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Update the Wallet

The fact that Wollet does have access to internet is a deliberate choice. This allows Wollet to work offline, where they can generate addresses.

The connection is handled by a specific component, a Blockchain Client. Blockchain clients connect to the specified server a fetch the wallet data from the blockchain.

LWK currently support 3 types of servers:

  • Electrum Servers
  • Esplora Servers
  • Waterfalls Servers

To delve into their differences and strength points see our dedicated section.

Create a Client

In this guide we will use an EsploraClient.

You can create a new client with EsploraClient::new(), specifying the URL of the service.

Scan the Blockchain

Given a Wollet you can call EsploraClient::full_scan(), which performs a series of network calls that scan the blockchain to find transactions relevant for the wallet.

EsploraClient::full_scan() has a stopping mechanisms that relies on BIP44 GAP LIMIT. This might not fit every use cases. In case you have large sequences of consecutive unused addresses you can use EsploraClient::full_scan_to_index().

Apply the Update

EsploraClient::full_scan() fetches, parses, (locally) unblind and serialized the fetched data in returned value, an Update. The Update can be applied to the Wollet using Wollet::apply_update().

After applying the update the wollet data will include the new transaction downloaded, for instance more transactions can be returned and balance can increase (or decrease).

Rust
use lwk_wollet::clients::blocking::EsploraClient;

// let url = "https://blockstream.info/liquidtestnet/api";
// let url = "https://blockstream.info/liquid/api";

let mut client = EsploraClient::new(&url, network)?;

if let Some(update) = client.full_scan(&wollet)? {
    wollet.apply_update(update)?;
}
Python
url = "https://blockstream.info/liquidtestnet/api"
client = EsploraClient(url, network)

update = client.full_scan(wollet)
wollet.apply_update(update)
Javascript
const url = "https://waterfalls.liquidwebwallet.org/liquidtestnet/api";
const client = new lwk.EsploraClient(network, url, true, 4, false);

const update = await client.fullScan(wollet);
if (update) {
    wollet.applyUpdate(update);
}

Next: Create a transaction