btcpayserver/BTCPayServer/Views/UIWallets/WalletSendVault.cshtml

@using BTCPayServer.Blazor.VaultBridge
@using BTCPayServer.Hosting
@model WalletSendVaultModel
@{
    var walletId = Context.GetRouteValue("walletId")?.ToString() ?? "";
	Model.ReturnUrl ??= Url.WalletTransactions(walletId);
    Layout = "_LayoutWizard";
    ViewData.SetActivePage(WalletsNavPages.Send, StringLocalizer["Sign the transaction"], walletId);
    this.ViewData.SetBlazorAllowed(true);

    // Calculate maximum PSBT size accounting for SignalR message overhead
    var blazorMax = Startup.BlazorMaximumReceiveMessageSize;
    var otherDataSize = 500; // Estimated overhead for other SignalR message data
    decimal waste = 1.35m; // Base64 re-encoding overhead factor (approximately 35%)
    long maxPSBTSize = (long)((blazorMax - otherDataSize) / waste);
}

@section Navbar {
	<partial name="_BackAndReturn" model="Model" />
}

<header class="text-center">
    <h1>@ViewData["Title"]</h1>
    <p class="lead text-secondary mt-3" text-translate="true">Using BTCPay Server Vault</p>
</header>

<partial name="_StatusMessage" />

@if (maxPSBTSize >= Model.SigningContext.PSBT.Length)
{
    <div class="row mt-5 mb-4">
        <div class="col-md-8 mx-auto">
            <component type="typeof(VaultBridgeUI)"
                       param-Controller="@(new SignHWIController()
                                         {
                                             StoreId = WalletId.Parse(walletId).StoreId,
                                             CryptoCode = WalletId.Parse(walletId).CryptoCode,
                                             PSBT = Convert.FromBase64String(Model.SigningContext.PSBT)
                                         })"
                       render-mode="Server" />
        </div>
    </div>
}
else
{
    <div class="alert alert-danger my-4" role="alert">
        <span>@StringLocalizer["PSBT too large to be signed by Vault. (Max: {0} bytes)", maxPSBTSize]</span>
    </div>
}

<div id="body" class="my-4">
    <form id="broadcastForm" asp-action="WalletSendVault" asp-route-walletId="@walletId" method="post" style="display:none;">
        <input type="hidden" id="WalletId" asp-for="WalletId" />
        <input type="hidden" asp-for="ReturnUrl" />
        <input type="hidden" asp-for="BackUrl" />
        <partial name="SigningContext" for="SigningContext" />
    </form>
</div>


@section PageFootContent
{
    <script src="~/js/vaultbridge.js" asp-append-version="true"></script>
    <script>
        vault.setSignedPSBT = function (data)
        {
            $("#SigningContext_PSBT").val(data.psbt);
            $("#broadcastForm").submit();
        }
    </script>
}