Project Structure

RustAPI projects follow a standard, modular structure designed for scalability.

my-api/
├── Cargo.toml          // Dependencies and workspace config
├── src/
│   ├── handlers/       // Request handlers (Controllers)
│   │   ├── mod.rs      
│   │   └── items.rs    // Example resource handler
│   ├── models/         // Data structures and Schema
│   │   ├── mod.rs      
│   ├── error.rs        // Custom error types
│   └── main.rs         // Application entry point & Router
└── .env.example        // Environment variables template

Key Files

src/main.rs

The heart of your application. This is where you configure the RustApi builder, register routes, and set up state.

src/handlers/

Where your business logic lives. Handlers are async functions that take extractors (like Json, Path, State) and return responses.

src/models/

Your data types. By deriving Schema, they automatically appear in your OpenAPI documentation.

src/error.rs

Centralized error handling. Mapping your AppError to ApiError allows you to simply return Result<T, AppError> in your handlers.