pezkuwi-subxt/subxt/examples/unstable_light_client_tx_basic.rs

use subxt::{client::LightClient, PolkadotConfig};
use subxt_signer::sr25519::dev;

// Generate an interface that we can use from the node's metadata.
#[subxt::subxt(runtime_metadata_path = "../artifacts/polkadot_metadata_small.scale")]
pub mod polkadot {}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // The smoldot logs are informative:
    tracing_subscriber::fmt::init();

    // Create a light client by fetching the chain spec of a local running node.
    // In this case, because we start one single node, the bootnodes must be overwritten
    // for the light client to connect to the local node.
    //
    // The `12D3KooWEyoppNCUx8Yx66oV9fJnriXwCcXwDDUA2kj6vnc6iDEp` is the P2P address
    // from a local polkadot node starting with
    // `--node-key 0000000000000000000000000000000000000000000000000000000000000001`
    let api = LightClient::<PolkadotConfig>::builder()
        .bootnodes([
            "/ip4/127.0.0.1/tcp/30333/p2p/12D3KooWEyoppNCUx8Yx66oV9fJnriXwCcXwDDUA2kj6vnc6iDEp",
        ])
        .build_from_url("ws://127.0.0.1:9944")
        .await?;

    // Build a balance transfer extrinsic.
    let dest = dev::bob().public_key().into();
    let balance_transfer_tx = polkadot::tx().balances().transfer_allow_death(dest, 10_000);

    // Submit the balance transfer extrinsic from Alice, and wait for it to be successful
    // and in a finalized block. We get back the extrinsic events if all is well.
    let from = dev::alice();
    let events = api
        .tx()
        .sign_and_submit_then_watch_default(&balance_transfer_tx, &from)
        .await?
        .wait_for_finalized_success()
        .await?;

    // Find a Transfer event and print it.
    let transfer_event = events.find_first::<polkadot::balances::events::Transfer>()?;
    if let Some(event) = transfer_event {
        println!("Balance transfer success: {event:?}");
    }

    Ok(())
}