Web API Services Beginners Guide
Tags: api, codenewbie, webdev, javascript
Published: 2023-09-19 04:00:28

## What is Web API?

Web API is a set of rules and protocols that allow different software applications to communicate and interact with each other on the Internet. It acts as an intermediary that allows your application to request and receive data or perform actions on a remote server.

Think of Web API as a menu in a restaurant. You (client) have a list of options (API endpoint) and can order (send requests) special flavors to the kitchen (server) to get the food (data or service) you want. The menu (API docs) tells you what flavors are available and how to order them.

## How to create a simple web API

Let's dive into creating a basic Web API using Python and the Flask framework. Flask is a lightweight web framework that makes API development easy.

### Prerequisites:
- Python (install if not already installed)
- Flask (install using "pip install Flask")

### Creating a Minimal Web API

Create a new Python file, for example app.py, and add the following code:

```Python
imported bottles

application = Flask(__name__)

@app.route('/hello', method = ['GET'])
def hello_world():
    'Hello World!'

if __name__ == '__main__':
    app.run(config = True);
```

Here's what this code does:

1. We import the Flask library and create a Flask web application.

2. We define the "hello" route using the "@app.route" decorator. This route responds to an HTTP GET request and says 'Hello, World!' He regained his track.

3. Finally, there is an option to edit the program.

### Enable Web API

To run the Web API, open a terminal, navigate to the "app.py" folder, and do:

```
python.py application
```

You can access your API from "http://localhost:5000/hello". Open a web browser or use a tool like Mail to access this URL, click "Hello, World!" displayed.

## How Web API works

Web API uses HTTP (Hypertext Transfer Protocol) for communication. They follow several conventions, such as HTTP methods (GET, POST, PUT, DELETE) and status codes (200, 404, 500), to communicate information between the client and the server.

Some of the main components of a Web API request are:

- **HTTP Method**: Defines the action to be performed on the resource. Common methods are GET (get data), POST (create data), PUT (update data) and DELETE (delete data).

- **Endpoint URL**: The unique URL that clients use to access specific resources on the server. For example, "/hello".

- **metadata**: Metadata sent with the request, often used for authentication, content type negotiation, or other purposes.

- **Request Body**: For some methods like POST and PUT, data can be sent to the request body. Usually in JSON or XML format.

- **Response**: The server's response to the request. It includes the HTTP status code, headers, and response body (usually in JSON or XML).

## Test the API

You can use a web browser, a tool like Postman, or a command line tool like curl to test the API. For example, you can use "curl" to send a GET request to the API:

```head
scroll http://localhost:5000/hello
```

"Hello World!" You should get an answer.

## The results

Web APIs are the backbone of modern web applications, allowing them to communicate with remote servers and access data or services. Building a basic Web API is a good starting point to understand how it works.