FLARE,
IN DART.

A Flutter app could always reach Flare over JSON-RPC, and web3dart is a maintained, general purpose Dart EVM library that works against any Flare RPC. That has never been the gap.

What did not exist is anything Flare specific: typed, generated bindings for Flare's own contracts, so that FTSO feeds, FDC attestations, FAssets minting and Smart Accounts are reachable without hand-rolling ABIs against the registry.

That is the difference between a week of work and an import.

final wnat = await IWNatContract.resolve(client);

// Build. Only payable functions accept a value, so attaching one to a
// function that would reject it does not compile.
final tx = wnat.depositTx(value: BigInt.from(10).pow(18), from: user);

// Price. Simulates against current state, so a doomed action fails here,
// before the user is asked to approve it and before it costs anything.
final ready = await client.prepareTransaction(tx);
print(ready.maxCost);            // worst case, in wei

// Sign, with your wallet library. Not this package.
final hash = await wallet.request('eth_sendTransaction', [ready.toWalletJson()]);

// Confirm. A mined transaction is not a successful one.
final receipt = await client.waitForReceipt(hash);
if (!receipt.succeeded) { /* reverted, and still cost gas */ }

If it reverts after it is mined, the receipt will not tell you why: it has no field for it. Replaying the call at its own block does.

if (!receipt.succeeded) {
  final why = await client.explainRevert(receipt);
  print(why?.description); // "ERC20: transfer amount exceeds balance"
}

When something reverts before signing, you get the reason directly. That matters on Flare specifically, because 168 of the custom errors in the published ABIs carry no message at all, so the node reports them as four opaque bytes.

try {
  await client.prepareTransaction(tx);
} on FlareRpcException catch (e) {
  print(IAssetManagerContract.decodeRevert(e)?.description);
  // e.g. "InsufficientFundsForRedeem(1000000)"
}