What reasons make JWT mandatory for authorization and authentication in modern applications?

JWT (JSON Web Token) has become mandatory in modern applications for authorization and authentication for several reasons:

• Stateless: JWT allows the server not to store sessions, as all user information and access rights are stored within the token itself.
• Scalability: The absence of the need to store sessions simplifies scaling applications, especially in distributed systems and microservices.
• Security: JWT is signed (for example, using HMAC or RSA), which guarantees the integrity and authenticity of the token.
• Ease of transmission: The token is compact and easily transmitted via HTTP headers, URLs, or cookies.
• Flexibility: Any necessary information (such as roles, expiration time) can be included in the payload.

Example of creating a JWT in Python using the PyJWT library:

import jwt
import datetime

payload = {
    'user_id': 123,
    'exp': datetime.datetime.utcnow() + datetime.timedelta(hours=1)
}
secret = 'your_secret_key'
token = jwt.encode(payload, secret, algorithm='HS256')
print(token)