How to Use FastAPI with Redis: A Step-by-Step Guide

FastAPI is a modern web framework for building APIs with Python. It is based on Python type hints and is designed to be fast, easy to use, and efficient. Redis is an open-source, in-memory data structure store that can be used as a database, cache, and message broker. In this tutorial, we will show you how to integrate Redis with FastAPI to build a simple API that stores and retrieves data from a Redis database.

Step 1: Install FastAPI and Redis
First, you need to install FastAPI and Redis. You can install FastAPI using pip by running the following command:

pip install fastapi

Next, you can install Redis by following the instructions on the official Redis website (https://redis.io/). Make sure that Redis is running on your machine before proceeding to the next steps.

Step 2: Create a FastAPI app
Create a new Python file and import the necessary modules:

from fastapi import FastAPI

Create an instance of the FastAPI app:

app = FastAPI()

Step 3: Connect to Redis
To connect to Redis from your FastAPI app, you can use the aioredis library. Install the library using pip:

pip install aioredis

Import the library in your Python file:

import aioredis

Create a Redis connection:

redis = aioredis.from_url("redis://localhost")

Step 4: Define API endpoints
Now, you can define the API endpoints that will interact with the Redis database. For example, you can create an endpoint to store data in Redis:

@app.post("/data/{key}")
async def store_data(key: str, value: str):
    await redis.set(key, value)
    return {"message": "Data stored successfully"}

You can also create an endpoint to retrieve data from Redis:

@app.get("/data/{key}")
async def get_data(key: str):
    value = await redis.get(key)
    if value is None:
        return {"message": "Data not found"}
    return {"key": key, "value": value.decode()}

Step 5: Start the FastAPI app
Finally, you can start the FastAPI app by running the following command:

uvicorn app:app --reload

You can now access your FastAPI app at http://localhost:8000 and use the API endpoints to store and retrieve data from the Redis database.

In this tutorial, you learned how to integrate Redis with FastAPI to build a simple API that interacts with a Redis database. You can further enhance the app by adding more endpoints, implementing authentication and authorization, and handling errors. FastAPI and Redis provide a powerful combination for building high-performance web applications with Python.