Middleware Stack

Slot Order

Runique applies middlewares in an optimal order using the slot system:

Incoming request
    ↓
1. Extensions (slot 0)     → Inject Tera, Config, Engine
2. ErrorHandler (slot 10)  → Capture and render errors
3. Custom (slot 20+)       → Custom middlewares
4. CSP (slot 30)           → Content Security Policy & headers
5. Cache (slot 40)         → No-cache in development
6. Session (slot 50)       → Session management
7. CSRF (slot 60)          → CSRF protection
8. Host (slot 70)          → Allowed Hosts validation
    ↓
Handler (your code)
    ↓
Outgoing response (middlewares in reverse order)

Important: With Axum, the last .layer() applied is executed first. The Intelligent Builder manages this order automatically.

Via Axum Extensions, automatically injected by the Extensions middleware:

// Automatically registered by the builder:
// Extension(engine)  → Arc<RuniqueEngine>
// Extension(tera)    → Arc<Tera>
// Extension(config)  → Arc<RuniqueConfig>

// Accessible inside handlers via Request:
pub async fn handler(request: Request) -> AppResult<Response> {
    let db = request.engine.db.clone();
    let config = &request.engine.config;
    // ...
}