> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apivalk.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Coding Standards

> Apivalk follows modern PHP standards and clean code principles to ensure the framework remains lightweight, predictable, and easy to extend

## Language Level

* **PHP 7.2+**: We maintain compatibility with PHP 7.2 while using modern features where possible (like `declare(strict_types=1)` and return type hints).

## PHP Standards Recommendations (PSR)

* **PSR-1 & PSR-12**: We follow the basic and extended coding style guides.
* **PSR-4**: Autoloading is handled via PSR-4 namespaces.
* **PSR-11**: Container integration is based on the standard container interface.
* **PSR-7/15 (Inspired)**: While we use custom, optimized HTTP interfaces for performance and type-safety, our design is heavily inspired by these standards.

## Static Analysis

* **PHPStan Level 6**: We use PHPStan for static analysis to ensure code quality and type-safety. All core code must pass level 6 analysis.

## Core Principles

### Single Source of Truth (SSOT)

Documentation is code. Instead of separate Swagger files or messy annotations, the API structure is defined using PHP classes (`AbstractProperty`). This single definition drives validation, population, and documentation generation.

### Single Responsibility Principle (SRP)

* **Controllers**: Each controller should handle exactly one route and one HTTP method.
* **Requests**: Each request class defines the schema for exactly one endpoint.
* **Validators**: Each validator handles exactly one property type.

### Type Safety

Even in older PHP versions, Apivalk enforces strict typing. Data is validated and cast to the correct type before it reaches your business logic.

### Immutability

Response objects are designed to be built and returned. While not strictly immutable, we discourage modifying response state across many layers to avoid side effects.

## Clean Code Practices

* **Descriptive Naming**: Classes and methods are named clearly based on their intent (e.g., `GetPetController`, `StringProperty`).
* **Minimal Boilerplate**: We use automated discovery (via `ClassLocator`) to eliminate manual route registration.
* **Fail Fast**: Input is validated at the middleware level, before it ever reaches the controller.