comment.content,
+  })
+
+  currentPost.comments.push(commentId)
+
+  res.status(203).json(buildResponsePost(currentPost));
+}
+
+
+const getAllPosts = (req, res) => {
+  res.status(200).json(posts.map(post => buildResponsePost(post)));
+}
+
+const createPost = (req, res) => {
+  const {
+    title,
+    image,
+    description,
+    category,
+    comments,
+  } = req.body;
+
+  if (
+    !title
+    || !image
+    || !description
+    || !category
+  ) return res.status(401).json({ message: "Invalid Post!" })
+
+  const newComments: string[] = []
+
+  comments.forEach(({author, content}) => {
+    if (!author || !content) res.status(401).json({ message: "Invalid Comment!" })
+
+    const id = Date.now().toString()
+
+    newComments.push(id)
+
+    comments.push({
+      id,
+      author,
+      content,
+    })
+  });
+
+  const newPost: Post = {
+    ...req.body,
+    id: Date.now().toString(),
+    comments: newComments,
+  }
+
+  posts.push(newPost)
+
+  res.status(201).json(buildResponsePost(newPost))
+}
+
+const getAllPostsByCategory = (req, res): void => {
+  const { category } = req.params;
+  let categoryPosts = posts.filter(post => post.category.includes(category))
+
+  if (!categoryPosts.length) return res.status(404).json({message: "Category has no posts"})
+
+  categoryPosts = categoryPosts.map(post => buildResponsePost(post))
+
+  res.status(200).json(categoryPosts);
+}
+
+export default {
+  getPost,
+  updatePost,
+  deletePost,
+  createComment,
+  getAllPosts,
+  createPost,
+  getAllPostsByCategory
+}
diff --git a/apps/api/src/main.ts b/apps/api/src/main.ts
index 7f6b1e10..3eec0782 100644
--- a/apps/api/src/main.ts
+++ b/apps/api/src/main.ts
@@ -1,21 +1,26 @@
-import cors from 'cors';
 import express from 'express';
 import helmet from 'helmet';
+import cors from 'cors';
 
 import { corsOptions } from './config/corsConfig';
-
 import categories from './routes/categories';
+import posts from './routes/posts';
 
 const host = process.env.HOST ?? 'localhost';
 const port = process.env.PORT ? Number(process.env.PORT) : 3000;
 
 const app = express();
 
-app.use(express.json());
-app.use(helmet());
-app.use(cors(corsOptions));
+app.use(express.json())
+app.use(helmet())
+app.use(cors(corsOptions))
 
-app.use('/api/categories', categories);
+app.use('/api/post', posts)
+app.use('/api/categories', categories)
+
+app.get('/', (req, res) => {
+  res.send({ message: 'Hello MFEE!' });
+});
 
 app.listen(port, host, () => {
   console.log(`[ ready ] http://${host}:${port}`);
diff --git a/apps/api/src/models/types.ts b/apps/api/src/models/types.ts
new file mode 100644
index 00000000..09904544
--- /dev/null
+++ b/apps/api/src/models/types.ts
@@ -0,0 +1,24 @@
+export type Category = {
+  id: string,
+  name: string;
+}
+
+export type Comment = {
+  id: string
+  author: string
+  content: string
+}
+
+export type Post = {
+  id: string
+  title: string
+  image: string
+  description: string
+  category: Category['id'][]
+  comments: Comment['id'][]
+}
+
+export type PostResponse = Post & {
+  category: Category[]
+  comments: Comment[]
+}
diff --git a/apps/api/src/routes/.gitkeep b/apps/api/src/routes/.gitkeep
new file mode 100644
index 00000000..e69de29b
diff --git a/apps/api/src/routes/categories.ts b/apps/api/src/routes/categories.ts
index 78e120a1..1573de98 100644
--- a/apps/api/src/routes/categories.ts
+++ b/apps/api/src/routes/categories.ts
@@ -1,22 +1,16 @@
-import express from 'express';
-
-import categoryController from '../controllers/category';
-
-const router = express.Router();
-
-// Get all categories
-router.get('/', categoryController.getCategories);
-
-// Get category by id
-router.get('/:id', categoryController.getCategoryById);
-
-// Create category
-router.post('/', categoryController.createCategory);
-
-// Update category
-router.patch('/:id', categoryController.updateCategory);
-
-// Delete category
-router.delete('/:id', categoryController.deleteCategory);
-
-export default router;
+import express from 'express';
+import categoryController from '../controllers/category';
+
+const router = express.Router();
+
+router.route('/:id')
+  .get(categoryController.getCategory)
+  .patch(categoryController.updateCategory)
+  .delete(categoryController.deleteCategory)
+
+
+router.route('/')
+  .get(categoryController.getAllCategories)
+  .post(categoryController.createCategory)
+
+export default router
diff --git a/apps/api/src/routes/posts.ts b/apps/api/src/routes/posts.ts
new file mode 100644
index 00000000..313bd76f
--- /dev/null
+++ b/apps/api/src/routes/posts.ts
@@ -0,0 +1,21 @@
+import express from 'express';
+import postController from '../controllers/post';
+
+const router = express.Router();
+
+router.route('/:id')
+  .get(postController.getPost)
+  .patch(postController.updatePost)
+  .delete(postController.deletePost)
+
+router.route("/:id/comments")
+  .post(postController.createComment)
+
+router.route('/')
+  .get(postController.getAllPosts)
+  .post(postController.createPost)
+
+router.route("/category/:category")
+  .get(postController.getAllPostsByCategory)
+
+export default router