From e331030bb0039b39478fa188edf59b478161883e Mon Sep 17 00:00:00 2001
From: Stevan Freeborn <65925598+StevanFreeborn@users.noreply.github.com>
Date: Sat, 14 Feb 2026 05:53:41 -0600
Subject: [PATCH] feat(core): add balance model

---
 src/FiscalOS.Core/Accounts/Account.cs | 10 ++++++++++
 src/FiscalOS.Core/Accounts/Balance.cs | 21 +++++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 src/FiscalOS.Core/Accounts/Balance.cs

diff --git a/src/FiscalOS.Core/Accounts/Account.cs b/src/FiscalOS.Core/Accounts/Account.cs
index 3434ba6..4193a45 100644
--- a/src/FiscalOS.Core/Accounts/Account.cs
+++ b/src/FiscalOS.Core/Accounts/Account.cs
@@ -8,6 +8,9 @@ public sealed class Account : Entity
   public string Name { get; init; } = string.Empty;
   public AccountMetadata? Metadata { get; init; }
 
+  private readonly List<Balance> _balances = [];
+  public IEnumerable<Balance> Balances => _balances;
+
   public static Account From(Guid institutionId, string name, AccountMetadata accountMetadata)
   {
     return new()
@@ -17,4 +20,11 @@ public sealed class Account : Entity
       Metadata = accountMetadata,
     };
   }
+
+  public void AddBalance(Balance balance)
+  {
+    ArgumentNullException.ThrowIfNull(balance);
+
+    _balances.Add(balance);
+  }
 }
\ No newline at end of file
diff --git a/src/FiscalOS.Core/Accounts/Balance.cs b/src/FiscalOS.Core/Accounts/Balance.cs
new file mode 100644
index 0000000..b2a36b4
--- /dev/null
+++ b/src/FiscalOS.Core/Accounts/Balance.cs
@@ -0,0 +1,21 @@
+namespace FiscalOS.Core.Accounts;
+
+public sealed class Balance : Entity
+{
+  public Guid AccountId { get; init; }
+  public decimal Current { get; init; }
+  public decimal Available { get; init; }
+
+  private Balance()
+  {
+  }
+
+  public static Balance From(decimal current, decimal available)
+  {
+    return new()
+    {
+      Current = current,
+      Available = available,
+    };
+  }
+}
\ No newline at end of file