Nexy

Nexy is a modular fullstack meta-framework designed to simplify modern web development. By bridging the gap between FastAPI backends and Vite-powered frontend ecosystems (React, Vue, Svelte, Solid.js), Nexy 2 allows you to build rich, interactive applications within a unified Python environment.

The Nexy 2 Vision

Nexy 2 transforms the development experience by masking complex architectural patterns behind an intuitive interface. The framework handles the orchestration between the Python server and the JavaScript client, allowing you to focus exclusively on business logic and UI.

Core Concepts

Mastering Nexy involves three essential pillars:

1. The .nexy Format (Polyglot Component)

While Nexy is fully functional for pure backend development (FastAPI-based APIs), the .nexy file is its powerful optional unit for building fullstack interfaces. It allows for a fluid composition of multiple languages:

• Header (Python): Defined within --- blocks, this is where you declare properties (prop) and import components (whether they are .nexy, .vue, .tsx, .mdx, or even Python functions).
• Template (HTML/Jinja2): The structure of your component, rendered server-side with the power of Jinja2.
• Script & Style (Optional): Integrate JavaScript/TypeScript or CSS (Tailwind native) directly into your component. These blocks are extracted and optimized by Vite.

---
# Definition Logic (Python)
title : prop[str] = "Nexy Component"
from "@/components/Card.nexy" import Card
from nexy import Vite  # Automatic asset injection
---
<!-- Server Rendering (Jinja2) -->
<div class="p-6 bg-white rounded-xl shadow-lg">
    <h1 class="text-2xl font-bold">{{ title }}</h1>
    <Card content="I can contain other components." />
</div>

<script>
    // Client Interactivity (Optional)
    // Managed by Vite with HMR support
    console.log("Nexy component hydrated");
</script>

2. Intelligent Hybrid Routing

Nexy scales with your project size:

• File-Based Routing: Your src/routes/ directory structure defines your URLs (e.g., index.nexy -> /).
• Module-Based Routing: For enterprise architectures, use a modular approach inspired by NestJS.
• Hybrid Rendering: Mix static pages and dynamic API routes within the same project.

3. Unified Ecosystem via Vite

Nexy is framework-agnostic. You can import and use React, Vue, Svelte, or Solid.js components directly within your Nexy templates. The Vite build pipeline handles everything, ensuring optimal performance and zero configuration.

Tooling and Development

Nexy CLI (nx)

The nx command-line tool centralizes your development workflow:

• nx dev: Starts both the FastAPI server and the Vite dev server in parallel.
• nx build: Compiles your assets for optimized production deployment.

VS Code Extension (Alpha)

A dedicated extension (LSP) is included in the repository (currently in Alpha) to provide a first-class development experience: real-time diagnostics, prop and import auto-completion, and contextual snippets.

Getting Started

Prerequisites

• Python 3.12+
• Node.js 18+

Installation

pip install nexy

Project Initialization

nexy init

The interactive assistant will help you choose your preferred frontend framework and enable Tailwind CSS.

Run

nx dev

Security and Reliability

• Strict Typing: Pydantic integration for robust data and prop validation.
• Native Protection: Automatic Jinja2 character escaping against XSS vulnerabilities.
• Architectural Integrity: Built on SOLID principles for long-term maintainability.

License

Nexy is open-source software licensed under the MIT License.