API Learning 101 🚀

Welcome to API Learning 101! This repository is your comprehensive guide to understanding and working with APIs, complete with a fully functional REST API backend and hands-on learning resources.

🌐 Live Demo

Backend API: api-learning.nisalgunawardhana.com

📚 What You'll Learn

This repository provides:

• Complete API fundamentals - HTTP methods, status codes, headers, REST principles
• Working backend API - Real API you can interact with
• Postman collection - Ready-to-use API tests
• Hands-on examples - Practical demonstrations
• Best practices - Industry-standard approaches

📂 Repository Structure

api-learning-101/
├── docs/
│   ├── 01-what-is-api.md
│   ├── 02-http-methods.md
│   ├── 03-status-codes.md
│   ├── 04-rest-principles.md
│   ├── 05-postman-guide.md
│   └── screenshots/
├── backend/
│   ├── api/
│   │   └── index.js
│   ├── data/
│   │   └── users.json
│   ├── package.json
│   └── README.md
├── postman/
│   └── API-Learning-101.postman_collection.json
├── .github/
│   ├── ISSUE_TEMPLATE/
│   └── workflows/
└── vercel.json

🚀 Quick Start

1. Access the Public Postman Collection

🌟 Postman Workspace: API Learning 101 Collection

1. Open the public Postman workspace link above
2. Fork the collection to your workspace
3. Start testing with the live API at https://api-learning.nisalgunawardhana.com

2. (Optional) Local Testing

If you want to test locally:

# Clone the repository
git clone https://github.com/nisalgunawardhana/api-learning-101.git
cd api-learning-101

# Install dependencies
cd backend
npm install

# Run locally
npm start

The API will be available at http://localhost:3000

🎯 API Endpoints

Base URL: https://api-learning.nisalgunawardhana.com

Method	Endpoint	Description
GET	/api/users	Get all users
GET	/api/users/:id	Get user by ID
POST	/api/users	Create new user
PUT	/api/users/:id	Update user
DELETE	/api/users/:id	Delete user
GET	/api/reset	Reset data to initial state

💡 Note about Data Persistence:

• The API uses in-memory storage (no database required!)
• Data persists during the serverless function's lifetime
• Changes are temporary and reset periodically on Vercel
• Use GET /api/reset to manually reload initial data
• Perfect for learning and testing without worrying about data cleanup!

📖 Learning Path

Follow these guides in order:

1. What is an API?
2. HTTP Methods
3. Status Codes
4. REST Principles
5. Postman Guide

🧪 Complete Testing Guide

Step 1: Access Postman Collection

1. Visit the public workspace: API Learning 101 Collection
2. Click Fork Collection to add it to your workspace
3. All requests are pre-configured with the production URL

Step 2: Test Each Request Type

You must test all request types and capture screenshots for submission:

🔍 GET Request - Fetch All Users

1. Select GET All Users from the collection
2. Click Send
3. Verify status code: 200 OK
4. Take a screenshot showing:
   • Request URL
   • Response status
   • Response body with user data

🔍 GET Request - Fetch Single User

1. Select GET User by ID from the collection
2. Replace :id with 1 in the URL
3. Click Send
4. Verify status code: 200 OK
5. Take a screenshot

➕ POST Request - Create User

1. Select POST Create User from the collection
2. Go to Body tab (raw JSON)
3. Use this sample data:

   {
     "name": "Your Name",
     "email": "yourname@example.com",
     "age": 25
   }

4. Click Send
5. Verify status code: 201 Created
6. Take a screenshot showing the created user with generated ID

✏️ PUT Request - Update User

1. Select PUT Update User from the collection
2. Use the ID from your created user
3. Update the data in Body:

   {
     "name": "Updated Name",
     "email": "updated@example.com",
     "age": 26
   }

4. Click Send
5. Verify status code: 200 OK
6. Take a screenshot showing the updated user

🗑️ DELETE Request - Remove User

1. Select DELETE User from the collection
2. Use the ID of the user you created
3. Click Send
4. Verify status code: 200 OK
5. Take a screenshot showing successful deletion message

Step 3: Organize Your Screenshots

Create a folder named screenshots-[your-github-username] with all 5 screenshots:

screenshots-yourusername/
├── 01-get-all-users.png
├── 02-get-single-user.png
├── 03-post-create-user.png
├── 04-put-update-user.png
└── 05-delete-user.png

Step 4: Submit Your Work

1. Add your screenshots to the docs/screenshots/ folder
2. Create a Pull Request with your screenshots
3. Go to Issues → New Issue
4. Select 📝 Submission template
5. Fill in:
   • Your name
   • GitHub username
   • PR number
   • T-shirt size (for winners only)
6. Submit the issue

Note: Your submission will be automatically assigned to @nisalgunawardhana for review. Once approved, you'll receive completion badges!

🎁 Social Media Bonus!

Increase your chances to win Postman swags:

1. Share your completion on Twitter/LinkedIn/Facebook
2. Tag @NisalGunawardhana and @Postman
3. Use hashtag #APILearning101
4. Winners will be selected randomly from all approved submissions!

🏆 Rewards & Badges

After successful submission and review:

Everyone receives:

• ✅ Submission Approved Badge
• 🎓 API Learning 101 Completion Badge

Random winners receive:

• 👕 Exclusive T-Shirt (winners selected randomly)
• 🎁 Chance for Postman Swags (share on social media for more chances!)

We've included a comprehensive Postman collection with pre-configured requests:

• ✅ All CRUD operations
• ✅ Pre-request scripts
• ✅ Tests for validation
• ✅ Environment variables

See the Postman Guide for detailed instructions.

💻 Backend Technology

• Runtime: Node.js
• Framework: Express.js
• Storage: JSON file (no database needed!)
• Hosting: Vercel

🤝 Contributing

We welcome contributions! Please submit your work:

1. Fork the repository
2. Create your feature branch
3. Make your changes
4. Submit a pull request
5. Create a submission issue

Your submission will be reviewed and you'll receive contributor badges!

📝 Submission Process

1. Complete your work and create a PR
2. Use the Submission issue template
3. Fill in all required details
4. Your submission will be automatically tagged and assigned for review
5. Receive your contributor badge upon approval! 🏆

🏆 Badges

Contributors receive badges based on their submissions:

• 🟡 Pending Review
• ✅ Approved
• 🎉 Closed/Completed

📄 License

MIT License - feel free to use this for learning!

👨‍💻 Maintainer

Nisal Gunawardhana (@nisalgunawardhana)

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Happy Learning! 🎉