【Rust】APIでBTC, ETHのUSD価格を取得する

use reqwest::Client;
use serde::{Serialize, Deserialize};
use serde_json::{Value};

#[tokio::main]
async fn main() {

    let btc: String = "BTC".to_string();
    let btc_price: Value = get_price(btc).await.unwrap();
    println!("{}", btc_price);

    let eth: String = "ETH".to_string();
    let eth_price: Value = get_price(eth).await.unwrap();
    println!("{}", eth_price);
}

async fn get_price(code: String) -> Result<Value, Box<dyn std::error::Error>> {
    let mut url:String = "https://api.coinbase.com/v2/exchange-rates?currency=".to_string();
    url.push_str(&code);
    let contents = reqwest::get(url).await?.text().await?;
    let res: Value = serde_json::from_str(&contents).unwrap();
    println!("{:?}", res["data"]["rates"]["USD"]);
    Ok((res["data"]["rates"]["USD"]).clone())
}

Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.97s
Running `target/debug/wallet`
String(“94359.295”)
“94359.295”
String(“3246.82”)
“3246.82”

処理速度が遅いが、取得はできる。
よし、さて、PoSでもやるか！