Added a-frame-architecture usiung wolverine sample.

wolverine/a-frame-architecture/FinancialApi.Application/Commands/ApplyFeeCommand.cs

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+namespace FinancialApi.Application.Commands;
+
+public record ApplyFeeCommand(int AccountId, decimal Amount);

wolverine/a-frame-architecture/FinancialApi.Application/Commands/ReverseJournalCommand.cs

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+namespace FinancialApi.Application.Commands;
+
+public record ReverseJournalCommand(Guid OriginalJournalId, string Reason);

wolverine/a-frame-architecture/FinancialApi.Application/Commands/TransferFundsCommand.cs

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+namespace FinancialApi.Application.Commands;
+
+public record TransferFundsCommand(int SourceAccountId, int DestinationAccountId, decimal Amount);

wolverine/a-frame-architecture/FinancialApi.Application/FinancialApi.Application.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net10.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\FinancialApi.Domain\FinancialApi.Domain.csproj"/>
+    </ItemGroup>
+
+    <ItemGroup>
+        <Reference Include="Microsoft.Extensions.Logging.Abstractions">
+            <HintPath>..\..\..\..\..\..\.nuget\packages\microsoft.extensions.logging.abstractions\10.0.9\lib\net10.0\Microsoft.Extensions.Logging.Abstractions.dll</HintPath>
+        </Reference>
+        <Reference Include="Wolverine">
+            <HintPath>..\..\..\..\..\..\.nuget\packages\wolverinefx\6.18.0\lib\net10.0\Wolverine.dll</HintPath>
+        </Reference>
+    </ItemGroup>
+
+</Project>

wolverine/a-frame-architecture/FinancialApi.Application/Handlers/ApplyFeeHandler.cs

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+using FinancialApi.Application.Commands;
+using FinancialApi.Application.Interfaces;
+using FinancialApi.Application.Models;
+using FinancialApi.Domain.Aggregates;
+using FinancialApi.Domain.Entities;
+using FinancialApi.Domain.Events;
+using Wolverine.Persistence;
+
+namespace FinancialApi.Application.Handlers;
+
+public static class ApplyFeeHandler
+{
+    public static async Task<FeeContext> LoadAsync(ApplyFeeCommand cmd, IAccountQuery query, TimeProvider timeProvider)
+    {
+        var source = await query.FindByIdAsync(cmd.AccountId);
+        var dest = await query.FindByIdAsync(99999);
+        if (source == null || dest == null)
+        {
+            throw new InvalidOperationException("Cannot process transfer. Account(s) not found.");
+        }
+
+        return new FeeContext(source, dest, timeProvider.GetUtcNow());
+    }
+
+    public static ( IStorageAction<Account> CustomerWrite, IStorageAction<Account> RevenueWrite,
+        IStorageAction<BalancedJournalEntry> JournalWrite, FeeAppliedEvent Event ) Handle(
+            ApplyFeeCommand cmd,
+            FeeContext context
+        )
+    {
+        var updatedSource = context.Source.ApplyPosting(cmd.Amount, EntryType.Debit);
+        var updatedRevenue = context.Destination.ApplyPosting(cmd.Amount, EntryType.Credit);
+
+        var lines = new List<JournalLine>
+        {
+            new(updatedSource.Id, cmd.Amount, EntryType.Debit), new(updatedRevenue.Id, cmd.Amount, EntryType.Credit)
+        };
+
+        var journalEntry = BalancedJournal.Create(
+            Guid.NewGuid(),
+            $"Service Fee Applied: {cmd.Amount} to Account {cmd.AccountId}",
+            context.TimeStamp,
+            lines
+        );
+
+        var @event = new FeeAppliedEvent(cmd.AccountId, cmd.Amount);
+
+        return (Storage.Update(updatedSource), Storage.Update(updatedRevenue), Storage.Insert(journalEntry.Entry),
+            @event);
+    }
+}

wolverine/a-frame-architecture/FinancialApi.Application/Handlers/FinancialEventHandler.cs

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+using FinancialApi.Domain.Events;
+using Microsoft.Extensions.Logging;
+
+namespace FinancialApi.Application.Handlers;
+
+public static class FinancialEventHandler
+{
+    public static void Handle(FeeAppliedEvent @event, IEventTracker store, ILogger logger)
+    {
+        var message = $"FeeApplied: ${@event.Amount} moved from Account {@event.AccountId} to Account 99999.";
+        logger.LogInformation("BACKGROUND EVENT FIRED: {Message}", message);
+        store.Add(message);
+    }
+
+    public static void Handle(FundsTransferredEvent @event, IEventTracker store, ILogger logger)
+    {
+        var message =
+            $"FundsTransferred: ${@event.Amount} moved from Account {@event.SourceAccountId} to Account {@event.DestinationAccountId}.";
+        logger.LogInformation("BACKGROUND EVENT FIRED: {Message}", message);
+        store.Add(message);
+    }
+
+    public static void Handle(JournalReversedEvent @event, IEventTracker store, ILogger logger)
+    {
+        var message =
+            $"JournalReversed: Original Entry {@event.OriginalJournalId} was reversed by Entry {@event.ReversalJournalId}.";
+        logger.LogInformation("BACKGROUND EVENT FIRED: {Message}", message);
+        store.Add(message);
+    }
+}

wolverine/a-frame-architecture/FinancialApi.Application/Handlers/ReverseJournalHandler.cs

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+using FinancialApi.Application.Commands;
+using FinancialApi.Application.Interfaces;
+using FinancialApi.Application.Models;
+using FinancialApi.Domain.Aggregates;
+using FinancialApi.Domain.Entities;
+using FinancialApi.Domain.Events;
+using Wolverine.Persistence;
+
+namespace FinancialApi.Application.Handlers;
+
+public static class ReverseJournalHandler
+{
+    public static async Task<JournalReversalContext?> LoadAsync(
+        ReverseJournalCommand cmd,
+        IReversalQuery query,
+        TimeProvider timeProvider
+    )
+    {
+        var (journalEnty, accounts) = await query.GetReversalDataAsync(cmd.OriginalJournalId);
+        if (journalEnty == null)
+        {
+            throw new InvalidOperationException("Journal not found");
+        }
+
+        if (accounts == null)
+        {
+            throw new InvalidOperationException("Journal accounts not found");
+        }
+
+        return new JournalReversalContext(journalEnty, accounts, timeProvider.GetUtcNow()) ??
+               throw new InvalidOperationException($"Journal Entry {cmd.OriginalJournalId} does not exist");
+    }
+
+    public static (IStorageAction<BalancedJournalEntry> JournalWrite, UnitOfWork<Account> AccountWrites, JournalReversedEvent
+        Event) Handle(ReverseJournalCommand cmd, JournalReversalContext context)
+    {
+        var reversalJournal = BalancedJournal.CreateReversal(
+            context.OriginalBalancedJournalEntry,
+            $"Reversal: {cmd.Reason}",
+            context.TimeStamp
+        );
+        var accountState = context.AffectedAccounts.ToDictionary(a => a.Id);
+
+        reversalJournal.Entry.Lines.ForEach(l =>
+            {
+                var currentAccount = accountState[l.AccountId];
+                accountState[l.AccountId] = currentAccount.ApplyPosting(l.Amount, l.Type);
+            }
+        );
+        var accountUow = new UnitOfWork<Account>();
+        foreach (var account in accountState.Values)
+        {
+            accountUow.Update(account);
+        }
+
+        return (Storage.Insert(reversalJournal.Entry), accountUow,
+            new JournalReversedEvent(cmd.OriginalJournalId, reversalJournal.Entry.Id));
+    }
+}

wolverine/a-frame-architecture/FinancialApi.Application/Handlers/TransferFundsHandler.cs

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+using FinancialApi.Application.Commands;
+using FinancialApi.Application.Interfaces;
+using FinancialApi.Application.Models;
+using FinancialApi.Domain.Aggregates;
+using FinancialApi.Domain.Entities;
+using FinancialApi.Domain.Events;
+using Wolverine.Persistence;
+
+namespace FinancialApi.Application.Handlers;
+
+public static class TransferFundsHandler
+{
+    public static async Task<TransferContext?> LoadAsync(
+        TransferFundsCommand cmd,
+        IAccountQuery query,
+        TimeProvider timeProvider
+    )
+    {
+        var source = await query.FindByIdAsync(cmd.SourceAccountId);
+        var dest = await query.FindByIdAsync(cmd.DestinationAccountId);
+
+        if (source == null || dest == null)
+        {
+            return null;
+        }
+
+        return new TransferContext(source, dest, timeProvider.GetUtcNow());
+    }
+
+    public static (IStorageAction<Account> SourceWrite, IStorageAction<Account> DestWrite, IStorageAction<BalancedJournalEntry>
+        JournalWrite, FundsTransferredEvent Event) Handle(TransferFundsCommand cmd, TransferContext context)
+    {
+        var updatedSource = context.Source.ApplyPosting(cmd.Amount, EntryType.Debit);
+        var updatedDest = context.Destination.ApplyPosting(cmd.Amount, EntryType.Credit);
+
+        var lines = new List<JournalLine>
+        {
+            new(context.Source.Id, cmd.Amount, EntryType.Debit),
+            new(context.Destination.Id, cmd.Amount, EntryType.Credit)
+        };
+
+        var journalEntry = BalancedJournal.Create(
+            Guid.NewGuid(),
+            $"Transfer: {cmd.Amount} from {cmd.SourceAccountId} to {cmd.DestinationAccountId}",
+            context.TimeStamp,
+            lines
+        );
+
+        var @event = new FundsTransferredEvent(cmd.SourceAccountId, cmd.DestinationAccountId, cmd.Amount);
+
+        return (Storage.Update(updatedSource), Storage.Update(updatedDest), Storage.Insert(journalEntry.Entry), @event);
+    }
+}

wolverine/a-frame-architecture/FinancialApi.Application/Interfaces/IAccountQuery.cs

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+using FinancialApi.Domain.Entities;
+
+namespace FinancialApi.Application.Interfaces;
+
+public interface IAccountQuery
+{
+    Task<Account?> FindByIdAsync(int id);
+}

wolverine/a-frame-architecture/FinancialApi.Application/Interfaces/IReversalQuery.cs

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+using FinancialApi.Domain.Entities;
+
+namespace FinancialApi.Application.Interfaces;
+
+public interface IReversalQuery
+{
+    Task<(BalancedJournalEntry?, List<Account>?)> GetReversalDataAsync(Guid journalEntryId);
+}

wolverine/a-frame-architecture/FinancialApi.Application/Models/FeeContext.cs

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+using FinancialApi.Domain.Entities;
+
+namespace FinancialApi.Application.Models;
+
+public record FeeContext(Account Source, Account Destination, DateTimeOffset TimeStamp);

wolverine/a-frame-architecture/FinancialApi.Application/Models/JournalReversalContext.cs

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+using FinancialApi.Domain.Entities;
+
+namespace FinancialApi.Application.Models;
+
+public record JournalReversalContext(
+    BalancedJournalEntry OriginalBalancedJournalEntry,
+    IReadOnlyList<Account> AffectedAccounts,
+    DateTimeOffset TimeStamp
+);

wolverine/a-frame-architecture/FinancialApi.Application/Models/TransferContext.cs

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+using FinancialApi.Domain.Entities;
+
+namespace FinancialApi.Application.Models;
+
+public record TransferContext(Account Source, Account Destination, DateTimeOffset TimeStamp);