PROPOSAL API (lambda_server)

```rust use anyhow::Result; use lambda_server::{Http, Context}; use serde::{Serialize, Deserialize}; use validator::{Validate, ValidationError};

[derive(Deserialize, Debug, Validate)]

struct Request { #[validate(range(min = 1))] pub price: i32, #[validate(range(min = 1))] pub quantity: i32, }

[derive(Serialize, Debug)]

struct Response { pub amount: i32, }

fn handler(ctx: Context, req: Request) -> Result { req.validate()?;

let amount = req.price * req.quantity;
Ok(Response{ amount })

}

[tokio::main]

async fn main() -> Result<()> { Http::run(handler).await?; Ok(()) } ```