What it is

Zappa is an open-source Python project for deploying serverless web applications and APIs on AWS. It lives in the Python web framework ecosystem and the AWS serverless ecosystem, with topic tags for Flask, Django, Pyramid, Bottle, AWS Lambda, API Gateway, and ALB. The project is distributed under the MIT license and is categorized as a developer tool for API development and testing.

The concrete problem it solves is the gap between ordinary Python web applications and AWS serverless infrastructure. Instead of asking a team to assemble Lambda functions, API Gateway routes, deployment packages, SSL certificates, scheduled events, and logging by hand, Zappa provides a command-line workflow and settings model for deploying, updating, rolling back, and operating Python applications as serverless services.

Key capabilities

• Zappa deploys Python web applications to AWS Lambda and API Gateway through a command-line interface that supports initial deployments, updates, rollback, undeploy, and packaging.
• It supports Flask, Django, Pyramid, and Bottle applications, including a documented Django management command workflow.
• It configures scheduled tasks with AWS EventBridge rules, including multiple expressions, disabled events, and custom rule naming.
• It provides operations commands for tailing logs, checking status, and invoking remote functions from the command line.
• It handles SSL certificate deployment through AWS Certificate Manager, Let's Encrypt with DNS or HTTP authentication, or user-supplied certificates.
• It supports local, remote AWS, and S3-backed environment variables, plus custom IAM roles for deployment and execution.

Who uses it and how

• Teams use Zappa to move Flask or Django applications onto AWS Lambda and API Gateway without maintaining conventional web servers.
• Developers use the Zappa CLI to create deployment settings, package the application, deploy it, update it, and roll back to a previous version.
• Operators schedule recurring Python tasks through EventBridge rules and invoke functions remotely for maintenance or processing workflows.

Getting started

Install Zappa from PyPI, then use the Zappa CLI to run initial setup, generate settings, and deploy the application. The README also describes Docker workflows and notes that some settings should not be used with Docker deployments.

When to use it — and when not to

Zappa fits Python web applications that already use a supported framework and that can run on AWS Lambda and API Gateway. It is a weaker fit when a team does not want to operate AWS-specific concerns such as IAM roles, EventBridge scheduling, SSL certificates, environment variables, and deployment packaging. Docker deployments require attention because the README identifies settings that should not be used with Docker workflows, and the documented limitations and constraints mean teams should validate current behavior against their own AWS setup.

$ pip install zappa
$ zappa init
$ zappa deploy