Learn APIs in one hour [a hands on guide]

Mastering APIs could be your career game-changer.

Give me one hour, and I’ll show you how to get hands-on with APIs.

🌐 LinkedIn’s algorithm. Stripe’s payment system. Spotify’s song suggestions. What do they all have in common?

They run on APIs, the secret sauce that makes the modern digital world spin.

If you’re looking to build smarter products, understanding APIs is non-negotiable.

And in this week’s edition, you’ll not only grasp the fundamentals of APIs, you’ll also get hands-on with real API calls using Postman.

So grab your coffee ☕ and buckle up, we’re about to crack the API code!

It’s one of those terms you’ve heard thrown around by developers or read in a product brief, but maybe you never felt the need to dig deeper. Today we fix that, not with theory, but by actually making calls.

Step 1: API fundamentals (2 min) 🔍

Before jumping in, let’s cover the basics:

• API = a way for two applications to talk to each other.

• Endpoints: the doors 🚪 to the API that you knock on to get (or send) information.

• Requests: you ask the API for something, usually in one of these forms:

  • GET: grab some data 📝

  • POST: send data to create something new ✉️

  • PUT: update existing data 🔄

  • DELETE: remove data 🗑️

• Responses: the API’s reply, usually data in JSON format (you’ll see this in action shortly).

• Status codes: the API tells you if things went well (200 OK ✅) or wrong (404 Not Found ❌).

Ok, enough theory. Let’s get practical and explore an API in real-time.

Step 2: Make your first call, in the browser (10 min) 🌐

The fastest way to see an API is to hit a GET endpoint right in your browser. No tools needed.

Action: Paste this into a new browser tab and hit enter:

https://pokeapi.co/api/v2/pokemon/ditto

You just made a GET request. What came back is JSON, the structured text APIs use to talk. Messy at first glance, but look closer: it’s just labels and values ("name": "ditto", "weight": 40). That’s an API response.

Step 3: Level up with Postman (20 min) 🚀

The browser only does simple GETs. Postman lets you do everything, GET, POST, headers, the lot. Download it (it’s free), create an account, and open a new request tab.

Action: Make a GET request in Postman:

1. Set the method dropdown to GET

2. Paste this URL:

https://jsonplaceholder.typicode.com/todos/1

3. Hit Send

You’ll get back a clean JSON response and, in the corner, a status code:

{
  "userId": 1,
  "id": 1,
  "title": "delectus aut autem",
  "completed": false
}

See that 200 OK? That’s the API telling you the request worked. Congrats, you just used a real API client. 🎉

Step 4: Send data with POST (10 min) ✉️

GET grabs data. POST creates it. Let’s send some.

Action: In Postman:

1. Change the method to POST

2. Use this URL:

https://jsonplaceholder.typicode.com/posts

3. Go to the Body tab, choose raw, and pick JSON

4. Paste this in:

{
  "title": "My first API call",
  "body": "Learning APIs in an hour",
  "userId": 1
}

5. Hit Send

The API responds with 201 Created and echoes back your new object with an id. You just told a server to create something. That’s the same mechanism behind “submit”, “save”, and “post” buttons everywhere.

Step 5: Spot APIs in the wild (10 min) 🕵️

Now see how the products you use every day rely on APIs.

Action: Open any web app you love (your email, a dashboard, a social app). Open Chrome Developer Tools (right-click → Inspect), click the Network tab, filter to Fetch/XHR, then refresh the page.

Watch the flood of requests. Click one and you’ll see the endpoint, the method, the status code, and the JSON response, the exact same building blocks you just used in Postman. Every modern product is a web of API calls.

You went from “what’s an API?” to making GET and POST requests and reading real responses, in under an hour.

You don’t need to build APIs to be a great PM. But understanding them changes everything: you’ll write sharper specs, scope integrations realistically, and earn instant credibility with engineers.

Next time someone says “we’ll just hit their API”, you’ll know exactly what that means.

See you next week. 👋🏼