# 4. Quick Start
WebIO provides a highly flexible routing system. These examples demonstrate a basic server using the **4-1. Closure Pattern** for rapid development and the **4-2. Handler Pattern** for structured, modular applications.
## 4-1. Closure Pattern
The closure pattern allows for defining logic directly within the route registration. This approach is ideal for maintaining full engine control with minimal boilerplate in smaller projects.
```rust,no_run
use webio::*;
fn main() {
let mut app = WebIo::new();
app.route(GET, "/", |_, _| async {
Reply::new(StatusCode::Ok)
.header("Content-Type", "text/plain; charset=UTF-8")
.body("Hello from 🦅 WebIO!")
});
app.run("127.0.0.1", "8080");
}
```
## 4-2. Handler Pattern
The handler pattern isolates logic into dedicated `async` functions. This is the recommended approach for production-grade applications to ensure the codebase remains clean and testable.
```rust,no_run
use webio::*;
// Logic isolated into a dedicated handler function
async fn hello_handler(_req: Req, _params: Params) -> Reply {
Reply::new(StatusCode::Ok)
.header("Content-Type", "text/html; charset=UTF-8")
.body("<h1>Hello from 🦅 WebIO!</h1>")
}
fn main() {
let mut app = WebIo::new();
// Register the handler by name
app.route(GET, "/", hello_handler);
app.run("127.0.0.1", "8080");
}
```
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