//! Example of using the WS provider to subscribe to new blocks.

use alloy::providers::{Provider, ProviderBuilder, WsConnect};

use eyre::Result;

use futures_util::StreamExt;

#[tokio::main]

async fn main() -> Result<()> {

// Create the provider.

let rpc_url = "wss://eth-mainnet.g.alchemy.com/v2/your-api-key";

let ws = WsConnect::new(rpc_url);

let provider = ProviderBuilder::new().on_ws(ws).await?;

// Subscribe to new blocks.

let sub = provider.subscribe_blocks().await?;

// Wait and take the next 4 blocks.

let mut stream = sub.into_stream().take(4);

println!("Awaiting block headers...");

// Take the stream and print the block number upon receiving a new block.

let handle = tokio::spawn(async move {

while let Some(header) = stream.next().await {

println!("Latest block number: {}", header.number);

}

});

handle.await?;

Ok(())

}