Working with APIs: What they are and why every programmer should be able to use them

What is an API anyway?

Imagine you have a restaurant. In the kitchen, there are chefs who can cook everything, but visitors are not allowed inside the kitchen. And to order a dish, you have Waiter - he accepts the order, passes it to the kitchen and brings the result.

This "waiter" is API (Application Programming Interface) - an interface for communication between programs. The API says, "Here's what you can ask for, here's how to do it, and what you'll get in return."

Real-life example

You use a weather app — it shows the temperature and forecast. But where does it get the data? From the weather service API (for example, OpenWeather).

https:// api.openweathermap.org/data/2.5/weather?q=Paris&appid

And receives a response in JSON format:

{
  "main": { "temp": 18.4 },
  "weather": [{ "description": "clear sky" }]
}

Then the developer simply displays this data beautifully in the interface.

Why is API the basis of modern code?

API is a way to make different systems to work together.

Without it:

• your application will not know who is authorized (OAuth API);

• will not be able to get data (REST API);

• will not send a message to Telegram (Telegram Bot API);

• and will not even connect to the database (internal API driver).

Today, everything from payments and cards to music and neural networks is done with the help of APIs.

Why should every programmer be able to work with the API?

1. You can use other people's opportunities.

   Why invent your own payment method if you can connect Stripe or YooMoney?

2. You automate the routine.

   The API allows you to write scripts that take data from CRM, send reports or create tasks automatically.

3. You are expanding your projects.

   Add weather, currencies, news, translator, map — all this is done through the API.

4. You become a universal developer.

   Understanding the API is necessary for a web developer, a mobile developer, and even a game designer.

   

Where can I find the API?

How does it look in the code (in Python)?

import requests

city = "Paris"
api_key = "your_api_key"

url = f"https://api.openweathermap.org/data/2.5/weather?q={city}&appid={api_key}&units=metric"
response = requests.get(url)

data = response.json()
print("Temperature:", data["main"]["temp"], "°C")

It's simple: you you send a request → you get an answer → you use the data.

About keys and security

Almost all APIs require access key — as a pass to the system. You can't publish it openly, especially in public repositories. To do this, use .env files and environment variables.

API_KEY=12345abcd

import os
api_key = os.getenv("API_KEY")

REST, GraphQL, and WebSocket are three ways to communicate

• REST — a classic, where you get data by URL.

• GraphQL — more flexible: you choose which fields you need.

• WebSocket — needed for real-time updates (e.g. chats).

API is the glue that connects the entire digital world. If you know how to work with it, you can create smart, dynamic and useful apps.

And if not, it's time to start. Even a simple "request the weather and show it in the console" is already the first step into the world of integrations.

You can study the base in Codice — take simple, easy-to-understand programming lessons and master key topics step by step: from variables and loops to working with APIs and algorithms.
And if you want to discuss ideas, ask a question or just chat with those who are also studying - come to our Telegram channel. There is a lively community, discussions, news and support for like-minded people.

🧠 : What APIs have you already worked with or would you like to try? Write in the comments — we will collect the top of the most interesting!