JWT token creation in FastAPI - Mini Project: Build & Apply

JWT Token Creation with FastAPI

📖 Scenario: You are building a simple API that needs to create secure tokens for users after they log in. These tokens will help the API know who the user is without asking for their password every time.

🎯 Goal: Build a FastAPI app that creates a JWT token using a secret key and user data.

📋 What You'll Learn

Create a dictionary with user data

Add a secret key variable for signing the token

Use the jwt.encode function to create the token

Return the token in a FastAPI response

💡 Why This Matters

🌍 Real World

APIs use JWT tokens to securely identify users without sending passwords repeatedly. This keeps user sessions safe and efficient.

💼 Career

Understanding JWT token creation is essential for backend developers working on authentication and security in web applications.

1

Create user data dictionary

Create a dictionary called user_data with these exact entries: "sub": "user123" and "role": "admin".

FastAPI

# Create a dictionary called user_data with 'sub' and 'role' keys
# Your code here

Need a hint?

Think of user_data as a small card with user info that will go inside the token.

2

Add secret key variable

Add a variable called SECRET_KEY and set it to the string "mysecretkey123".

FastAPI

user_data = {"sub": "user123", "role": "admin"}
# Add a secret key variable called SECRET_KEY
# Your code here

Need a hint?

The secret key is like a password that only your API knows to keep tokens safe.

3

Create JWT token using jwt.encode

Import jwt from jose and create a variable called token by encoding user_data with SECRET_KEY using the algorithm HS256.

FastAPI

from jose import jwt

user_data = {"sub": "user123", "role": "admin"}
SECRET_KEY = "mysecretkey123"
# Create a JWT token called token using jwt.encode with user_data, SECRET_KEY, and algorithm 'HS256'
# Your code here

Need a hint?

Use jwt.encode to turn the user data into a secure token string.

4

Return token in FastAPI response

Import FastAPI and JSONResponse from fastapi. Create a FastAPI app called app. Add a GET route /token that returns a JSON response with the key "access_token" and the value token.

FastAPI

from jose import jwt
from fastapi import FastAPI
from fastapi.responses import JSONResponse

user_data = {"sub": "user123", "role": "admin"}
SECRET_KEY = "mysecretkey123"
token = jwt.encode(user_data, SECRET_KEY, algorithm="HS256")

# Create FastAPI app called app
# Add GET route '/token' that returns JSONResponse with {'access_token': token}
# Your code here

Need a hint?

This step makes your API give out the token when someone visits the /token URL.