Building Real-Time Applications with FastAPI and Apache Kafka

Adarsha Regmi
3 min readJul 14, 2023



In the era of real-time data processing, developers are constantly seeking efficient and scalable solutions to build applications that can handle high volumes of data. FastAPI, a modern Python web framework, and Apache Kafka, a distributed streaming platform, are two powerful tools that, when combined, enable developers to create robust real-time applications. In this article, we will explore how to integrate FastAPI with Apache Kafka and demonstrate its potential using a practical example.

  1. Understanding FastAPI and Apache Kafka:
  • FastAPI: An introduction to FastAPI, highlighting its key features such as high performance, simplicity, and support for modern Python features.
  • Apache Kafka: An overview of Apache Kafka’s role as a distributed streaming platform, capable of handling large-scale, real-time data streams.

2. Setting Up the Environment:

  • Installing FastAPI and Kafka: Step-by-step instructions on installing FastAPI and Apache Kafka on your local machine or in a development environment.

3. Integrating FastAPI with Apache Kafka:

  • Kafka Producer: Implementing a Kafka producer in FastAPI to publish data to a Kafka topic.

In this following code snippet, we import the necessary modules, create a FastAPI app, and initialize a Kafka producer. The publish route receives a topic and a message as input and publishes the message to the specified Kafka topic.

from fastapi import FastAPI
from kafka import KafkaProducer

app = FastAPI()
producer = KafkaProducer(bootstrap_servers='localhost:9092')"/publish/{topic}")
def publish(topic: str, message: str):
producer.send(topic, message.encode())
return {"status": "Message published successfully"}
  • Kafka Consumer: Building a Kafka consumer in FastAPI to consume data from the Kafka topic and process it in real-time.

In this code snippet, we import the required modules, create a FastAPI app, and initialize a Kafka consumer. The /consume route continuously consumes messages from the Kafka topic named "my_topic" and returns the messages as a response. In this example, we limit the response to 10 messages.

from fastapi import FastAPI
from kafka import KafkaConsumer

app = FastAPI()
consumer = KafkaConsumer("my_topic", bootstrap_servers='localhost:9092')

def consume():
messages = []
for message in consumer:
if len(messages) >= 10:
return {"messages": messages}

4. Building a Real-Time Application Example:

  • Scenario: Explaining a practical use case where real-time data processing is essential.
  • Architecture: Describing the application architecture, including FastAPI, Kafka, and the components involved.
  • Implementation: Walkthrough of the code implementation, demonstrating how FastAPI interacts with Kafka to process and display real-time data.
  • Testing: Steps to test the application and observe the real-time data flow.

5. Scaling and Deployment Considerations:

  • Scaling Kafka: Insights into scaling Apache Kafka to handle high data volumes and ensure fault tolerance.
  • Deployment Options: Discussing deployment options for FastAPI and Kafka, such as containerization with Docker or deploying on cloud platforms.

6. Conclusion:

  • Recap of the benefits and potential of integrating FastAPI with Apache Kafka for building real-time applications.
  • Encouragement to explore further possibilities and leverage the combined power of FastAPI and Apache Kafka.

By leveraging the capabilities of FastAPI and Apache Kafka, developers can create real-time applications that process and respond to high volumes of data with efficiency and scalability. Through the practical example presented in this article, you can gain hands-on experience integrating FastAPI with Kafka and unlock the potential for building your own real-time applications.

Remember, this integration opens doors to various use cases, from real-time analytics and monitoring to IoT applications and beyond. So, dive into the world of FastAPI and Apache Kafka, and embark on your journey to building powerful real-time applications!

I hope you find this article on integrating FastAPI with Apache Kafka informative and inspiring. If you have any further questions or need additional information, please feel free to reach out. Happy exploring and building real-time applications!