feat(api): implement storing connected insitution in db

src/Directory.Packages.props

@@ -3,6 +3,7 @@
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
   </PropertyGroup>
   <ItemGroup>
+    <PackageVersion Include="Going.Plaid" Version="6.56.0" />
     <PackageVersion Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="10.0.2" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.Design" Version="10.0.2">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

src/FiscalOS.API/Accounts/AccountsExtensions.cs

@@ -0,0 +1,15 @@
+namespace FiscalOS.API.Accounts;
+
+internal static class AccountsExtensions
+{
+  private const string RouteGroupPrefix = "/accounts";
+
+  public static RouteGroupBuilder MapAccountsEndpoints(this WebApplication app)
+  {
+    var accountsGroup = app.MapGroup(RouteGroupPrefix).RequireAuthorization();
+
+    accountsGroup.MapConnectEndpoint();
+
+    return accountsGroup;
+  }
+}

src/FiscalOS.API/Accounts/Connect/Endpoint.cs

@@ -0,0 +1,67 @@
+using FiscalOS.Core.Accounts;
+
+namespace FiscalOS.API.Accounts.Connect;
+
+internal static class Endpoint
+{
+  private const string Route = "/connect";
+
+  public static RouteHandlerBuilder MapConnectEndpoint(this RouteGroupBuilder groupBuilder)
+  {
+    return groupBuilder.MapPost(Route, HandleAsync);
+  }
+
+  private static async Task<IResult> HandleAsync(
+    HttpContext httpContext,
+    [FromBody] Request request,
+    [FromServices] AppDbContext appDbContext,
+    [FromServices] PlaidService plaidService,
+    [FromServices] IEncryptor encryptor,
+    CancellationToken ct
+  )
+  {
+    var userId = httpContext.GetUserId();
+
+    var user = await appDbContext.Users
+      .Include(u => u.Institutions
+        .Where(
+          i => i.Metadata is PlaidMetadata &&
+            ((PlaidMetadata)i.Metadata).PlaidId == request.PlaidInstitutionId
+        )
+      )
+      .ThenInclude(i => i.Metadata)
+      .SingleOrDefaultAsync(u => u.Id == userId, ct);
+
+    if (user is null)
+    {
+      return Results.Problem(
+        statusCode: StatusCodes.Status401Unauthorized,
+        title: "Unauthorized",
+        detail: "You are not authorized to connect an institution. Please log in and try again."
+      );
+    }
+
+    if (user.Institutions.Any())
+    {
+      return Results.Problem(
+        statusCode: StatusCodes.Status409Conflict,
+        title: "Institution already connected",
+        detail: "The user has already connected an institution with the provided Plaid Institution Id."
+      );
+    }
+
+    var (itemId, accessToken) = await plaidService.ExchangeTokenAsync(request.PublicToken);
+    var item = await plaidService.GetItemAsync(accessToken);
+
+    var encryptedAccessToken = await encryptor.EncryptAsyncFor(user, accessToken, ct);
+
+    var plaidMetadata = PlaidMetadata.From(item.InstitutionId, item.InstitutionName, encryptedAccessToken);
+    var institution = Institution.From(item.InstitutionName, plaidMetadata);
+
+    user.AddInstitution(institution);
+
+    await appDbContext.SaveChangesAsync(ct);
+
+    return Results.Ok();
+  }
+}

src/FiscalOS.API/Accounts/Connect/Request.cs

@@ -0,0 +1,22 @@
+namespace FiscalOS.API.Accounts.Connect;
+
+public record Request : IValidatableObject
+{
+  public string PublicToken { get; init; } = string.Empty;
+  public string PlaidInstitutionId { get; init; } = string.Empty;
+
+  public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
+  {
+    if (string.IsNullOrWhiteSpace(PublicToken))
+    {
+      var fieldName = nameof(PublicToken);
+      yield return new($"The {fieldName} field is required.", [fieldName]);
+    }
+
+    if (string.IsNullOrWhiteSpace(PlaidInstitutionId))
+    {
+      var fieldName = nameof(PlaidInstitutionId);
+      yield return new($"The {fieldName} field is required.", [fieldName]);
+    }
+  }
+}

src/FiscalOS.API/Login/Endpoint.cs

@@ -11,7 +11,7 @@ internal static class Endpoint
 
   private static async Task<IResult> HandleAsync(
     HttpContext httpContext,
-    [FromBody] LoginRequest loginRequest,
+    [FromBody] Request loginRequest,
     [FromServices] AppDbContext appDbContext,
     [FromServices] IPasswordHasher passwordHasher,
     [FromServices] ITokenGenerator tokenService

src/FiscalOS.API/Login/Request.cs

@@ -1,7 +1,6 @@
-
 namespace FiscalOS.API.Login;
 
-public record LoginRequest : IValidatableObject
+public record Request : IValidatableObject
 {
   public string Username { get; init; } = string.Empty;
   public string Password { get; init; } = string.Empty;
@@ -10,12 +9,14 @@ public record LoginRequest : IValidatableObject
   {
     if (string.IsNullOrWhiteSpace(Username))
     {
-      yield return new("The Username field is required.", [nameof(Username)]);
+      var fieldName = nameof(Username);
+      yield return new($"The {fieldName} field is required.", [fieldName]);
     }
 
     if (string.IsNullOrWhiteSpace(Password))
     {
-      yield return new("The Password field is required.", [nameof(Password)]);
+      var fieldName = nameof(Password);
+      yield return new($"The {fieldName} field is required.", [fieldName]);
     }
   }
 }

src/FiscalOS.API/Program.cs

@@ -37,4 +37,6 @@ app.MapLoginEndpoint();
 app.MapRefreshEndpoint()
   .RequireAuthorization(Schemes.AllowExpiredTokens);
 
+app.MapAccountsEndpoints();
+
 app.Run();

src/FiscalOS.API/Usings.cs

@@ -2,10 +2,14 @@ global using System.ComponentModel.DataAnnotations;
 global using System.Security.Claims;
 global using System.Text.Json.Serialization;
 
+global using FiscalOS.API.Accounts;
+global using FiscalOS.API.Accounts.Connect;
 global using FiscalOS.API.Http;
 global using FiscalOS.API.Login;
 global using FiscalOS.API.Refresh;
 global using FiscalOS.Core.Authentication;
+global using FiscalOS.Core.Security;
+global using FiscalOS.Infra.Accounts.Plaid;
 global using FiscalOS.Infra.Authentication;
 global using FiscalOS.Infra.Data;
 global using FiscalOS.Infra.DependencyInjection;

src/FiscalOS.API/appsettings.Example.json

@@ -19,7 +19,7 @@
     "KeysDirectoryPath": "KeysDirectoryPath",
     "PrimaryKeyId": "PrimaryKeyId"
   },
-  "PlaidOptions": {
+  "PlaidClientOptions": {
     "ClientId": "ClientId",
     "Secret": "Secret"
   }

src/FiscalOS.Core/Accounts/Institution.cs

@@ -0,0 +1,24 @@
+namespace FiscalOS.Core.Accounts;
+
+public sealed class Institution : Entity
+{
+  public Guid UserId { get; init; }
+  public string Name { get; init; } = string.Empty;
+  public InstitutionMetadata Metadata { get; init; } = null!;
+
+  private Institution()
+  {
+  }
+
+  public static Institution From(string? name, InstitutionMetadata metadata)
+  {
+    ArgumentNullException.ThrowIfNull(name, nameof(name));
+    ArgumentNullException.ThrowIfNull(metadata, nameof(metadata));
+
+    return new Institution()
+    {
+      Name = name,
+      Metadata = metadata
+    };
+  }
+}

src/FiscalOS.Core/Accounts/InstitutionMetadata.cs

@@ -0,0 +1,15 @@
+namespace FiscalOS.Core.Accounts;
+
+public abstract class InstitutionMetadata : Entity
+{
+  private readonly string _type;
+
+  public string Type => _type;
+
+  public Guid InstitutionId { get; init; }
+
+  protected InstitutionMetadata(string type)
+  {
+    _type = type;
+  }
+}

src/FiscalOS.Core/Identity/RefreshToken.cs

@@ -24,7 +24,7 @@ public sealed class RefreshToken : Entity
 
   public static RefreshToken From(User user, string token, DateTimeOffset expiresAt)
   {
-    ArgumentNullException.ThrowIfNull(user);
+    ArgumentNullException.ThrowIfNull(user, nameof(user));
 
     return new()
     {

src/FiscalOS.Core/Identity/User.cs

@@ -2,15 +2,17 @@ namespace FiscalOS.Core.Identity;
 
 public sealed class User : Entity
 {
-  private readonly List<RefreshToken> _refreshTokens = [];
-
   public string Username { get; init; } = string.Empty;
   public string HashedPassword { get; init; } = string.Empty;
   public string EncryptionKeyId { get; init; } = string.Empty;
   public string EncryptedDataKey { get; init; } = string.Empty;
 
+  private readonly List<RefreshToken> _refreshTokens = [];
   public IEnumerable<RefreshToken> RefreshTokens => _refreshTokens;
 
+  private readonly List<Institution> _institutions = [];
+  public IEnumerable<Institution> Institutions => _institutions;
+
   private User()
   {
   }
@@ -22,9 +24,9 @@ public sealed class User : Entity
 
   public static User From(string username, string hashedPassword, EncryptedDataKey encryptedDataKey)
   {
-    ArgumentNullException.ThrowIfNull(username);
-    ArgumentNullException.ThrowIfNull(hashedPassword);
-    ArgumentNullException.ThrowIfNull(encryptedDataKey);
+    ArgumentNullException.ThrowIfNull(username, nameof(username));
+    ArgumentNullException.ThrowIfNull(hashedPassword, nameof(hashedPassword));
+    ArgumentNullException.ThrowIfNull(encryptedDataKey, nameof(encryptedDataKey));
 
     return new()
     {
@@ -37,8 +39,15 @@ public sealed class User : Entity
 
   public void AddRefreshToken(RefreshToken refreshToken)
   {
-    ArgumentNullException.ThrowIfNull(refreshToken);
+    ArgumentNullException.ThrowIfNull(refreshToken, nameof(refreshToken));
 
     _refreshTokens.Add(refreshToken);
   }
+
+  public void AddInstitution(Institution institution)
+  {
+    ArgumentNullException.ThrowIfNull(institution, nameof(institution));
+
+    _institutions.Add(institution);
+  }
 }

src/FiscalOS.Core/Security/EncryptedDataKey.cs

@@ -13,8 +13,8 @@ public sealed record EncryptedDataKey
 
   public static EncryptedDataKey From(string keyIdUsed, string encryptedKey)
   {
-    ArgumentNullException.ThrowIfNull(keyIdUsed);
-    ArgumentNullException.ThrowIfNull(encryptedKey);
+    ArgumentNullException.ThrowIfNull(keyIdUsed, nameof(keyIdUsed));
+    ArgumentNullException.ThrowIfNull(encryptedKey, nameof(encryptedKey));
 
     return new(keyIdUsed, encryptedKey);
   }

src/FiscalOS.Core/Security/KeyRingEntry.cs

@@ -13,8 +13,8 @@ public sealed record KeyRingEntry
 
   public static KeyRingEntry From(string keyId, string key)
   {
-    ArgumentNullException.ThrowIfNull(keyId);
-    ArgumentNullException.ThrowIfNull(key);
+    ArgumentNullException.ThrowIfNull(keyId, nameof(keyId));
+    ArgumentNullException.ThrowIfNull(key, nameof(key));
 
     return new(keyId, key);
   }

src/FiscalOS.Core/Usings.cs

@@ -1,3 +1,4 @@
+global using FiscalOS.Core.Accounts;
 global using FiscalOS.Core.Data;
 global using FiscalOS.Core.Identity;
 global using FiscalOS.Core.Security;

src/FiscalOS.Infra/Accounts/Plaid/PlaidClientOptions.cs

@@ -0,0 +1,32 @@
+namespace FiscalOS.Infra.Accounts.Plaid;
+
+public sealed record PlaidClientOptions
+{
+  public string ClientId { get; init; } = string.Empty;
+  public string Secret { get; init; } = string.Empty;
+
+  public IOptions<PlaidOptions> ToPlaidOptions()
+  {
+    return Options.Create<PlaidOptions>(new()
+    {
+      ClientId = ClientId,
+      Secret = Secret
+    });
+  }
+}
+
+public sealed record PlaidClientOptionsSetup : IConfigureOptions<PlaidClientOptions>
+{
+  private const string SectionName = nameof(PlaidClientOptions);
+  private readonly IConfiguration _configuration;
+
+  public PlaidClientOptionsSetup(IConfiguration configuration)
+  {
+    _configuration = configuration;
+  }
+
+  public void Configure(PlaidClientOptions options)
+  {
+    _configuration.GetSection(SectionName).Bind(options);
+  }
+}

src/FiscalOS.Infra/Accounts/Plaid/PlaidException.cs

@@ -0,0 +1,16 @@
+namespace FiscalOS.Infra.Accounts.Plaid;
+
+public class PlaidException : Exception
+{
+  public PlaidException()
+  {
+  }
+
+  public PlaidException(string message) : base(message)
+  {
+  }
+
+  public PlaidException(string message, Exception innerException) : base(message, innerException)
+  {
+  }
+}

src/FiscalOS.Infra/Accounts/Plaid/PlaidMetadata.cs

@@ -0,0 +1,31 @@
+namespace FiscalOS.Infra.Accounts.Plaid;
+
+public sealed class PlaidMetadata : InstitutionMetadata
+{
+  public const string TypeValue = "Plaid";
+  public string PlaidId { get; init; } = string.Empty;
+  public string PlaidName { get; init; } = string.Empty;
+  public string EncryptedAccessToken { get; init; } = string.Empty;
+
+  private PlaidMetadata() : base(TypeValue)
+  {
+  }
+
+  public static PlaidMetadata From(
+    string? plaidId,
+    string? plaidName,
+    string encryptedAccessToken
+  )
+  {
+    ArgumentNullException.ThrowIfNull(plaidId, nameof(plaidId));
+    ArgumentNullException.ThrowIfNull(plaidName, nameof(plaidName));
+    ArgumentNullException.ThrowIfNull(encryptedAccessToken, nameof(encryptedAccessToken));
+
+    return new PlaidMetadata
+    {
+      PlaidId = plaidId,
+      PlaidName = plaidName,
+      EncryptedAccessToken = encryptedAccessToken
+    };
+  }
+}

src/FiscalOS.Infra/Accounts/Plaid/PlaidService.cs

@@ -0,0 +1,47 @@
+namespace FiscalOS.Infra.Accounts.Plaid;
+
+public sealed class PlaidService
+{
+  private readonly PlaidClient _client;
+
+  private PlaidService(PlaidClient client)
+  {
+    _client = client;
+  }
+
+  public static PlaidService From(IServiceProvider sp)
+  {
+    var client = sp.GetRequiredService<PlaidClient>();
+    return new(client);
+  }
+
+  public async Task<(string ItemId, string AccessToken)> ExchangeTokenAsync(string publicToken)
+  {
+    var ptr = await _client.ItemPublicTokenExchangeAsync(new()
+    {
+      PublicToken = publicToken,
+    }).ConfigureAwait(false);
+
+    if (ptr.IsSuccessStatusCode is false)
+    {
+      throw new PlaidException("Unable to exchange public token for access token");
+    }
+
+    return (ptr.ItemId, ptr.AccessToken);
+  }
+
+  public async Task<ItemWithConsentFields> GetItemAsync(string accessToken)
+  {
+    var ar = await _client.ItemGetAsync(new()
+    {
+      AccessToken = accessToken,
+    }).ConfigureAwait(false);
+
+    if (ar.IsSuccessStatusCode is false)
+    {
+      throw new PlaidException("Unable to retrieve item");
+    }
+
+    return ar.Item;
+  }
+}

src/FiscalOS.Infra/Data/AppDbContext.cs

@@ -1,3 +1,5 @@
+using Institution = FiscalOS.Core.Accounts.Institution;
+
 namespace FiscalOS.Infra.Data;
 
 public sealed class AppDbContext(
@@ -49,15 +51,20 @@ public sealed class AppDbContext(
 
     modelBuilder.Entity<User>(static eb =>
     {
+      eb.Property(static u => u.Username);
+      eb.HasIndex(static u => u.Username).IsUnique();
+
+      eb.Property(static u => u.HashedPassword);
+
       eb.HasMany(static u => u.RefreshTokens)
         .WithOne(static t => t.User)
         .HasForeignKey(static t => t.UserId)
         .OnDelete(DeleteBehavior.Cascade);
 
-      eb.Property(static u => u.Username);
-      eb.HasIndex(static u => u.Username).IsUnique();
-
-      eb.Property(static u => u.HashedPassword);
+      eb.HasMany(static u => u.Institutions)
+        .WithOne()
+        .HasForeignKey(static i => i.UserId)
+        .OnDelete(DeleteBehavior.Cascade);
     });
 
     modelBuilder.Entity<RefreshToken>(static eb =>
@@ -69,5 +76,33 @@ public sealed class AppDbContext(
       eb.Property(static t => t.Token);
       eb.HasIndex(static t => t.Token).IsUnique();
     });
+
+    modelBuilder.Entity<Institution>(static eb =>
+    {
+      eb.Property(static i => i.Name);
+
+      eb.HasOne(static i => i.Metadata)
+        .WithOne()
+        .HasForeignKey<InstitutionMetadata>(static m => m.InstitutionId)
+        .OnDelete(DeleteBehavior.Cascade);
+    });
+
+    modelBuilder.Entity<InstitutionMetadata>(static eb =>
+    {
+      eb.HasDiscriminator(static m => m.Type)
+        .HasValue<PlaidMetadata>(PlaidMetadata.TypeValue);
+
+      eb.Property(static m => m.InstitutionId);
+      eb.Property(static m => m.Type);
+    });
+
+    modelBuilder.Entity<PlaidMetadata>(static eb =>
+    {
+      eb.HasBaseType<InstitutionMetadata>();
+
+      eb.Property(static m => m.PlaidId);
+      eb.Property(static m => m.PlaidName);
+      eb.Property(static m => m.EncryptedAccessToken);
+    });
   }
 }

src/FiscalOS.Infra/DependencyInjection/ServiceCollectionExtensions.cs

@@ -6,6 +6,7 @@ public static class ServiceCollectionExtensions
   {
     services.AddSingleton<IAuthorizationMiddlewareResultHandler, ProblemDetailsAuthResultHandler>();
     
+    services.AddHttpClient();
     services.AddSingleton(TimeProvider.System);
     services.AddSingleton<IFileSystem, FileSystem>();
 
@@ -23,6 +24,17 @@ public static class ServiceCollectionExtensions
     services.AddDbContext<AppDbContext>();
     services.AddHostedService<MigrationService>();
 
+    services.ConfigureOptions<PlaidClientOptionsSetup>();
+    services.AddSingleton(static sp =>
+    {
+      var factory = sp.GetRequiredService<IHttpClientFactory>();
+      var logger = sp.GetRequiredService<ILogger<PlaidClient>>();
+      var clientOptions = sp.GetRequiredService<IOptions<PlaidClientOptions>>();
+      var options = clientOptions.Value.ToPlaidOptions();
+      return new PlaidClient(options, factory, logger);
+    });
+    services.AddSingleton(PlaidService.From);
+
     return services;
   }
 }

src/FiscalOS.Infra/FiscalOS.Infra.csproj

@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <ItemGroup>
+    <PackageReference Include="Going.Plaid" />
     <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" />
     <PackageReference Include="Microsoft.Extensions.Hosting" />

src/FiscalOS.Infra/Migrations/20260212215015_InstitutionAndMetadata.Designer.cs

@@ -0,0 +1,215 @@
+// <auto-generated />
+using System;
+using FiscalOS.Infra.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace FiscalOS.Infra.Migrations
+{
+    [DbContext(typeof(AppDbContext))]
+    [Migration("20260212215015_InstitutionAndMetadata")]
+    partial class InstitutionAndMetadata
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "10.0.2");
+
+            modelBuilder.Entity("FiscalOS.Core.Accounts.Institution", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("UpdatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("Institution");
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Accounts.InstitutionMetadata", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid>("InstitutionId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Type")
+                        .IsRequired()
+                        .HasMaxLength(21)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("UpdatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("InstitutionId")
+                        .IsUnique();
+
+                    b.ToTable("InstitutionMetadata");
+
+                    b.HasDiscriminator<string>("Type").HasValue("InstitutionMetadata");
+
+                    b.UseTphMappingStrategy();
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Identity.RefreshToken", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("ExpiresAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("Revoked")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Token")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("UpdatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Token")
+                        .IsUnique();
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("RefreshTokens");
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Identity.User", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("EncryptedDataKey")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("EncryptionKeyId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("HashedPassword")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("UpdatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Username")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Username")
+                        .IsUnique();
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("FiscalOS.Infra.Accounts.Plaid.PlaidMetadata", b =>
+                {
+                    b.HasBaseType("FiscalOS.Core.Accounts.InstitutionMetadata");
+
+                    b.Property<string>("EncryptedAccessToken")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PlaidId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PlaidName")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasDiscriminator().HasValue("Plaid");
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Accounts.Institution", b =>
+                {
+                    b.HasOne("FiscalOS.Core.Identity.User", null)
+                        .WithMany("Institutions")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Accounts.InstitutionMetadata", b =>
+                {
+                    b.HasOne("FiscalOS.Core.Accounts.Institution", null)
+                        .WithOne("Metadata")
+                        .HasForeignKey("FiscalOS.Core.Accounts.InstitutionMetadata", "InstitutionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Identity.RefreshToken", b =>
+                {
+                    b.HasOne("FiscalOS.Core.Identity.User", "User")
+                        .WithMany("RefreshTokens")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Accounts.Institution", b =>
+                {
+                    b.Navigation("Metadata")
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Identity.User", b =>
+                {
+                    b.Navigation("Institutions");
+
+                    b.Navigation("RefreshTokens");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

src/FiscalOS.Infra/Migrations/20260212215015_InstitutionAndMetadata.cs

@@ -0,0 +1,81 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace FiscalOS.Infra.Migrations
+{
+    /// <inheritdoc />
+    public partial class InstitutionAndMetadata : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "Institution",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "TEXT", nullable: false),
+                    UserId = table.Column<Guid>(type: "TEXT", nullable: false),
+                    Name = table.Column<string>(type: "TEXT", nullable: false),
+                    CreatedAt = table.Column<DateTimeOffset>(type: "TEXT", nullable: false),
+                    UpdatedAt = table.Column<DateTimeOffset>(type: "TEXT", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Institution", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_Institution_Users_UserId",
+                        column: x => x.UserId,
+                        principalTable: "Users",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "InstitutionMetadata",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "TEXT", nullable: false),
+                    Type = table.Column<string>(type: "TEXT", maxLength: 21, nullable: false),
+                    InstitutionId = table.Column<Guid>(type: "TEXT", nullable: false),
+                    PlaidId = table.Column<string>(type: "TEXT", nullable: true),
+                    PlaidName = table.Column<string>(type: "TEXT", nullable: true),
+                    EncryptedAccessToken = table.Column<string>(type: "TEXT", nullable: true),
+                    CreatedAt = table.Column<DateTimeOffset>(type: "TEXT", nullable: false),
+                    UpdatedAt = table.Column<DateTimeOffset>(type: "TEXT", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_InstitutionMetadata", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_InstitutionMetadata_Institution_InstitutionId",
+                        column: x => x.InstitutionId,
+                        principalTable: "Institution",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Institution_UserId",
+                table: "Institution",
+                column: "UserId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_InstitutionMetadata_InstitutionId",
+                table: "InstitutionMetadata",
+                column: "InstitutionId",
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "InstitutionMetadata");
+
+            migrationBuilder.DropTable(
+                name: "Institution");
+        }
+    }
+}

src/FiscalOS.Infra/Migrations/AppDbContextModelSnapshot.cs

@@ -17,6 +17,64 @@ namespace FiscalOS.Infra.Migrations
 #pragma warning disable 612, 618
             modelBuilder.HasAnnotation("ProductVersion", "10.0.2");
 
+            modelBuilder.Entity("FiscalOS.Core.Accounts.Institution", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("UpdatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid>("UserId")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("UserId");
+
+                    b.ToTable("Institution");
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Accounts.InstitutionMetadata", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("CreatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<Guid>("InstitutionId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Type")
+                        .IsRequired()
+                        .HasMaxLength(21)
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTimeOffset>("UpdatedAt")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("InstitutionId")
+                        .IsUnique();
+
+                    b.ToTable("InstitutionMetadata");
+
+                    b.HasDiscriminator<string>("Type").HasValue("InstitutionMetadata");
+
+                    b.UseTphMappingStrategy();
+                });
+
             modelBuilder.Entity("FiscalOS.Core.Identity.RefreshToken", b =>
                 {
                     b.Property<Guid>("Id")
@@ -88,6 +146,43 @@ namespace FiscalOS.Infra.Migrations
                     b.ToTable("Users");
                 });
 
+            modelBuilder.Entity("FiscalOS.Infra.Accounts.Plaid.PlaidMetadata", b =>
+                {
+                    b.HasBaseType("FiscalOS.Core.Accounts.InstitutionMetadata");
+
+                    b.Property<string>("EncryptedAccessToken")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PlaidId")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PlaidName")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasDiscriminator().HasValue("Plaid");
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Accounts.Institution", b =>
+                {
+                    b.HasOne("FiscalOS.Core.Identity.User", null)
+                        .WithMany("Institutions")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("FiscalOS.Core.Accounts.InstitutionMetadata", b =>
+                {
+                    b.HasOne("FiscalOS.Core.Accounts.Institution", null)
+                        .WithOne("Metadata")
+                        .HasForeignKey("FiscalOS.Core.Accounts.InstitutionMetadata", "InstitutionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
             modelBuilder.Entity("FiscalOS.Core.Identity.RefreshToken", b =>
                 {
                     b.HasOne("FiscalOS.Core.Identity.User", "User")
@@ -99,8 +194,16 @@ namespace FiscalOS.Infra.Migrations
                     b.Navigation("User");
                 });
 
+            modelBuilder.Entity("FiscalOS.Core.Accounts.Institution", b =>
+                {
+                    b.Navigation("Metadata")
+                        .IsRequired();
+                });
+
             modelBuilder.Entity("FiscalOS.Core.Identity.User", b =>
                 {
+                    b.Navigation("Institutions");
+
                     b.Navigation("RefreshTokens");
                 });
 #pragma warning restore 612, 618

src/FiscalOS.Infra/Usings.cs

@@ -5,15 +5,20 @@ global using System.Security.Cryptography;
 global using System.Text;
 global using System.Text.Json;
 
+global using FiscalOS.Core.Accounts;
 global using FiscalOS.Core.Authentication;
 global using FiscalOS.Core.Data;
 global using FiscalOS.Core.Identity;
 global using FiscalOS.Core.Security;
+global using FiscalOS.Infra.Accounts.Plaid;
 global using FiscalOS.Infra.Authentication;
 global using FiscalOS.Infra.Authorization;
 global using FiscalOS.Infra.Data;
 global using FiscalOS.Infra.Security;
 
+global using Going.Plaid;
+global using Going.Plaid.Entity;
+
 global using Microsoft.AspNetCore.Authentication.JwtBearer;
 global using Microsoft.AspNetCore.Authorization;
 global using Microsoft.AspNetCore.Authorization.Policy;

tests/FiscalOS.API.Tests/Assertions/HttpResponseMessageAssertions.cs

@@ -78,12 +78,6 @@ internal sealed class HttpResponseMessageAssertions(
 
   private async Task<T> ValidateAndDeserialize<T>(HttpStatusCode expectedStatusCode) where T : ProblemDetails
   {
-    _chain.ForCondition(Subject.Content.Headers.ContentType?.MediaType is "application/problem+json")
-      .FailWith(
-        "Expected response to be application/problem+json, but found {0}",
-        Subject.Content.Headers.ContentType?.MediaType
-      );
-
     _chain.ForCondition(Subject.StatusCode == expectedStatusCode)
       .FailWith(
         "Expected response status code to be {0}, but found {1}",
@@ -91,6 +85,12 @@ internal sealed class HttpResponseMessageAssertions(
         Subject.StatusCode
       );
 
+    _chain.ForCondition(Subject.Content.Headers.ContentType?.MediaType is "application/problem+json")
+      .FailWith(
+        "Expected response to be application/problem+json, but found {0}",
+        Subject.Content.Headers.ContentType?.MediaType
+      );
+
     var problem = await Subject.Content.ReadFromJsonAsync<T>();
 
     _chain.ForCondition(problem is not null)

tests/FiscalOS.API.Tests/Common/SerializableDictionary.cs

@@ -0,0 +1,41 @@
+namespace FiscalOS.API.Tests.Common;
+
+public interface ISerializableDictionary<TKey, TValue> : IDictionary<TKey, TValue>, IXunitSerializable
+{
+}
+
+public class SerializableDictionary<TKey, TValue> 
+  : Dictionary<TKey, TValue>, ISerializableDictionary<TKey, TValue> where TKey : notnull
+{
+  public SerializableDictionary() { }
+
+  public SerializableDictionary(IDictionary<TKey, TValue> dictionary) : base(dictionary)
+  {
+  }
+
+  public void Deserialize(IXunitSerializationInfo info)
+  {
+    Clear();
+
+    var keysJson = info.GetValue<string>("_DictKeys") ?? "[]";
+    var valuesJson = info.GetValue<string>("_DictValues") ?? "[]";
+    var keys = JsonSerializer.Deserialize<List<TKey>>(keysJson);
+    var values = JsonSerializer.Deserialize<List<TValue>>(valuesJson);
+
+    if (keys is null || values is null || keys.Count != values.Count)
+    {
+      return;
+    }
+
+    for (var i = 0; i < keys.Count; i++)
+    {
+      Add(keys[i], values[i]);
+    }
+  }
+
+  public void Serialize(IXunitSerializationInfo info)
+  {
+    info.AddValue("_DictKeys", JsonSerializer.Serialize(Keys));
+    info.AddValue("_DictValues", JsonSerializer.Serialize(Values));
+  }
+}

tests/FiscalOS.API.Tests/FiscalOS.API.Tests.csproj

@@ -15,6 +15,7 @@
 
   <ItemGroup>
     <Content Include="xunit.runner.json" CopyToOutputDirectory="PreserveNewest" />
+    <Content Include="appsettings.Test.json" CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
 
   <ItemGroup>

tests/FiscalOS.API.Tests/Infra/TestApi.cs

@@ -1,3 +1,5 @@
+using Microsoft.Extensions.Configuration;
+
 namespace FiscalOS.API.Tests.Infra;
 
 public class TestApi : WebApplicationFactory<Program>
@@ -8,6 +10,12 @@ public class TestApi : WebApplicationFactory<Program>
 
     builder.ConfigureLogging(static c => c.ClearProviders());
 
+    builder.ConfigureAppConfiguration(static c =>
+    {
+      var testConfigPath = Path.Combine(AppContext.BaseDirectory, "appsettings.Test.json");
+      c.AddJsonFile(testConfigPath, optional: false);
+    });
+
     builder.ConfigureTestServices(static c =>
     {
       c.AddSingleton(Options.Create(new AppDbContextOptions()

tests/FiscalOS.API.Tests/Integration/ConnectTests.cs

@@ -0,0 +1,217 @@
+using Institution = FiscalOS.Core.Accounts.Institution;
+
+namespace FiscalOS.API.Tests.Integration;
+
+public class ConnectTests(TestApi testApi) : IntegrationTest(testApi)
+{
+  private static readonly Uri ConnectUri = new("/accounts/connect", UriKind.Relative);
+
+  [Fact]
+  public async Task Connect_WhenCalledWithoutValidToken_ItShouldReturn401WithProblemDetails()
+  {
+    var res = await Client.PostAsJsonAsync(ConnectUri, new { }, TestContext.Current.CancellationToken);
+
+    await res.Should().BeProblemDetails(HttpStatusCode.Unauthorized);
+  }
+
+  [Fact]
+  public async Task Connect_WhenCalledWithoutPublicTokenOrPlaidInstitutionId_ItShouldReturn400WithProblemDetails()
+  {
+    var jwt = JwtTokenBuilder.New()
+      .WithClaim(JwtRegisteredClaimNames.Sub, Guid.NewGuid().ToString())
+      .Build();
+
+    using var content = new StringContent(JsonSerializer.Serialize(new { }), Encoding.UTF8, "application/json");
+    using var request = new HttpRequestMessage(HttpMethod.Post, ConnectUri)
+    {
+      Content = content,
+    };
+    request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", jwt);
+
+    var response = await Client.SendAsync(request, TestContext.Current.CancellationToken);
+
+    await response.Should().BeValidationProblemDetails(new Dictionary<string, string[]>()
+    {
+      ["PublicToken"] = ["The PublicToken field is required."],
+      ["PlaidInstitutionId"] = ["The PlaidInstitutionId field is required."],
+    });
+  }
+
+  [Fact]
+  public async Task Connect_WhenCalledWithoutPublicToken_ItShouldReturn400WithProblemDetails()
+  {
+    var jwt = JwtTokenBuilder.New()
+      .WithClaim(JwtRegisteredClaimNames.Sub, Guid.NewGuid().ToString())
+      .Build();
+
+    var json = JsonSerializer.Serialize(new { plaidInstitutionId = "id" });
+    using var content = new StringContent(json, Encoding.UTF8, "application/json");
+    using var request = new HttpRequestMessage(HttpMethod.Post, ConnectUri)
+    {
+      Content = content,
+    };
+    request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", jwt);
+
+    var response = await Client.SendAsync(request, TestContext.Current.CancellationToken);
+
+    await response.Should().BeValidationProblemDetails(new Dictionary<string, string[]>()
+    {
+      ["PublicToken"] = ["The PublicToken field is required."],
+    });
+  }
+
+  [Fact]
+  public async Task Connect_WhenCalledWithoutPlaidInstitutionId_ItShouldReturn400WithProblemDetails()
+  {
+    var jwt = JwtTokenBuilder.New()
+      .WithClaim(JwtRegisteredClaimNames.Sub, Guid.NewGuid().ToString())
+      .Build();
+
+    var json = JsonSerializer.Serialize(new { publicToken = "token" });
+    using var content = new StringContent(json, Encoding.UTF8, "application/json");
+    using var request = new HttpRequestMessage(HttpMethod.Post, ConnectUri)
+    {
+      Content = content,
+    };
+    request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", jwt);
+
+    var response = await Client.SendAsync(request, TestContext.Current.CancellationToken);
+
+    await response.Should().BeValidationProblemDetails(new Dictionary<string, string[]>()
+    {
+      ["PlaidInstitutionId"] = ["The PlaidInstitutionId field is required."],
+    });
+  }
+
+  [Fact]
+  public async Task Connect_WhenCalledWithNonExistentUser_ItShouldReturn401WithProblemDetails()
+  {
+    var jwt = JwtTokenBuilder.New()
+      .WithClaim(JwtRegisteredClaimNames.Sub, Guid.NewGuid().ToString())
+      .Build();
+
+    var json = JsonSerializer.Serialize(new
+    {
+      publicToken = "token",
+      plaidInstitutionId = "id",
+    });
+    using var content = new StringContent(json, Encoding.UTF8, "application/json");
+    using var request = new HttpRequestMessage(HttpMethod.Post, ConnectUri)
+    {
+      Content = content,
+    };
+    request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", jwt);
+
+    var response = await Client.SendAsync(request, TestContext.Current.CancellationToken);
+
+    await response.Should().BeProblemDetails(HttpStatusCode.Unauthorized);
+  }
+
+  [Fact]
+  public async Task Connect_WhenCalledWithPlaidInstitutionIdThatIsAlreadyConnected_ItShouldReturn409WithProblemDetails()
+  {
+    var (user, institution) = await ExecuteAsync(static async (context, ct, sp) =>
+    {
+      var passwordHasher = sp.GetRequiredService<IPasswordHasher>();
+      var encryptor = sp.GetRequiredService<IEncryptor>();
+
+      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(ct);
+      var user = User.From("User1", passwordHasher.Hash("@Password1"), userEncryptionKey);
+
+      var encryptedAccessToken = await encryptor.EncryptAsyncFor(user, "accessToken", ct);
+      var plaidMetadata = PlaidMetadata.From("alreadyExists", "Some Bank", encryptedAccessToken);
+      var institution = Institution.From("Some Bank", plaidMetadata);
+
+      user.AddInstitution(institution);
+
+      await context.AddAsync(user, ct);
+      await context.SaveChangesAsync(ct);
+      return (user, institution);
+    }, TestContext.Current.CancellationToken);
+
+    var jwt = JwtTokenBuilder.New()
+      .WithClaim(JwtRegisteredClaimNames.Sub, user.Id.ToString())
+      .Build();
+
+    var json = JsonSerializer.Serialize(new
+    {
+      publicToken = "token",
+      plaidInstitutionId = ((PlaidMetadata)institution.Metadata).PlaidId,
+    });
+    using var content = new StringContent(json, Encoding.UTF8, "application/json");
+    using var request = new HttpRequestMessage(HttpMethod.Post, ConnectUri)
+    {
+      Content = content,
+    };
+    request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", jwt);
+
+    var response = await Client.SendAsync(request, TestContext.Current.CancellationToken);
+
+    await response.Should().BeProblemDetails(HttpStatusCode.Conflict);
+  }
+
+  [Fact]
+  public async Task Connect_WhenCalledWithInstitutionThatIsNotConnected_ItShouldReturn200()
+  {
+    var plaidInstitutionId = "ins_109508";
+
+    var (user, publicToken) = await ExecuteAsync(async (context, ct, sp) =>
+    {
+      var plaidClient = sp.GetRequiredService<PlaidClient>();
+      var passwordHasher = sp.GetRequiredService<IPasswordHasher>();
+      var encryptor = sp.GetRequiredService<IEncryptor>();
+
+      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(ct);
+      var user = User.From("User1", passwordHasher.Hash("@Password1"), userEncryptionKey);
+
+      await context.AddAsync(user, ct);
+      await context.SaveChangesAsync(ct);
+
+      var publicToken = await plaidClient.SandboxPublicTokenCreateAsync(new()
+      {
+        InstitutionId = plaidInstitutionId,
+        InitialProducts = [Products.Transactions],
+      });
+
+      return (user, publicToken.PublicToken);
+    }, TestContext.Current.CancellationToken);
+
+    var jwt = JwtTokenBuilder.New()
+      .WithClaim(JwtRegisteredClaimNames.Sub, user.Id.ToString())
+      .Build();
+
+    var json = JsonSerializer.Serialize(new
+    {
+      publicToken,
+      plaidInstitutionId,
+    });
+    using var content = new StringContent(json, Encoding.UTF8, "application/json");
+    using var request = new HttpRequestMessage(HttpMethod.Post, ConnectUri)
+    {
+      Content = content,
+    };
+    request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", jwt);
+
+    var response = await Client.SendAsync(request, TestContext.Current.CancellationToken);
+
+    response.StatusCode.Should().Be(HttpStatusCode.OK);
+
+    var updatedUser = await ExecuteAsync(
+      async (context, ct) => await context.Set<User>()
+        .Include(u => u.Institutions)
+        .ThenInclude(i => i.Metadata)
+        .SingleAsync(u => u.Id == user.Id, ct),
+      TestContext.Current.CancellationToken
+    );
+
+    updatedUser.Institutions.Should().HaveCount(1);
+
+    var institution = updatedUser.Institutions.First();
+    institution.Name.Should().NotBeNullOrEmpty();
+
+    var metadata = institution.Metadata.As<PlaidMetadata>();
+    metadata.PlaidId.Should().Be(plaidInstitutionId);
+    metadata.PlaidName.Should().Be(institution.Name);
+    metadata.EncryptedAccessToken.Should().NotBeNullOrEmpty();
+  }
+}

tests/FiscalOS.API.Tests/Integration/IntegrationTest.cs

@@ -6,48 +6,47 @@ public abstract class IntegrationTest(TestApi testApi) : IClassFixture<TestApi>,
 
   public async ValueTask InitializeAsync()
   {
-    await ExecuteDbContextAsync(static async context =>
+    await ExecuteAsync(static async (context, ct) =>
     {
-      await context.Database.EnsureCreatedAsync();
-    });
+      await context.Database.EnsureCreatedAsync(ct);
+    }, TestContext.Current.CancellationToken);
   }
 
-  protected async Task ExecuteDbContextAsync(Func<DbContext, Task> action)
+  protected async Task ExecuteAsync(Func<DbContext, CancellationToken, Task> action, CancellationToken ct)
   {
     await using var scope = testApi.Services.CreateAsyncScope();
     var context = scope.ServiceProvider.GetRequiredService<AppDbContext>();
-    await action(context);
+    await action(context, ct);
   }
 
-  protected async Task ExecuteDbContextAsync(Func<DbContext, IServiceProvider, Task> action)
+  protected async Task ExecuteAsync(Func<DbContext, CancellationToken, IServiceProvider, Task> action, CancellationToken ct)
   {
     await using var scope = testApi.Services.CreateAsyncScope();
     var context = scope.ServiceProvider.GetRequiredService<AppDbContext>();
-    await action(context, scope.ServiceProvider);
+    await action(context, ct, scope.ServiceProvider);
   }
 
-  protected async Task<T> ExecuteDbContextAsync<T>(Func<DbContext, Task<T>> action)
+  protected async Task<T> ExecuteAsync<T>(Func<DbContext, CancellationToken, Task<T>> action, CancellationToken ct)
   {
     await using var scope = testApi.Services.CreateAsyncScope();
     var context = scope.ServiceProvider.GetRequiredService<AppDbContext>();
-    return await action(context);
+    return await action(context, ct);
   }
 
-  protected async Task<T> ExecuteDbContextAsync<T>(Func<DbContext, IServiceProvider, Task<T>> action)
+  protected async Task<T> ExecuteAsync<T>(Func<DbContext, CancellationToken, IServiceProvider, Task<T>> action, CancellationToken ct)
   {
     await using var scope = testApi.Services.CreateAsyncScope();
     var context = scope.ServiceProvider.GetRequiredService<AppDbContext>();
-    return await action(context, scope.ServiceProvider);
+    return await action(context, ct, scope.ServiceProvider);
   }
 
   public async ValueTask DisposeAsync()
   {
-    await ExecuteDbContextAsync(static async context =>
+    await ExecuteAsync(static async (context, ct) =>
     {
-      await context.Database.EnsureDeletedAsync();
-    });
+      await context.Database.EnsureDeletedAsync(ct);
+    }, TestContext.Current.CancellationToken);
 
     GC.SuppressFinalize(this);
   }
-
 }

tests/FiscalOS.API.Tests/Integration/LoginTests.cs

@@ -1,3 +1,5 @@
+using FiscalOS.API.Tests.Common;
+
 namespace FiscalOS.API.Tests.Integration;
 
 public class LoginTests(TestApi testApi) : IntegrationTest(testApi)
@@ -36,16 +38,16 @@ public class LoginTests(TestApi testApi) : IntegrationTest(testApi)
   [Fact]
   public async Task Login_WhenUserExistsButPasswordIsIncorrect_ItShouldReturn401WithProblemDetails()
   {
-    await ExecuteDbContextAsync(static async (context, sp) =>
+    await ExecuteAsync(static async (context, ct, sp) =>
     {
       var passwordHasher = sp.GetRequiredService<IPasswordHasher>();
       var encryptor = sp.GetRequiredService<IEncryptor>();
 
-      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(TestContext.Current.CancellationToken);
+      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(ct);
       context.Add(User.From("Stevan", passwordHasher.Hash("@Password1"), userEncryptionKey));
 
-      await context.SaveChangesAsync(TestContext.Current.CancellationToken);
-    });
+      await context.SaveChangesAsync(ct);
+    }, TestContext.Current.CancellationToken);
 
     var req = new
     {
@@ -61,16 +63,16 @@ public class LoginTests(TestApi testApi) : IntegrationTest(testApi)
   [Fact]
   public async Task Login_WhenUserExistsAndPasswordIsCorrect_ItShouldReturn200WithJwtTokenAndSetRefreshCookie()
   {
-    await ExecuteDbContextAsync(static async (context, sp) =>
+    await ExecuteAsync(static async (context, ct, sp) =>
     {
       var passwordHasher = sp.GetRequiredService<IPasswordHasher>();
       var encryptor = sp.GetRequiredService<IEncryptor>();
 
-      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(TestContext.Current.CancellationToken);
+      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(ct);
       context.Add(User.From("Stevan", passwordHasher.Hash("@Password1"), userEncryptionKey));
 
-      await context.SaveChangesAsync(TestContext.Current.CancellationToken);
-    });
+      await context.SaveChangesAsync(ct);
+    }, TestContext.Current.CancellationToken);
 
     var req = new
     {
@@ -94,7 +96,7 @@ public class LoginValidationTestCases : TheoryData<LoginValidationTestCase>
       "No username or password",
       string.Empty,
       string.Empty,
-      new Dictionary<string, string[]>()
+      new SerializableDictionary<string, string[]>()
       {
         ["Username"] = ["The Username field is required."],
         ["Password"] = ["The Password field is required."]
@@ -105,7 +107,7 @@ public class LoginValidationTestCases : TheoryData<LoginValidationTestCase>
       "No username",
       string.Empty,
       "@Password1",
-      new Dictionary<string, string[]>()
+      new SerializableDictionary<string, string[]>()
       {
         ["Username"] = ["The Username field is required."],
       }
@@ -115,7 +117,7 @@ public class LoginValidationTestCases : TheoryData<LoginValidationTestCase>
       "No password",
       "Stevan",
       string.Empty,
-      new Dictionary<string, string[]>()
+      new SerializableDictionary<string, string[]>()
       {
         ["Password"] = ["The Password field is required."]
       }
@@ -128,7 +130,7 @@ public record LoginValidationTestCase : IXunitSerializable
   public string Name { get; private set; } = string.Empty;
   public string Username { get; private set; } = string.Empty;
   public string Password { get; private set; } = string.Empty;
-  public Dictionary<string, string[]> ExpectedErrors { get; private set; } = [];
+  public SerializableDictionary<string, string[]> ExpectedErrors { get; private set; } = [];
 
   public override string ToString()
   {
@@ -143,7 +145,7 @@ public record LoginValidationTestCase : IXunitSerializable
     string name,
     string username,
     string password,
-    Dictionary<string, string[]> expectedErrors
+    SerializableDictionary<string, string[]> expectedErrors
   )
   {
     Name = name;
@@ -157,7 +159,7 @@ public record LoginValidationTestCase : IXunitSerializable
     Name = info.GetValue<string>(nameof(Name)) ?? string.Empty;
     Username = info.GetValue<string>(nameof(Username)) ?? string.Empty;
     Password = info.GetValue<string>(nameof(Password)) ?? string.Empty;
-    ExpectedErrors = info.GetValue<Dictionary<string, string[]>>(nameof(ExpectedErrors)) ?? [];
+    ExpectedErrors = info.GetValue<SerializableDictionary<string, string[]>>(nameof(ExpectedErrors)) ?? [];
   }
 
   public void Serialize(IXunitSerializationInfo info)

tests/FiscalOS.API.Tests/Integration/RefreshTests.cs

@@ -31,14 +31,14 @@ public class RefreshTests(TestApi testApi) : IntegrationTest(testApi)
   [Fact]
   public async Task Refresh_WhenCalledWithTokenBelongingToDifferentUser_ItShouldReturn403WithProblemDetails()
   {
-    var (users, refreshToken) = await ExecuteDbContextAsync(static async (context, sp) =>
+    var (users, refreshToken) = await ExecuteAsync(static async (context, ct, sp) =>
     {
       var passwordHasher = sp.GetRequiredService<IPasswordHasher>();
       var tokenGenerator = sp.GetRequiredService<ITokenGenerator>();
       var encryptor = sp.GetRequiredService<IEncryptor>();
 
-      var user1EncryptionKey = await encryptor.GenerateEncryptedKeyAsync(TestContext.Current.CancellationToken);
-      var user2EncryptionKey = await encryptor.GenerateEncryptedKeyAsync(TestContext.Current.CancellationToken);
+      var user1EncryptionKey = await encryptor.GenerateEncryptedKeyAsync(ct);
+      var user2EncryptionKey = await encryptor.GenerateEncryptedKeyAsync(ct);
       var user1 = User.From("User1", passwordHasher.Hash("@Password1"), user1EncryptionKey);
       var user2 = User.From("User2", passwordHasher.Hash("@Password2"), user2EncryptionKey);
       var refreshToken1 = tokenGenerator.GenerateRefreshToken(user2);
@@ -49,9 +49,9 @@ public class RefreshTests(TestApi testApi) : IntegrationTest(testApi)
       context.Add(user1);
       context.Add(user2);
 
-      await context.SaveChangesAsync(TestContext.Current.CancellationToken);
+      await context.SaveChangesAsync(ct);
       return (new User[] { user1, user2 }, refreshToken1);
-    });
+    }, TestContext.Current.CancellationToken);
 
     var jwt = JwtTokenBuilder.New()
       .WithClaim(JwtRegisteredClaimNames.Sub, users[0].Id.ToString())
@@ -65,11 +65,12 @@ public class RefreshTests(TestApi testApi) : IntegrationTest(testApi)
 
     await response.Should().BeProblemDetails(HttpStatusCode.Forbidden);
 
-    var unrevokedTokensCountForUser2 = await ExecuteDbContextAsync(
-      async context => await context.Set<RefreshToken>()
+    var unrevokedTokensCountForUser2 = await ExecuteAsync(
+      async (context, ct) => await context.Set<RefreshToken>()
         .Include(t => t.User)
         .Where(t => t.UserId == users[1].Id && t.Revoked == false)
-        .CountAsync()
+        .CountAsync(ct),
+      TestContext.Current.CancellationToken
     );
 
     unrevokedTokensCountForUser2.Should().Be(0);
@@ -78,13 +79,13 @@ public class RefreshTests(TestApi testApi) : IntegrationTest(testApi)
   [Fact]
   public async Task Refresh_WhenCalledWithRevokedRefreshToken_ItShouldReturn400WithProblemDetails()
   {
-    var (user, refreshToken) = await ExecuteDbContextAsync(static async (context, sp) =>
+    var (user, refreshToken) = await ExecuteAsync(static async (context, ct, sp) =>
     {
       var passwordHasher = sp.GetRequiredService<IPasswordHasher>();
       var tokenGenerator = sp.GetRequiredService<ITokenGenerator>();
       var encryptor = sp.GetRequiredService<IEncryptor>();
 
-      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(TestContext.Current.CancellationToken);
+      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(ct);
       var user = User.From("User1", passwordHasher.Hash("@Password1"), userEncryptionKey);
       var refreshToken = tokenGenerator.GenerateRefreshToken(user);
       refreshToken.Revoke();
@@ -93,9 +94,9 @@ public class RefreshTests(TestApi testApi) : IntegrationTest(testApi)
 
       context.Add(user);
 
-      await context.SaveChangesAsync(TestContext.Current.CancellationToken);
+      await context.SaveChangesAsync(ct);
       return (user, refreshToken);
-    });
+    }, TestContext.Current.CancellationToken);
 
     var jwt = JwtTokenBuilder.New()
       .WithClaim(JwtRegisteredClaimNames.Sub, user.Id.ToString())
@@ -113,23 +114,23 @@ public class RefreshTests(TestApi testApi) : IntegrationTest(testApi)
   [Fact]
   public async Task Refresh_WhenCalledWithExpiredRefreshToken_ItShouldReturn400WithProblemDetails()
   {
-    var (user, refreshToken) = await ExecuteDbContextAsync(static async (context, sp) =>
+    var (user, refreshToken) = await ExecuteAsync(static async (context, ct, sp) =>
     {
       var passwordHasher = sp.GetRequiredService<IPasswordHasher>();
       var tokenGenerator = sp.GetRequiredService<ITokenGenerator>();
       var timeProvider = sp.GetRequiredService<TimeProvider>();
       var encryptor = sp.GetRequiredService<IEncryptor>();
 
-      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(TestContext.Current.CancellationToken);
+      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(ct);
       var user = User.From("User1", passwordHasher.Hash("@Password1"), userEncryptionKey);
       var refreshToken = RefreshToken.From(user.Id, "expiredtoken", timeProvider.GetUtcNow().AddHours(-1));
       user.AddRefreshToken(refreshToken);
 
       context.Add(user);
 
-      await context.SaveChangesAsync(TestContext.Current.CancellationToken);
+      await context.SaveChangesAsync(ct);
       return (user, refreshToken);
-    });
+    }, TestContext.Current.CancellationToken);
 
     var jwt = JwtTokenBuilder.New()
       .WithClaim(JwtRegisteredClaimNames.Sub, user.Id.ToString())
@@ -149,23 +150,23 @@ public class RefreshTests(TestApi testApi) : IntegrationTest(testApi)
   [InlineData(-5)]
   public async Task Refresh_WhenCalledWithValidRefreshTokenAndExpiredOrNotExpiredAccessToken_ItShouldReturn200WithNewTokensAndSetRefreshCookie(int accessTokenExpiresAtOffset)
   {
-    var (user, refreshToken) = await ExecuteDbContextAsync(static async (context, sp) =>
+    var (user, refreshToken) = await ExecuteAsync(static async (context, ct, sp) =>
     {
       var passwordHasher = sp.GetRequiredService<IPasswordHasher>();
       var tokenGenerator = sp.GetRequiredService<ITokenGenerator>();
       var timeProvider = sp.GetRequiredService<TimeProvider>();
       var encryptor = sp.GetRequiredService<IEncryptor>();
 
-      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(TestContext.Current.CancellationToken);
+      var userEncryptionKey = await encryptor.GenerateEncryptedKeyAsync(ct);
       var user = User.From("User1", passwordHasher.Hash("@Password1"), userEncryptionKey);
       var refreshToken = tokenGenerator.GenerateRefreshToken(user);
       user.AddRefreshToken(refreshToken);
 
       context.Add(user);
 
-      await context.SaveChangesAsync(TestContext.Current.CancellationToken);
+      await context.SaveChangesAsync(ct);
       return (user, refreshToken);
-    });
+    }, TestContext.Current.CancellationToken);
 
     var jwt = JwtTokenBuilder.New()
       .WithClaim(JwtRegisteredClaimNames.Sub, user.Id.ToString())
@@ -181,20 +182,22 @@ public class RefreshTests(TestApi testApi) : IntegrationTest(testApi)
     response.Should().HaveSetCookieHeader("fiscalos_refresh_cookie");
     await response.Should().BeJsonContentOfType<Refresh.Response>(HttpStatusCode.OK);
 
-    var oldRefreshTokenInDb = await ExecuteDbContextAsync(
-      async context => await context.Set<RefreshToken>()
+    var oldRefreshTokenInDb = await ExecuteAsync(
+      async (context, ct) => await context.Set<RefreshToken>()
         .Include(t => t.User)
         .Where(t => t.UserId == user.Id && t.Token == refreshToken.Token && t.Revoked == true)
-        .SingleOrDefaultAsync()
+        .SingleOrDefaultAsync(ct),
+      TestContext.Current.CancellationToken
     );
 
     oldRefreshTokenInDb.Should().NotBeNull();
 
-    var newRefreshTokenInDb = await ExecuteDbContextAsync(
-      async context => await context.Set<RefreshToken>()
+    var newRefreshTokenInDb = await ExecuteAsync(
+      async (context, ct) => await context.Set<RefreshToken>()
         .Include(t => t.User)
         .Where(t => t.UserId == user.Id && t.Revoked == false && t.Token != refreshToken.Token)
-        .SingleOrDefaultAsync()
+        .SingleOrDefaultAsync(ct),
+      TestContext.Current.CancellationToken
     );
 
     newRefreshTokenInDb.Should().NotBeNull();

tests/FiscalOS.API.Tests/Usings.cs

@@ -4,6 +4,8 @@ global using System.Net.Http.Headers;
 global using System.Net.Http.Json;
 global using System.Security.Claims;
 global using System.Security.Cryptography;
+global using System.Text;
+global using System.Text.Json;
 
 global using AwesomeAssertions.Execution;
 global using AwesomeAssertions.Primitives;
@@ -13,9 +15,13 @@ global using FiscalOS.API.Tests.Infra;
 global using FiscalOS.Core.Authentication;
 global using FiscalOS.Core.Identity;
 global using FiscalOS.Core.Security;
+global using FiscalOS.Infra.Accounts.Plaid;
 global using FiscalOS.Infra.Authentication;
 global using FiscalOS.Infra.Data;
 
+global using Going.Plaid;
+global using Going.Plaid.Entity;
+
 global using Microsoft.AspNetCore.Hosting;
 global using Microsoft.AspNetCore.Mvc;
 global using Microsoft.AspNetCore.Mvc.Testing;