Plain: A Human and Agent-Friendly Python Web Framework

Plain is a Python web framework designed to simplify app development for both humans and AI agents. It offers a familiar yet reimagined foundation, making it explicit, typed, and predictable. This approach ensures that what works well for humans also benefits agents. The framework supports integration with various agents like Codex, Amp, and OpenCode.

## Key Features

Plain's code structure is intuitive, with class-based views and a Router class for URLs, making it easy to manage app components. The framework includes built-in agent tooling, such as rules files that act as guardrails to prevent common mistakes, and comprehensive documentation accessible directly from the command line. It also supports end-to-end workflows triggered by slash commands, streamlining tasks like package installation, version upgrades, and performance optimization.

## Development and Production Tools

The framework is opinionated, relying on a stack that includes Python 3.13+, Postgres for databases, Jinja2 for templating, and htmx with Tailwind CSS for the frontend. It also incorporates various tools for development, such as uv for package management, ruff for linting and formatting, and pytest for testing. In production, Plain offers features like request tracing, security scanning, and analytics.

## Modular Packages

Plain is built on 30 first-party packages, each with built-in documentation. These packages cover a wide range of functionalities, from core framework elements like authentication and session storage to frontend components and development tools. This modularity allows developers to tailor the framework to their specific needs, whether they're building REST APIs, handling background jobs, or managing user authentication.

## Origin and Philosophy

Originating as a fork of Django, Plain is developed by PullApprove with the flexibility to adapt to the agentic era. It maintains the robust features of its predecessor while introducing innovations that cater to modern development needs. This makes Plain an attractive choice for developers looking to leverage both human and AI capabilities in their applications.