Attribute Macro attribute 

#[attribute]

Extracts a specific attribute value into a variable.

This attribute macro retrieves a specific attribute by key and makes it available as a typed variable from the request context.

Usage

use hyperlane::*;
use hyperlane_macros::*;
use serde::Deserialize;

const USER_KEY: &str = "user_data";

#[derive(Deserialize, Clone)]
struct User {
    id: u64,
    name: String,
}

#[attribute(USER_KEY => user: User)]
async fn handle_with_attribute(ctx: Context) {
    if let Some(user_data) = user {
        // Use the extracted attribute
    }
}

The macro accepts a key-to-variable mapping in the format key => variable_name: Type. The variable will be available as an Option<Type> in the function scope.