database/migrations/V019_ROLLBACK.sql

@@ -0,0 +1,71 @@
+-- V019_ROLLBACK.sql
+-- PRD-003: Reversa de V019__create_product_prices.sql.
+--
+-- Pasos:
+--   1. Deshabilita SYSTEM_VERSIONING en dbo.ProductPrices (requerido antes de DROP TABLE).
+--   2. Elimina el PERIOD FOR SYSTEM_TIME y las columnas hidden SysStartTime/SysEndTime.
+--   3. Drop de dbo.ProductPrices_History.
+--   4. Drop de dbo.ProductPrices (y sus constraints + índices en cascada).
+--   5. Drop de dbo.usp_AddProductPrice.
+--
+-- ADVERTENCIA: destruye todo el historial de precios. Ejecutar sólo en DEV o TEST.
+-- Run on: SIGCM2 (dev), SIGCM2_Test_App, SIGCM2_Test_Api.
+
+SET QUOTED_IDENTIFIER ON;
+SET ANSI_NULLS ON;
+SET NOCOUNT ON;
+GO
+
+-- 1. Deshabilita SYSTEM_VERSIONING (imprescindible antes de DROP TABLE temporal).
+IF EXISTS (SELECT 1 FROM sys.tables WHERE object_id = OBJECT_ID('dbo.ProductPrices') AND temporal_type = 2)
+BEGIN
+    ALTER TABLE dbo.ProductPrices SET (SYSTEM_VERSIONING = OFF);
+    PRINT 'ProductPrices: SYSTEM_VERSIONING = OFF.';
+END
+GO
+
+-- 2. Elimina el PERIOD y las hidden cols (si existen, independientemente del versioning).
+IF COL_LENGTH('dbo.ProductPrices', 'SysStartTime') IS NOT NULL
+BEGIN
+    ALTER TABLE dbo.ProductPrices
+    DROP PERIOD FOR SYSTEM_TIME;
+
+    -- Drop default constraints antes de drop de columnas.
+    IF EXISTS (SELECT 1 FROM sys.default_constraints WHERE name = 'DF_ProductPrices_SysStartTime')
+        ALTER TABLE dbo.ProductPrices DROP CONSTRAINT DF_ProductPrices_SysStartTime;
+    IF EXISTS (SELECT 1 FROM sys.default_constraints WHERE name = 'DF_ProductPrices_SysEndTime')
+        ALTER TABLE dbo.ProductPrices DROP CONSTRAINT DF_ProductPrices_SysEndTime;
+
+    ALTER TABLE dbo.ProductPrices DROP COLUMN SysStartTime;
+    ALTER TABLE dbo.ProductPrices DROP COLUMN SysEndTime;
+    PRINT 'ProductPrices: PERIOD + hidden cols dropped.';
+END
+GO
+
+-- 3. Drop de la history table.
+IF OBJECT_ID(N'dbo.ProductPrices_History', N'U') IS NOT NULL
+BEGIN
+    DROP TABLE dbo.ProductPrices_History;
+    PRINT 'Table dbo.ProductPrices_History dropped.';
+END
+GO
+
+-- 4. Drop de la tabla principal (constraints + índices en cascada).
+IF OBJECT_ID(N'dbo.ProductPrices', N'U') IS NOT NULL
+BEGIN
+    DROP TABLE dbo.ProductPrices;
+    PRINT 'Table dbo.ProductPrices dropped.';
+END
+GO
+
+-- 5. Drop del SP.
+IF OBJECT_ID(N'dbo.usp_AddProductPrice', N'P') IS NOT NULL
+BEGIN
+    DROP PROCEDURE dbo.usp_AddProductPrice;
+    PRINT 'Procedure dbo.usp_AddProductPrice dropped.';
+END
+GO
+
+PRINT '';
+PRINT 'V019 rollback complete — dbo.ProductPrices, dbo.ProductPrices_History, dbo.usp_AddProductPrice removed.';
+GO

database/migrations/V019__create_product_prices.sql

@@ -0,0 +1,196 @@
+-- V019__create_product_prices.sql
+-- PRD-003: ProductPrices — historial de precios por Producto con vigencia civil (Cat2).
+--
+-- Cambios:
+--   1. dbo.ProductPrices (FK Product, SYSTEM_VERSIONING ON, retention 10 años).
+--   2. Índices: filtered UQ un único activo; cover compuesto para GetPriceAt.
+--   3. SP dbo.usp_AddProductPrice (SERIALIZABLE + UPDLOCK, cierre atómico forward-only).
+--
+-- Patrón: V018 (SYSTEM_VERSIONING + PAGE compression).
+-- Idempotente: seguro para re-ejecutar.
+-- Reversa: V019_ROLLBACK.sql.
+-- Run on: SIGCM2 (dev), SIGCM2_Test_App, SIGCM2_Test_Api.
+--
+-- Notas:
+--   - SysStartTime/SysEndTime como nombres de cols HIDDEN (no ValidFrom/ValidTo):
+--     evita colisión con las business cols PriceValidFrom/PriceValidTo (D1).
+--   - DECIMAL(12,2) para Price (distinto de Product.BasePrice DECIMAL(18,4)) — precios retail
+--     en pesos con 2 decimales; la diferencia es intencional (D6).
+--   - Sin seed inicial — Product.BasePrice queda ortogonal como fallback (OQ-B, D8).
+--   - Forward-only estricto en SP: THROW 50409 si new PVF <= active PVF (no solo <).
+--
+-- SDD Design: engram sdd/prd-003-product-prices-historicos/design
+
+SET QUOTED_IDENTIFIER ON;
+SET ANSI_NULLS ON;
+SET NOCOUNT ON;
+GO
+
+-- ═══════════════════════════════════════════════════════════════════════
+-- 1. dbo.ProductPrices
+-- ═══════════════════════════════════════════════════════════════════════
+
+IF OBJECT_ID(N'dbo.ProductPrices', N'U') IS NULL
+BEGIN
+    CREATE TABLE dbo.ProductPrices (
+        Id              BIGINT IDENTITY(1,1) NOT NULL
+            CONSTRAINT PK_ProductPrices PRIMARY KEY,
+        ProductId       INT           NOT NULL,
+        Price           DECIMAL(12,2) NOT NULL,
+        PriceValidFrom  DATE          NOT NULL,
+        PriceValidTo    DATE          NULL,
+        FechaCreacion   DATETIME2(3)  NOT NULL
+            CONSTRAINT DF_ProductPrices_FechaCreacion DEFAULT(SYSUTCDATETIME()),
+        CONSTRAINT FK_ProductPrices_Product
+            FOREIGN KEY (ProductId) REFERENCES dbo.Product(Id) ON DELETE NO ACTION,
+        CONSTRAINT CK_ProductPrices_Price_Positive
+            CHECK (Price > 0),
+        CONSTRAINT CK_ProductPrices_ValidRange
+            CHECK (PriceValidTo IS NULL OR PriceValidTo >= PriceValidFrom)
+    );
+    PRINT 'Table dbo.ProductPrices created.';
+END
+ELSE
+    PRINT 'Table dbo.ProductPrices already exists — skip.';
+GO
+
+-- ═══════════════════════════════════════════════════════════════════════
+-- 2. SYSTEM_VERSIONING — ProductPrices
+--    Las hidden cols se llaman SysStartTime/SysEndTime para evitar
+--    colisión con las business cols PriceValidFrom/PriceValidTo (D1).
+-- ═══════════════════════════════════════════════════════════════════════
+
+IF COL_LENGTH('dbo.ProductPrices', 'SysStartTime') IS NULL
+BEGIN
+    ALTER TABLE dbo.ProductPrices
+    ADD
+        SysStartTime DATETIME2(3) GENERATED ALWAYS AS ROW START HIDDEN NOT NULL
+            CONSTRAINT DF_ProductPrices_SysStartTime DEFAULT(SYSUTCDATETIME()),
+        SysEndTime   DATETIME2(3) GENERATED ALWAYS AS ROW END   HIDDEN NOT NULL
+            CONSTRAINT DF_ProductPrices_SysEndTime   DEFAULT(CONVERT(DATETIME2(3),'9999-12-31 23:59:59.999')),
+        PERIOD FOR SYSTEM_TIME (SysStartTime, SysEndTime);
+    PRINT 'ProductPrices: PERIOD FOR SYSTEM_TIME added (SysStartTime/SysEndTime).';
+END
+GO
+
+IF NOT EXISTS (SELECT 1 FROM sys.tables WHERE object_id = OBJECT_ID('dbo.ProductPrices') AND temporal_type = 2)
+BEGIN
+    ALTER TABLE dbo.ProductPrices
+    SET (SYSTEM_VERSIONING = ON (
+        HISTORY_TABLE = dbo.ProductPrices_History,
+        HISTORY_RETENTION_PERIOD = 10 YEARS
+    ));
+    PRINT 'ProductPrices: SYSTEM_VERSIONING = ON (history: dbo.ProductPrices_History, retention: 10 years).';
+END
+ELSE
+    PRINT 'ProductPrices: SYSTEM_VERSIONING already ON — skip.';
+GO
+
+IF EXISTS (SELECT 1 FROM sys.tables WHERE name = 'ProductPrices_History' AND schema_id = SCHEMA_ID('dbo'))
+   AND NOT EXISTS (
+       SELECT 1 FROM sys.partitions p
+       JOIN sys.tables t ON t.object_id = p.object_id
+       WHERE t.name = 'ProductPrices_History' AND p.data_compression = 2
+   )
+BEGIN
+    ALTER TABLE dbo.ProductPrices_History REBUILD WITH (DATA_COMPRESSION = PAGE);
+    PRINT 'ProductPrices_History: rebuilt with PAGE compression.';
+END
+GO
+
+-- ═══════════════════════════════════════════════════════════════════════
+-- 3. Índices
+-- ═══════════════════════════════════════════════════════════════════════
+
+-- Un único activo por producto (imposibilita violar a nivel BD).
+IF NOT EXISTS (SELECT 1 FROM sys.indexes WHERE name = 'UX_ProductPrices_Active' AND object_id = OBJECT_ID('dbo.ProductPrices'))
+BEGIN
+    CREATE UNIQUE INDEX UX_ProductPrices_Active
+        ON dbo.ProductPrices (ProductId)
+        WHERE PriceValidTo IS NULL;
+    PRINT 'Index UX_ProductPrices_Active created.';
+END
+GO
+
+-- Cover para GetPriceAt / GetByProductIdAsync (ProductId + PriceValidFrom con INCLUDEs).
+IF NOT EXISTS (SELECT 1 FROM sys.indexes WHERE name = 'IX_ProductPrices_Lookup' AND object_id = OBJECT_ID('dbo.ProductPrices'))
+BEGIN
+    CREATE INDEX IX_ProductPrices_Lookup
+        ON dbo.ProductPrices (ProductId, PriceValidFrom DESC)
+        INCLUDE (Price, PriceValidTo);
+    PRINT 'Index IX_ProductPrices_Lookup created.';
+END
+GO
+
+-- ═══════════════════════════════════════════════════════════════════════
+-- 4. SP — dbo.usp_AddProductPrice
+--    Cierre atómico forward-only: SERIALIZABLE + UPDLOCK + HOLDLOCK.
+--    Params de salida: @NewId (BIGINT), @ClosedId (BIGINT — NULL si primer precio).
+-- ═══════════════════════════════════════════════════════════════════════
+GO
+CREATE OR ALTER PROCEDURE dbo.usp_AddProductPrice
+    @ProductId      INT,
+    @Price          DECIMAL(12,2),
+    @PriceValidFrom DATE,
+    @NewId          BIGINT OUTPUT,
+    @ClosedId       BIGINT OUTPUT
+AS
+BEGIN
+    SET NOCOUNT ON;
+    SET XACT_ABORT ON;
+    SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+
+    BEGIN TRY
+        BEGIN TRANSACTION;
+
+        -- Validación: producto debe existir y estar activo.
+        IF NOT EXISTS (SELECT 1 FROM dbo.Product WITH (NOLOCK) WHERE Id = @ProductId AND IsActive = 1)
+        BEGIN
+            ROLLBACK;
+            THROW 50404, 'Product not found or inactive', 1;
+        END
+
+        -- Lee activo con UPDLOCK + HOLDLOCK — bloquea el range key del filtered index.
+        DECLARE @ActiveId BIGINT, @ActivePVF DATE;
+        SELECT TOP 1
+            @ActiveId  = Id,
+            @ActivePVF = PriceValidFrom
+        FROM dbo.ProductPrices WITH (UPDLOCK, HOLDLOCK, ROWLOCK)
+        WHERE ProductId = @ProductId AND PriceValidTo IS NULL;
+
+        -- Forward-only estricto: el nuevo PVF debe ser ESTRICTAMENTE mayor al activo.
+        IF @ActiveId IS NOT NULL AND @PriceValidFrom <= @ActivePVF
+        BEGIN
+            ROLLBACK;
+            THROW 50409, 'ProductPriceForwardOnly: new PriceValidFrom must be > active.PriceValidFrom', 1;
+        END
+
+        -- Cierra el activo previo: PVT = PVF(nuevo) - 1 día.
+        IF @ActiveId IS NOT NULL
+        BEGIN
+            UPDATE dbo.ProductPrices
+               SET PriceValidTo = DATEADD(DAY, -1, @PriceValidFrom)
+             WHERE Id = @ActiveId;
+            SET @ClosedId = @ActiveId;
+        END
+        ELSE
+            SET @ClosedId = NULL;
+
+        -- Inserta el nuevo activo.
+        INSERT INTO dbo.ProductPrices (ProductId, Price, PriceValidFrom, PriceValidTo)
+        VALUES (@ProductId, @Price, @PriceValidFrom, NULL);
+        SET @NewId = SCOPE_IDENTITY();
+
+        COMMIT TRANSACTION;
+    END TRY
+    BEGIN CATCH
+        IF XACT_STATE() <> 0 ROLLBACK TRANSACTION;
+        THROW;
+    END CATCH
+END
+GO
+
+PRINT '';
+PRINT 'V019 applied — dbo.ProductPrices (temporal, retention 10y) + UX_ProductPrices_Active + IX_ProductPrices_Lookup + usp_AddProductPrice.';
+PRINT 'Next migration: V020 (TBD).';
+GO

src/api/SIGCM2.Api/Controllers/ProductPricesController.cs

@@ -0,0 +1,93 @@
+using FluentValidation;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using SIGCM2.Api.Authorization;
+using SIGCM2.Application.Abstractions;
+using SIGCM2.Application.Products.Prices;
+using SIGCM2.Application.Products.Prices.AddPrice;
+using SIGCM2.Application.Products.Prices.GetHistory;
+
+namespace SIGCM2.Api.Controllers;
+
+/// <summary>
+/// PRD-003: ProductPrices historic pricing management.
+/// Read endpoint at GET /api/v1/products/{id}/prices — requires authentication (any role).
+/// Write endpoint at POST /api/v1/admin/products/{id}/prices — requires 'catalogo:productos:gestionar'.
+/// </summary>
+[ApiController]
+public sealed class ProductPricesController : ControllerBase
+{
+    private readonly IDispatcher _dispatcher;
+    private readonly IValidator<AddProductPriceCommand> _addValidator;
+
+    public ProductPricesController(
+        IDispatcher dispatcher,
+        IValidator<AddProductPriceCommand> addValidator)
+    {
+        _dispatcher = dispatcher;
+        _addValidator = addValidator;
+    }
+
+    // ── READ endpoint ──────────────────────────────────────────────────────────
+
+    /// <summary>
+    /// Returns the full price history for a Product, ordered descending by PriceValidFrom.
+    /// Returns 200 with empty array if the product has no prices yet.
+    /// Returns 404 if the product does not exist.
+    /// </summary>
+    [HttpGet("api/v1/products/{id:int}/prices")]
+    [Authorize]
+    [ProducesResponseType(typeof(IReadOnlyList<ProductPriceDto>), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<IActionResult> GetProductPrices([FromRoute] int id)
+    {
+        var query = new GetProductPricesQuery(id);
+        var result = await _dispatcher.Send<GetProductPricesQuery, IReadOnlyList<ProductPriceDto>>(query);
+        return Ok(result);
+    }
+
+    // ── WRITE endpoint ─────────────────────────────────────────────────────────
+
+    /// <summary>
+    /// Adds a new price to a Product. Closes the current active price if one exists.
+    /// PriceValidFrom must be >= today_AR and strictly greater than the active price's PriceValidFrom.
+    /// Returns 201 Created with Location header pointing to GET /api/v1/products/{id}/prices.
+    /// </summary>
+    [HttpPost("api/v1/admin/products/{id:int}/prices")]
+    [RequirePermission("catalogo:productos:gestionar")]
+    [ProducesResponseType(typeof(AddProductPriceResponse), StatusCodes.Status201Created)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status401Unauthorized)]
+    [ProducesResponseType(StatusCodes.Status403Forbidden)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    [ProducesResponseType(StatusCodes.Status409Conflict)]
+    public async Task<IActionResult> AddProductPrice(
+        [FromRoute] int id,
+        [FromBody] AddProductPriceRequest request)
+    {
+        var command = new AddProductPriceCommand(
+            ProductId: id,
+            Price: request.Price,
+            PriceValidFrom: request.PriceValidFrom);
+
+        var validation = await _addValidator.ValidateAsync(command);
+        if (!validation.IsValid)
+        {
+            var errors = validation.Errors
+                .GroupBy(e => e.PropertyName)
+                .ToDictionary(g => g.Key, g => g.Select(e => e.ErrorMessage).ToArray());
+            return BadRequest(new { errors });
+        }
+
+        var result = await _dispatcher.Send<AddProductPriceCommand, AddProductPriceResponse>(command);
+        return CreatedAtAction(nameof(GetProductPrices), new { id }, result);
+    }
+}
+
+// ── Request body record ───────────────────────────────────────────────────────
+
+/// <summary>PRD-003: Add ProductPrice request body.</summary>
+public sealed record AddProductPriceRequest(
+    decimal Price,
+    DateOnly PriceValidFrom);

src/api/SIGCM2.Api/Filters/ExceptionFilter.cs

@@ -475,6 +475,45 @@ public sealed class ExceptionFilter : IExceptionFilter
                 context.ExceptionHandled = true;
                 break;
 
+            // PRD-003: ProductPrices exceptions
+            case ProductPriceForwardOnlyException forwardOnlyEx:
+                context.Result = new ObjectResult(new
+                {
+                    error = "product_price_forward_only",
+                    message = forwardOnlyEx.Message,
+                    productId = forwardOnlyEx.ProductId
+                })
+                {
+                    StatusCode = StatusCodes.Status409Conflict
+                };
+                context.ExceptionHandled = true;
+                break;
+
+            case ProductPriceInvalidException priceInvalidEx:
+                context.Result = new ObjectResult(new
+                {
+                    error = "product_price_invalid",
+                    message = priceInvalidEx.Message,
+                    field = priceInvalidEx.Field
+                })
+                {
+                    StatusCode = StatusCodes.Status400BadRequest
+                };
+                context.ExceptionHandled = true;
+                break;
+
+            case ProductSinPrecioActivoException sinPrecioEx:
+                context.Result = new ObjectResult(new
+                {
+                    error = "product_sin_precio_activo",
+                    message = sinPrecioEx.Message
+                })
+                {
+                    StatusCode = StatusCodes.Status404NotFound
+                };
+                context.ExceptionHandled = true;
+                break;
+
             // PRD-002: Product exceptions
             case ProductNotFoundException productNotFoundEx:
                 context.Result = new ObjectResult(new

src/api/SIGCM2.Application/Abstractions/Persistence/IProductPriceRepository.cs

@@ -0,0 +1,40 @@
+using SIGCM2.Domain.Entities;
+
+namespace SIGCM2.Application.Abstractions.Persistence;
+
+/// <summary>
+/// PRD-003 — Write + query access to dbo.ProductPrices.
+/// Implemented by ProductPriceRepository (Dapper) in Infrastructure.
+/// </summary>
+public interface IProductPriceRepository
+{
+    /// <summary>
+    /// Invokes dbo.usp_AddProductPrice inside the ambient TransactionScope.
+    /// Returns (newId, closedId?). Throws:
+    ///   - ProductPriceForwardOnlyException on SQL THROW 50409 or unique index violation (2601/2627).
+    ///   - ProductNotFoundException on SQL THROW 50404.
+    /// </summary>
+    Task<(long NewId, long? ClosedId)> AddAsync(
+        int productId,
+        decimal price,
+        DateOnly priceValidFrom,
+        CancellationToken ct = default);
+
+    /// <summary>
+    /// Returns all price rows for the product, ordered descending by PriceValidFrom (active first).
+    /// Returns empty list when the product has no price history.
+    /// </summary>
+    Task<IReadOnlyList<ProductPrice>> GetByProductIdAsync(
+        int productId,
+        CancellationToken ct = default);
+
+    /// <summary>
+    /// Returns the ProductPrice row whose window [PriceValidFrom, PriceValidTo] covers the given
+    /// civil date, or null if no row matches (no history, or date is before any recorded price).
+    /// Used by ProductPricingService.GetPriceAtAsync.
+    /// </summary>
+    Task<ProductPrice?> GetActiveAsync(
+        int productId,
+        DateOnly date,
+        CancellationToken ct = default);
+}

src/api/SIGCM2.Application/DependencyInjection.cs

@@ -74,6 +74,10 @@ using SIGCM2.Application.Products.Update;
 using SIGCM2.Application.Products.Deactivate;
 using SIGCM2.Application.Products.GetById;
 using SIGCM2.Application.Products.List;
+using SIGCM2.Application.Products.Prices;
+using SIGCM2.Application.Products.Prices.AddPrice;
+using SIGCM2.Application.Products.Prices.GetHistory;
+using SIGCM2.Application.Products.Pricing;
 using SIGCM2.Application.ProductTypes.Create;
 using SIGCM2.Application.ProductTypes.Update;
 using SIGCM2.Application.ProductTypes.Deactivate;
@@ -182,6 +186,11 @@ public static class DependencyInjection
         services.AddScoped<ICommandHandler<GetProductByIdQuery, ProductDetailDto>, GetProductByIdQueryHandler>();
         services.AddScoped<ICommandHandler<ListProductsQuery, PagedResult<ProductListItemDto>>, ListProductsQueryHandler>();
 
+        // ProductPrices (PRD-003)
+        services.AddScoped<ICommandHandler<AddProductPriceCommand, AddProductPriceResponse>, AddProductPriceCommandHandler>();
+        services.AddScoped<ICommandHandler<GetProductPricesQuery, IReadOnlyList<ProductPriceDto>>, GetProductPricesQueryHandler>();
+        services.AddScoped<IProductPricingService, ProductPricingService>();
+
         // ProductTypes (PRD-001)
         // IProductQueryRepository is now bound in Infrastructure DI (PRD-002) against dbo.Product.
 

src/api/SIGCM2.Application/Products/Prices/AddPrice/AddProductPriceCommand.cs

@@ -0,0 +1,10 @@
+namespace SIGCM2.Application.Products.Prices.AddPrice;
+
+/// <summary>
+/// PRD-003 — Comando para registrar un nuevo precio histórico para un Product.
+/// Price debe ser > 0. PriceValidFrom debe ser >= hoy_AR (Cat2, TimeProvider).
+/// </summary>
+public sealed record AddProductPriceCommand(
+    int ProductId,
+    decimal Price,
+    DateOnly PriceValidFrom);

src/api/SIGCM2.Application/Products/Prices/AddPrice/AddProductPriceCommandHandler.cs

@@ -0,0 +1,89 @@
+using System.Transactions;
+using SIGCM2.Application.Abstractions;
+using SIGCM2.Application.Abstractions.Persistence;
+using SIGCM2.Application.Audit;
+using SIGCM2.Domain.Entities;
+using SIGCM2.Domain.Exceptions;
+
+namespace SIGCM2.Application.Products.Prices.AddPrice;
+
+/// <summary>
+/// PRD-003 — Handler del comando AddProductPrice.
+/// Flujo: verifica producto activo → abre TransactionScope (AsyncFlow) →
+///        AddAsync (SP usp_AddProductPrice) → IAuditLogger.LogAsync (fail-closed) →
+///        tx.Complete() → construye response con GetByProductIdAsync.
+/// </summary>
+public sealed class AddProductPriceCommandHandler
+    : ICommandHandler<AddProductPriceCommand, AddProductPriceResponse>
+{
+    private readonly IProductPriceRepository _pricesRepo;
+    private readonly IProductRepository _productsRepo;
+    private readonly IAuditLogger _audit;
+    private readonly TimeProvider _timeProvider;
+
+    public AddProductPriceCommandHandler(
+        IProductPriceRepository pricesRepo,
+        IProductRepository productsRepo,
+        IAuditLogger audit,
+        TimeProvider timeProvider)
+    {
+        _pricesRepo = pricesRepo;
+        _productsRepo = productsRepo;
+        _audit = audit;
+        _timeProvider = timeProvider;
+    }
+
+    public async Task<AddProductPriceResponse> Handle(AddProductPriceCommand command)
+    {
+        // 1. Producto debe existir Y estar activo (defensa Application — el SP también valida en BD).
+        var product = await _productsRepo.GetByIdAsync(command.ProductId)
+            ?? throw new ProductNotFoundException(command.ProductId);
+
+        if (!product.IsActive)
+            throw new ProductNotFoundException(command.ProductId); // inactivo = invisible para clientes
+
+        // 2. TX + SP + audit (fail-closed).
+        //    El audit.LogAsync enlista en el mismo TransactionScope — si falla, rollback total.
+        //    GetByProductIdAsync se ejecuta FUERA del scope (post-commit) para evitar
+        //    "TransactionScope is already complete" al abrir una nueva conexión dentro del using.
+        long newId;
+        long? closedId;
+        using (var tx = new TransactionScope(
+            TransactionScopeOption.Required,
+            new TransactionOptions { IsolationLevel = System.Transactions.IsolationLevel.ReadCommitted },
+            TransactionScopeAsyncFlowOption.Enabled))
+        {
+            (newId, closedId) = await _pricesRepo.AddAsync(
+                command.ProductId, command.Price, command.PriceValidFrom);
+
+            await _audit.LogAsync(
+                action: "product_price.created",
+                targetType: "ProductPrice",
+                targetId: newId.ToString(),
+                metadata: new
+                {
+                    after = new
+                    {
+                        command.ProductId,
+                        command.Price,
+                        priceValidFrom = command.PriceValidFrom.ToString("yyyy-MM-dd"),
+                    },
+                    closedPriceId = closedId
+                });
+
+            tx.Complete();
+        } // TX disposed (committed) here — BEFORE the post-commit read below.
+
+        // 3. Compongo la respuesta post-commit con lectura de historial actualizado.
+        var prices = await _pricesRepo.GetByProductIdAsync(command.ProductId);
+        var created = prices.Single(p => p.Id == newId);
+        var closed  = closedId.HasValue
+            ? prices.SingleOrDefault(p => p.Id == closedId.Value)
+            : null;
+
+        return new AddProductPriceResponse(ToDto(created), closed is null ? null : ToDto(closed));
+    }
+
+    private static ProductPriceDto ToDto(ProductPrice p)
+        => new(p.Id, p.ProductId, p.Price, p.PriceValidFrom, p.PriceValidTo, p.IsActive);
+}

src/api/SIGCM2.Application/Products/Prices/AddPrice/AddProductPriceCommandValidator.cs

@@ -0,0 +1,29 @@
+using FluentValidation;
+using SIGCM2.Application.Common;
+
+namespace SIGCM2.Application.Products.Prices.AddPrice;
+
+/// <summary>
+/// PRD-003 — FluentValidation validator para AddProductPriceCommand.
+/// Inyecta TimeProvider para obtener hoy_AR (Cat2, nunca DateTime.Now).
+/// FakeTimeProvider en tests garantiza determinismo.
+/// </summary>
+public sealed class AddProductPriceCommandValidator : AbstractValidator<AddProductPriceCommand>
+{
+    public AddProductPriceCommandValidator(TimeProvider timeProvider)
+    {
+        var today = timeProvider.GetArgentinaToday();
+
+        RuleFor(x => x.ProductId)
+            .GreaterThan(0)
+            .WithMessage("ProductId debe ser un entero positivo.");
+
+        RuleFor(x => x.Price)
+            .GreaterThan(0m)
+            .WithMessage("El precio debe ser mayor a cero.");
+
+        RuleFor(x => x.PriceValidFrom)
+            .GreaterThanOrEqualTo(today)
+            .WithMessage($"PriceValidFrom debe ser >= hoy ({today:yyyy-MM-dd} ART). No se permiten precios con fecha retroactiva.");
+    }
+}

src/api/SIGCM2.Application/Products/Prices/AddPrice/AddProductPriceResponse.cs

@@ -0,0 +1,9 @@
+namespace SIGCM2.Application.Products.Prices.AddPrice;
+
+/// <summary>
+/// PRD-003 — Respuesta del comando AddProductPrice.
+/// Closed es null si era el primer precio registrado para el producto.
+/// </summary>
+public sealed record AddProductPriceResponse(
+    ProductPriceDto Created,
+    ProductPriceDto? Closed);

src/api/SIGCM2.Application/Products/Prices/GetHistory/GetProductPricesQuery.cs

@@ -0,0 +1,8 @@
+namespace SIGCM2.Application.Products.Prices.GetHistory;
+
+/// <summary>
+/// PRD-003 — Query para obtener el historial de precios de un Product.
+/// Devuelve lista ordenada descending por PriceValidFrom (activo primero).
+/// Lanza ProductNotFoundException si el producto no existe.
+/// </summary>
+public sealed record GetProductPricesQuery(int ProductId);

src/api/SIGCM2.Application/Products/Prices/GetHistory/GetProductPricesQueryHandler.cs

@@ -0,0 +1,42 @@
+using SIGCM2.Application.Abstractions;
+using SIGCM2.Application.Abstractions.Persistence;
+using SIGCM2.Application.Products.Prices;
+using SIGCM2.Domain.Exceptions;
+
+namespace SIGCM2.Application.Products.Prices.GetHistory;
+
+/// <summary>
+/// PRD-003 — Handler de GetProductPricesQuery.
+/// Verifica que el producto exista (404 si no), luego retorna historial de precios
+/// ordenado descending por PriceValidFrom (responsabilidad del repo — SQL ORDER BY).
+/// Lista vacía es válida (nuevo producto sin precios registrados aún).
+/// </summary>
+public sealed class GetProductPricesQueryHandler
+    : ICommandHandler<GetProductPricesQuery, IReadOnlyList<ProductPriceDto>>
+{
+    private readonly IProductPriceRepository _pricesRepo;
+    private readonly IProductRepository _productsRepo;
+
+    public GetProductPricesQueryHandler(
+        IProductPriceRepository pricesRepo,
+        IProductRepository productsRepo)
+    {
+        _pricesRepo = pricesRepo;
+        _productsRepo = productsRepo;
+    }
+
+    public async Task<IReadOnlyList<ProductPriceDto>> Handle(GetProductPricesQuery query)
+    {
+        // Verifica existencia del producto (lanza 404 si no existe).
+        _ = await _productsRepo.GetByIdAsync(query.ProductId)
+            ?? throw new ProductNotFoundException(query.ProductId);
+
+        var prices = await _pricesRepo.GetByProductIdAsync(query.ProductId);
+
+        return prices
+            .Select(p => new ProductPriceDto(
+                p.Id, p.ProductId, p.Price,
+                p.PriceValidFrom, p.PriceValidTo, p.IsActive))
+            .ToList();
+    }
+}

src/api/SIGCM2.Application/Products/Prices/ProductPriceDto.cs

@@ -0,0 +1,13 @@
+namespace SIGCM2.Application.Products.Prices;
+
+/// <summary>
+/// PRD-003 — DTO de lectura para un registro de precio histórico de Product.
+/// IsActive = true cuando PriceValidTo is null (precio vigente en curso).
+/// </summary>
+public sealed record ProductPriceDto(
+    long Id,
+    int ProductId,
+    decimal Price,
+    DateOnly PriceValidFrom,
+    DateOnly? PriceValidTo,
+    bool IsActive);

src/api/SIGCM2.Application/Products/Pricing/IProductPricingService.cs

@@ -0,0 +1,18 @@
+namespace SIGCM2.Application.Products.Pricing;
+
+/// <summary>
+/// PRD-003 — Servicio de consulta de precio vigente de un Product para una fecha civil (Cat2).
+/// Contrato forward para PRC-001 (tasación).
+///
+/// Retorna null si no existe historial de precios para el producto en la fecha indicada.
+/// La política de fallback (usar Product.BasePrice o lanzar ProductSinPrecioActivoException)
+/// queda en el consumidor (OQ-B: Product.BasePrice es ortogonal a ProductPrices).
+/// </summary>
+public interface IProductPricingService
+{
+    /// <summary>
+    /// Devuelve el precio cuya ventana [PriceValidFrom, PriceValidTo] cubre la fecha civil dada,
+    /// o null si ningún registro de precio cubre esa fecha.
+    /// </summary>
+    Task<decimal?> GetPriceAtAsync(int productId, DateOnly date, CancellationToken ct = default);
+}

src/api/SIGCM2.Application/Products/Pricing/ProductPricingService.cs

@@ -0,0 +1,24 @@
+using SIGCM2.Application.Abstractions.Persistence;
+
+namespace SIGCM2.Application.Products.Pricing;
+
+/// <summary>
+/// PRD-003 — Implementación de IProductPricingService.
+/// Delega en IProductPriceRepository.GetActiveAsync para el lookup de ventana civil.
+/// </summary>
+public sealed class ProductPricingService : IProductPricingService
+{
+    private readonly IProductPriceRepository _repo;
+
+    public ProductPricingService(IProductPriceRepository repo)
+    {
+        _repo = repo;
+    }
+
+    /// <inheritdoc />
+    public async Task<decimal?> GetPriceAtAsync(int productId, DateOnly date, CancellationToken ct = default)
+    {
+        var price = await _repo.GetActiveAsync(productId, date, ct);
+        return price?.Price;
+    }
+}

src/api/SIGCM2.Domain/Entities/ProductPrice.cs

@@ -0,0 +1,25 @@
+namespace SIGCM2.Domain.Entities;
+
+/// <summary>
+/// PRD-003 — Immutable record representing a price snapshot for a Product.
+/// Business dates are Cat2 (civil Argentina dates, DateOnly). Forward-only — no mutations.
+/// PriceValidTo = null means the row is the currently active price.
+/// </summary>
+public sealed record ProductPrice(
+    long Id,
+    int ProductId,
+    decimal Price,
+    DateOnly PriceValidFrom,
+    DateOnly? PriceValidTo,
+    DateTime FechaCreacion)
+{
+    /// <summary>True if this row is the currently active price (PriceValidTo is null).</summary>
+    public bool IsActive => PriceValidTo is null;
+
+    /// <summary>
+    /// True if this price's window covers the given civil date (inclusive on both ends).
+    /// An active row (PriceValidTo = null) covers any date on or after PriceValidFrom.
+    /// </summary>
+    public bool CoversDate(DateOnly date)
+        => PriceValidFrom <= date && (PriceValidTo is null || PriceValidTo >= date);
+}

src/api/SIGCM2.Domain/Exceptions/ProductPriceForwardOnlyException.cs

@@ -0,0 +1,23 @@
+namespace SIGCM2.Domain.Exceptions;
+
+/// <summary>
+/// Thrown when attempting to add a ProductPrice with a PriceValidFrom that is not strictly
+/// greater than the currently active price's PriceValidFrom. → HTTP 409
+/// </summary>
+public sealed class ProductPriceForwardOnlyException : DomainException
+{
+    public int ProductId { get; }
+    public DateOnly NewPriceValidFrom { get; }
+    public DateOnly ActivePriceValidFrom { get; }
+
+    public ProductPriceForwardOnlyException(
+        int productId,
+        DateOnly newPriceValidFrom,
+        DateOnly activePriceValidFrom)
+        : base($"El nuevo PriceValidFrom ({newPriceValidFrom:yyyy-MM-dd}) debe ser estrictamente mayor al PriceValidFrom del precio activo ({activePriceValidFrom:yyyy-MM-dd}).")
+    {
+        ProductId = productId;
+        NewPriceValidFrom = newPriceValidFrom;
+        ActivePriceValidFrom = activePriceValidFrom;
+    }
+}

src/api/SIGCM2.Domain/Exceptions/ProductPriceInvalidException.cs

@@ -0,0 +1,19 @@
+namespace SIGCM2.Domain.Exceptions;
+
+/// <summary>
+/// Thrown when a ProductPrice value fails domain business validation
+/// (e.g., Price &lt;= 0, PriceValidFrom in the past). → HTTP 400
+/// Used as defense-in-depth alongside FluentValidation in the Application layer.
+/// </summary>
+public sealed class ProductPriceInvalidException : DomainException
+{
+    public string Field { get; }
+    public string Reason { get; }
+
+    public ProductPriceInvalidException(string field, string reason)
+        : base($"Valor inválido para {field}: {reason}")
+    {
+        Field = field;
+        Reason = reason;
+    }
+}

src/api/SIGCM2.Domain/Exceptions/ProductSinPrecioActivoException.cs

@@ -0,0 +1,18 @@
+namespace SIGCM2.Domain.Exceptions;
+
+/// <summary>
+/// Thrown when no ProductPrice row covers the requested date for the given product. → HTTP 404
+/// Consumers of IProductPricingService may throw this when GetPriceAtAsync returns null.
+/// </summary>
+public sealed class ProductSinPrecioActivoException : DomainException
+{
+    public int ProductId { get; }
+    public DateOnly Date { get; }
+
+    public ProductSinPrecioActivoException(int productId, DateOnly date)
+        : base($"No existe precio registrado para el producto {productId} aplicable a la fecha {date:yyyy-MM-dd}.")
+    {
+        ProductId = productId;
+        Date = date;
+    }
+}

src/api/SIGCM2.Infrastructure/DependencyInjection.cs

@@ -43,6 +43,8 @@ public static class DependencyInjection
         services.AddScoped<IProductRepository, ProductRepository>();
         // PRD-002: replaces NullProductQueryRepository from Application DI
         services.AddScoped<IProductQueryRepository, ProductQueryRepository>();
+        // PRD-003: ProductPrices históricos
+        services.AddScoped<IProductPriceRepository, ProductPriceRepository>();
 
         // JWT Options — bound lazily via IOptions so tests can override via ConfigureWebHost
         services.Configure<JwtOptions>(configuration.GetSection("Jwt"));

src/api/SIGCM2.Infrastructure/Persistence/ProductPriceRepository.cs

@@ -0,0 +1,144 @@
+using System.Data;
+using Dapper;
+using Microsoft.Data.SqlClient;
+using SIGCM2.Application.Abstractions.Persistence;
+using SIGCM2.Domain.Entities;
+using SIGCM2.Domain.Exceptions;
+
+namespace SIGCM2.Infrastructure.Persistence;
+
+/// <summary>
+/// PRD-003 — Dapper implementation of IProductPriceRepository against dbo.ProductPrices.
+/// AddAsync invokes dbo.usp_AddProductPrice and maps SqlException numbers to domain exceptions.
+/// GetByProductIdAsync and GetActiveAsync run direct SQL and map DateTime columns to DateOnly.
+/// </summary>
+public sealed class ProductPriceRepository : IProductPriceRepository
+{
+    private readonly SqlConnectionFactory _factory;
+
+    public ProductPriceRepository(SqlConnectionFactory factory)
+    {
+        _factory = factory;
+    }
+
+    /// <inheritdoc/>
+    public async Task<(long NewId, long? ClosedId)> AddAsync(
+        int productId,
+        decimal price,
+        DateOnly priceValidFrom,
+        CancellationToken ct = default)
+    {
+        var p = new DynamicParameters();
+        p.Add("@ProductId",      productId,                                        DbType.Int32);
+        p.Add("@Price",          price,                                            DbType.Decimal, precision: 12, scale: 2);
+        p.Add("@PriceValidFrom", priceValidFrom.ToDateTime(TimeOnly.MinValue),     DbType.Date);
+        p.Add("@NewId",          dbType: DbType.Int64, direction: ParameterDirection.Output);
+        p.Add("@ClosedId",       dbType: DbType.Int64, direction: ParameterDirection.Output);
+
+        await using var connection = _factory.CreateConnection();
+        await connection.OpenAsync(ct);
+
+        try
+        {
+            await connection.ExecuteAsync(
+                new CommandDefinition(
+                    "dbo.usp_AddProductPrice",
+                    p,
+                    commandType: CommandType.StoredProcedure,
+                    cancellationToken: ct));
+        }
+        catch (SqlException ex) when (ex.Number == 50404)
+        {
+            throw new ProductNotFoundException(productId);
+        }
+        catch (SqlException ex) when (ex.Number == 50409)
+        {
+            // Forward-only violation detected by SP (new PVF <= active PVF).
+            // activePriceValidFrom is not returned by the SP; use MinValue as safe placeholder.
+            throw new ProductPriceForwardOnlyException(productId, priceValidFrom, DateOnly.MinValue);
+        }
+        catch (SqlException ex) when (ex.Number == 2601 || ex.Number == 2627)
+        {
+            // Race condition: two concurrent inserts with PriceValidTo IS NULL slipped through
+            // the SERIALIZABLE guard. Defense-in-depth: surface as forward-only.
+            throw new ProductPriceForwardOnlyException(productId, priceValidFrom, DateOnly.MinValue);
+        }
+
+        var newId    = p.Get<long>("@NewId");
+        var closedId = p.Get<long?>("@ClosedId");
+        return (newId, closedId);
+    }
+
+    /// <inheritdoc/>
+    public async Task<IReadOnlyList<ProductPrice>> GetByProductIdAsync(
+        int productId,
+        CancellationToken ct = default)
+    {
+        // Uses IX_ProductPrices_Lookup (ProductId, PriceValidFrom DESC).
+        const string sql = """
+            SELECT Id, ProductId, Price, PriceValidFrom, PriceValidTo, FechaCreacion
+            FROM dbo.ProductPrices
+            WHERE ProductId = @ProductId
+            ORDER BY PriceValidFrom DESC, Id DESC
+            """;
+
+        await using var connection = _factory.CreateConnection();
+        await connection.OpenAsync(ct);
+
+        var rows = await connection.QueryAsync<ProductPriceRow>(
+            new CommandDefinition(sql, new { ProductId = productId }, cancellationToken: ct));
+
+        return rows.Select(MapRow).ToList();
+    }
+
+    /// <inheritdoc/>
+    public async Task<ProductPrice?> GetActiveAsync(
+        int productId,
+        DateOnly date,
+        CancellationToken ct = default)
+    {
+        // Uses IX_ProductPrices_Lookup (ProductId, PriceValidFrom DESC) INCLUDE(Price, PriceValidTo).
+        // TOP 1 ordered DESC by PriceValidFrom returns the most-recent row whose window covers date.
+        const string sql = """
+            SELECT TOP 1 Id, ProductId, Price, PriceValidFrom, PriceValidTo, FechaCreacion
+            FROM dbo.ProductPrices
+            WHERE ProductId = @ProductId
+              AND PriceValidFrom <= @Date
+              AND (PriceValidTo IS NULL OR PriceValidTo >= @Date)
+            ORDER BY PriceValidFrom DESC, Id DESC
+            """;
+
+        await using var connection = _factory.CreateConnection();
+        await connection.OpenAsync(ct);
+
+        var row = await connection.QuerySingleOrDefaultAsync<ProductPriceRow>(
+            new CommandDefinition(
+                sql,
+                new { ProductId = productId, Date = date.ToDateTime(TimeOnly.MinValue) },
+                cancellationToken: ct));
+
+        return row is null ? null : MapRow(row);
+    }
+
+    // ── Mapping ───────────────────────────────────────────────────────────────
+    // Dapper maps SQL DATE columns to DateTime; we convert to DateOnly here.
+
+    private static ProductPrice MapRow(ProductPriceRow r)
+        => new(
+            Id:             r.Id,
+            ProductId:      r.ProductId,
+            Price:          r.Price,
+            PriceValidFrom: DateOnly.FromDateTime(r.PriceValidFrom),
+            PriceValidTo:   r.PriceValidTo.HasValue
+                                ? DateOnly.FromDateTime(r.PriceValidTo.Value)
+                                : (DateOnly?)null,
+            FechaCreacion:  r.FechaCreacion);
+
+    private sealed record ProductPriceRow(
+        long      Id,
+        int       ProductId,
+        decimal   Price,
+        DateTime  PriceValidFrom,
+        DateTime? PriceValidTo,
+        DateTime  FechaCreacion);
+}

src/web/src/features/products/api/addProductPrice.ts

@@ -0,0 +1,13 @@
+import { axiosClient } from '@/api/axiosClient'
+import type { AddProductPriceRequest, AddProductPriceResponse } from '../types'
+
+export async function addProductPrice(
+  productId: number,
+  payload: AddProductPriceRequest,
+): Promise<AddProductPriceResponse> {
+  const res = await axiosClient.post<AddProductPriceResponse>(
+    `/api/v1/admin/products/${productId}/prices`,
+    payload,
+  )
+  return res.data
+}

src/web/src/features/products/api/getProductPrices.ts

@@ -0,0 +1,7 @@
+import { axiosClient } from '@/api/axiosClient'
+import type { ProductPrice } from '../types'
+
+export async function getProductPrices(productId: number): Promise<ProductPrice[]> {
+  const res = await axiosClient.get<ProductPrice[]>(`/api/v1/products/${productId}/prices`)
+  return res.data
+}

src/web/src/features/products/components/AddProductPriceDialog.tsx

@@ -0,0 +1,206 @@
+import { useEffect } from 'react'
+import { useForm } from 'react-hook-form'
+import { zodResolver } from '@hookform/resolvers/zod'
+import { z } from 'zod'
+import { isAxiosError } from 'axios'
+import { AlertCircle } from 'lucide-react'
+import { Alert, AlertDescription } from '@/components/ui/alert'
+import { Button } from '@/components/ui/button'
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from '@/components/ui/dialog'
+import {
+  Form,
+  FormControl,
+  FormField,
+  FormItem,
+  FormLabel,
+  FormMessage,
+} from '@/components/ui/form'
+import { Input } from '@/components/ui/input'
+import { todayArgentina } from '@/lib/dateFormat'
+import { useAddProductPrice } from '../hooks/useAddProductPrice'
+
+// ─── Schema (Zod, espejo del backend) ────────────────────────────────────────
+
+const addPriceSchema = z.object({
+  price: z.coerce
+    .number('Debe ser un número')
+    .positive('El precio debe ser mayor a cero.'),
+  priceValidFrom: z
+    .string()
+    .min(1, 'La fecha es requerida.')
+    .regex(/^\d{4}-\d{2}-\d{2}$/, 'Formato yyyy-MM-dd requerido.')
+    .refine(
+      (v) => v >= todayArgentina(),
+      'La fecha no puede ser anterior a hoy.',
+    ),
+})
+
+type AddPriceFormRaw = {
+  price: string
+  priceValidFrom: string
+}
+
+type AddPriceFormOutput = z.infer<typeof addPriceSchema>
+
+// ─── Error resolver ────────────────────────────────────────────────────────────
+
+function resolveBackendError(err: unknown): string | null {
+  if (!err) return null
+  if (isAxiosError(err) && err.response?.data) {
+    const data = err.response.data as { error?: string; message?: string }
+    if (err.response.status === 409) {
+      return data.message ?? 'La fecha debe ser posterior al precio vigente.'
+    }
+    if (err.response.status === 404) {
+      return data.message ?? 'Producto no encontrado.'
+    }
+    return data.message ?? data.error ?? 'Error al guardar el precio.'
+  }
+  return 'Error al guardar el precio. Intentá de nuevo.'
+}
+
+// ─── Props ────────────────────────────────────────────────────────────────────
+
+interface AddProductPriceDialogProps {
+  open: boolean
+  onOpenChange: (open: boolean) => void
+  productId: number
+}
+
+// ─── Component ────────────────────────────────────────────────────────────────
+
+export function AddProductPriceDialog({
+  open,
+  onOpenChange,
+  productId,
+}: AddProductPriceDialogProps) {
+  const mutation = useAddProductPrice(productId)
+
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  const form = useForm<AddPriceFormRaw>({
+    resolver: zodResolver(addPriceSchema) as any,
+    defaultValues: {
+      price: '',
+      priceValidFrom: '',
+    },
+    mode: 'onSubmit',
+  })
+
+  // Reset form and mutation state when dialog opens
+  useEffect(() => {
+    if (open) {
+      form.reset({ price: '', priceValidFrom: '' })
+      mutation.reset()
+    }
+  }, [open]) // eslint-disable-line react-hooks/exhaustive-deps
+
+  const backendError = resolveBackendError(mutation.error)
+  const today = todayArgentina()
+
+  function handleSubmit(values: AddPriceFormOutput) {
+    mutation.mutate(
+      { price: values.price, priceValidFrom: values.priceValidFrom },
+      {
+        onSuccess: () => {
+          onOpenChange(false)
+        },
+      },
+    )
+  }
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent className="sm:max-w-md">
+        <DialogHeader>
+          <DialogTitle>Programar nuevo precio</DialogTitle>
+          <DialogDescription>
+            Ingresá el nuevo precio y la fecha desde la que estará vigente. El
+            precio actual quedará cerrado.
+          </DialogDescription>
+        </DialogHeader>
+
+        <Form {...form}>
+          <form
+            onSubmit={form.handleSubmit(
+              handleSubmit as unknown as Parameters<typeof form.handleSubmit>[0],
+            )}
+            className="space-y-4"
+            noValidate
+          >
+            {backendError && (
+              <Alert variant="destructive">
+                <AlertCircle className="h-4 w-4" />
+                <AlertDescription>{backendError}</AlertDescription>
+              </Alert>
+            )}
+
+            {/* Precio */}
+            <FormField
+              control={form.control}
+              name="price"
+              render={({ field }) => (
+                <FormItem>
+                  <FormLabel>Precio</FormLabel>
+                  <FormControl>
+                    <Input
+                      {...field}
+                      type="number"
+                      step="0.01"
+                      min="0.01"
+                      placeholder="0.00"
+                      aria-label="Precio"
+                      disabled={mutation.isPending}
+                    />
+                  </FormControl>
+                  <FormMessage />
+                </FormItem>
+              )}
+            />
+
+            {/* Vigente desde */}
+            <FormField
+              control={form.control}
+              name="priceValidFrom"
+              render={({ field }) => (
+                <FormItem>
+                  <FormLabel>Vigente desde</FormLabel>
+                  <FormControl>
+                    <Input
+                      {...field}
+                      type="date"
+                      min={today}
+                      aria-label="Vigente desde"
+                      disabled={mutation.isPending}
+                    />
+                  </FormControl>
+                  <FormMessage />
+                </FormItem>
+              )}
+            />
+
+            <DialogFooter className="gap-2">
+              <Button
+                type="button"
+                variant="ghost"
+                onClick={() => onOpenChange(false)}
+                disabled={mutation.isPending}
+              >
+                Cancelar
+              </Button>
+              <Button type="submit" disabled={mutation.isPending}>
+                {mutation.isPending ? 'Guardando...' : 'Guardar'}
+              </Button>
+            </DialogFooter>
+          </form>
+        </Form>
+      </DialogContent>
+    </Dialog>
+  )
+}

src/web/src/features/products/components/ProductPriceHistory.tsx

@@ -0,0 +1,114 @@
+import { useState } from 'react'
+import { AlertCircle, Plus } from 'lucide-react'
+import { Alert, AlertDescription } from '@/components/ui/alert'
+import { Badge } from '@/components/ui/badge'
+import { Button } from '@/components/ui/button'
+import { Skeleton } from '@/components/ui/skeleton'
+import {
+  Table,
+  TableBody,
+  TableCell,
+  TableHead,
+  TableHeader,
+  TableRow,
+} from '@/components/ui/table'
+import { CanPerform } from '@/components/auth/CanPerform'
+import { formatCivilDate } from '@/lib/dateFormat'
+import { formatCurrency } from '@/lib/numberFormat'
+import { useProductPrices } from '../hooks/useProductPrices'
+import { AddProductPriceDialog } from './AddProductPriceDialog'
+
+// ─── Props ────────────────────────────────────────────────────────────────────
+
+interface ProductPriceHistoryProps {
+  productId: number
+}
+
+// ─── Component ────────────────────────────────────────────────────────────────
+
+export function ProductPriceHistory({ productId }: ProductPriceHistoryProps) {
+  const [addOpen, setAddOpen] = useState(false)
+  const { data: prices, isLoading, isError } = useProductPrices(productId)
+
+  if (isLoading) {
+    return (
+      <div className="space-y-2">
+        <Skeleton className="h-8 w-full" />
+        <Skeleton className="h-8 w-full" />
+        <Skeleton className="h-8 w-full" />
+      </div>
+    )
+  }
+
+  if (isError) {
+    return (
+      <Alert variant="destructive">
+        <AlertCircle className="h-4 w-4" />
+        <AlertDescription>Error al cargar precios del producto.</AlertDescription>
+      </Alert>
+    )
+  }
+
+  const isEmpty = !prices?.length
+
+  return (
+    <div className="space-y-3">
+      <div className="flex items-center justify-between">
+        <h2 className="text-lg font-semibold">Historial de precios</h2>
+        <CanPerform permission="catalogo:productos:gestionar">
+          <Button size="sm" variant="outline" onClick={() => setAddOpen(true)}>
+            <Plus className="mr-2 h-4 w-4" />
+            Programar nuevo precio
+          </Button>
+        </CanPerform>
+      </div>
+
+      {isEmpty ? (
+        <div className="flex flex-col items-center gap-3 py-12 text-center text-muted-foreground">
+          <p>Sin historial de precios. Este producto no tiene precios registrados.</p>
+          <CanPerform permission="catalogo:productos:gestionar">
+            <Button variant="outline" size="sm" onClick={() => setAddOpen(true)}>
+              <Plus className="mr-2 h-4 w-4" />
+              Programar nuevo precio
+            </Button>
+          </CanPerform>
+        </div>
+      ) : (
+        <div className="rounded-md border">
+          <Table>
+            <TableHeader>
+              <TableRow>
+                <TableHead>Desde</TableHead>
+                <TableHead>Hasta</TableHead>
+                <TableHead>Precio</TableHead>
+                <TableHead>Estado</TableHead>
+              </TableRow>
+            </TableHeader>
+            <TableBody>
+              {prices.map((p) => (
+                <TableRow key={p.id}>
+                  <TableCell>{formatCivilDate(p.priceValidFrom)}</TableCell>
+                  <TableCell>
+                    {p.priceValidTo ? formatCivilDate(p.priceValidTo) : '—'}
+                  </TableCell>
+                  <TableCell>{formatCurrency(p.price)}</TableCell>
+                  <TableCell>
+                    {p.isActive ? (
+                      <Badge variant="default">Vigente</Badge>
+                    ) : null}
+                  </TableCell>
+                </TableRow>
+              ))}
+            </TableBody>
+          </Table>
+        </div>
+      )}
+
+      <AddProductPriceDialog
+        open={addOpen}
+        onOpenChange={setAddOpen}
+        productId={productId}
+      />
+    </div>
+  )
+}

src/web/src/features/products/hooks/useAddProductPrice.ts

@@ -0,0 +1,13 @@
+import { useMutation, useQueryClient } from '@tanstack/react-query'
+import { addProductPrice } from '../api/addProductPrice'
+import type { AddProductPriceRequest } from '../types'
+
+export function useAddProductPrice(productId: number) {
+  const queryClient = useQueryClient()
+  return useMutation({
+    mutationFn: (payload: AddProductPriceRequest) => addProductPrice(productId, payload),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['products', productId, 'prices'] })
+    },
+  })
+}

src/web/src/features/products/hooks/useProductPrices.ts

@@ -0,0 +1,11 @@
+import { useQuery } from '@tanstack/react-query'
+import { getProductPrices } from '../api/getProductPrices'
+
+export function useProductPrices(productId: number) {
+  return useQuery({
+    queryKey: ['products', productId, 'prices'],
+    queryFn: () => getProductPrices(productId),
+    enabled: productId > 0,
+    staleTime: 30_000,
+  })
+}

src/web/src/features/products/index.ts

@@ -6,4 +6,7 @@ export type {
   UpdateProductRequest,
   PagedResult,
   ListProductsParams,
+  ProductPrice,
+  AddProductPriceRequest,
+  AddProductPriceResponse,
 } from './types'

src/web/src/features/products/pages/ProductsPage.tsx

@@ -5,11 +5,18 @@ import { Button } from '@/components/ui/button'
 import { Input } from '@/components/ui/input'
 import { Skeleton } from '@/components/ui/skeleton'
 import { Alert, AlertDescription } from '@/components/ui/alert'
+import {
+  Dialog,
+  DialogContent,
+  DialogHeader,
+  DialogTitle,
+} from '@/components/ui/dialog'
 import { CanPerform } from '@/components/auth/CanPerform'
 import { useProducts } from '../hooks/useProducts'
 import { useDeactivateProduct } from '../hooks/useDeactivateProduct'
 import { ProductFormDialog } from '../components/ProductFormDialog'
 import { DeactivateProductDialog } from '../components/DeactivateProductDialog'
+import { ProductPriceHistory } from '../components/ProductPriceHistory'
 import type { ProductListItem, ProductDetail } from '../types'
 
 const PAGE_SIZE = 20
@@ -26,6 +33,11 @@ export function ProductsPage() {
   const [deactivateOpen, setDeactivateOpen] = useState(false)
   const [deactivatingProduct, setDeactivatingProduct] = useState<ProductListItem | null>(null)
 
+  // ── Prices dialog state (PRD-003) ────────────────────────────────────────
+  const [pricesOpen, setPricesOpen] = useState(false)
+  const [pricesProductId, setPricesProductId] = useState<number | null>(null)
+  const [pricesProductName, setPricesProductName] = useState<string>('')
+
   // ── Pagination & filter state ────────────────────────────────────────────
   const [page, setPage] = useState(1)
   const [medioIdFilter, setMedioIdFilter] = useState<number | undefined>(undefined)
@@ -59,6 +71,12 @@ export function ProductsPage() {
     setDeactivateOpen(true)
   }
 
+  function openPrices(p: ProductListItem) {
+    setPricesProductId(p.id)
+    setPricesProductName(p.nombre)
+    setPricesOpen(true)
+  }
+
   async function handleDeactivate(id: number) {
     await deactivateProduct(id)
     toast.success('Producto desactivado')
@@ -153,8 +171,16 @@ export function ProductsPage() {
                     </span>
                   </td>
                   <td className="px-4 py-2">
-                    <CanPerform permission="catalogo:productos:gestionar">
+                    <div className="flex gap-1">
-                      <div className="flex gap-1">
+                      <Button
+                        variant="ghost"
+                        size="sm"
+                        onClick={() => openPrices(p)}
+                        aria-label={`Ver precios de ${p.nombre}`}
+                      >
+                        Ver precios
+                      </Button>
+                      <CanPerform permission="catalogo:productos:gestionar">
                         <Button
                           variant="ghost"
                           size="sm"
@@ -170,8 +196,8 @@ export function ProductsPage() {
                         >
                           Desactivar
                         </Button>
-                      </div>
+                      </CanPerform>
-                    </CanPerform>
+                    </div>
                   </td>
                 </tr>
               ))}
@@ -231,6 +257,18 @@ export function ProductsPage() {
           onConfirm={handleDeactivate}
         />
       )}
+
+      {/* Prices history dialog (PRD-003) */}
+      {pricesProductId !== null && (
+        <Dialog open={pricesOpen} onOpenChange={setPricesOpen}>
+          <DialogContent className="sm:max-w-2xl">
+            <DialogHeader>
+              <DialogTitle>Precios — {pricesProductName}</DialogTitle>
+            </DialogHeader>
+            <ProductPriceHistory productId={pricesProductId} />
+          </DialogContent>
+        </Dialog>
+      )}
     </div>
   )
 }

src/web/src/features/products/types.ts

@@ -56,3 +56,24 @@ export interface ListProductsParams {
   productTypeId?: number
   rubroId?: number
 }
+
+// PRD-003 — ProductPrices históricos
+
+export interface ProductPrice {
+  id: number
+  productId: number
+  price: number
+  priceValidFrom: string   // "yyyy-MM-dd" (Cat2)
+  priceValidTo: string | null
+  isActive: boolean
+}
+
+export interface AddProductPriceRequest {
+  price: number
+  priceValidFrom: string   // "yyyy-MM-dd"
+}
+
+export interface AddProductPriceResponse {
+  created: ProductPrice
+  closed: ProductPrice | null
+}

src/web/src/lib/numberFormat.ts

@@ -0,0 +1,17 @@
+/**
+ * Formateo de números — utility centralizada.
+ * Usar SIEMPRE estas funciones en lugar de Intl.NumberFormat inline.
+ */
+
+/**
+ * Formatea un número como moneda ARS (pesos argentinos).
+ * Output: "$ 1.500,50" o similar según locale.
+ */
+export function formatCurrency(amount: number): string {
+  return new Intl.NumberFormat('es-AR', {
+    style: 'currency',
+    currency: 'ARS',
+    minimumFractionDigits: 2,
+    maximumFractionDigits: 2,
+  }).format(amount)
+}

src/web/src/tests/features/products/AddProductPriceDialog.test.tsx

@@ -0,0 +1,253 @@
+import { describe, it, expect, beforeAll, afterAll, afterEach, vi, beforeEach } from 'vitest'
+import { render, screen, waitFor } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import { http, HttpResponse } from 'msw'
+import { setupServer } from 'msw/node'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import React from 'react'
+import { AddProductPriceDialog } from '../../../features/products/components/AddProductPriceDialog'
+import type { AddProductPriceResponse } from '../../../features/products/types'
+
+const API_URL = 'http://localhost:5000'
+
+vi.mock('sonner', () => ({
+  toast: { success: vi.fn(), error: vi.fn() },
+}))
+
+// ─── Server ───────────────────────────────────────────────────────────────────
+
+const server = setupServer()
+
+beforeAll(() => server.listen({ onUnhandledRequest: 'error' }))
+afterEach(() => {
+  server.resetHandlers()
+  vi.clearAllMocks()
+  vi.useRealTimers()
+})
+afterAll(() => server.close())
+
+// ─── Fake timers helper ───────────────────────────────────────────────────────
+// Fix "today" to 2026-04-19 ART (UTC-3).
+// 2026-04-19T12:00:00-03:00 = 2026-04-19T15:00:00Z
+// todayArgentina() uses Intl.DateTimeFormat with timeZone so this is stable.
+
+function setupFakeTimers() {
+  vi.useFakeTimers({ shouldAdvanceTime: true })
+  vi.setSystemTime(new Date('2026-04-19T15:00:00.000Z'))
+}
+
+// ─── Render helper ────────────────────────────────────────────────────────────
+
+function renderDialog(onOpenChange = vi.fn()) {
+  const qc = new QueryClient({
+    defaultOptions: { queries: { retry: false }, mutations: { retry: false } },
+  })
+  return {
+    qc,
+    result: render(
+      <QueryClientProvider client={qc}>
+        <AddProductPriceDialog
+          open={true}
+          onOpenChange={onOpenChange}
+          productId={1}
+        />
+      </QueryClientProvider>,
+    ),
+  }
+}
+
+// ─── Tests ────────────────────────────────────────────────────────────────────
+
+describe('AddProductPriceDialog — renders', () => {
+  it('renders dialog with price and date fields', () => {
+    renderDialog()
+    expect(screen.getByRole('dialog')).toBeInTheDocument()
+    // Use role spinbutton (number input) for price field
+    expect(screen.getByRole('spinbutton', { name: /precio$/i })).toBeInTheDocument()
+    expect(screen.getByLabelText(/vigente desde/i)).toBeInTheDocument()
+  })
+})
+
+describe('AddProductPriceDialog — client-side validation', () => {
+  beforeEach(() => {
+    setupFakeTimers()
+  })
+
+  it('shows error when priceValidFrom is yesterday (2026-04-18 < 2026-04-19)', async () => {
+    renderDialog()
+
+    const priceInput = screen.getByRole('spinbutton', { name: /precio$/i })
+    await userEvent.clear(priceInput)
+    await userEvent.type(priceInput, '100')
+
+    // "Yesterday" in ART = 2026-04-18
+    const dateInput = screen.getByLabelText(/vigente desde/i)
+    await userEvent.clear(dateInput)
+    await userEvent.type(dateInput, '2026-04-18')
+
+    const submitBtn = screen.getByRole('button', { name: /^guardar$/i })
+    await userEvent.click(submitBtn)
+
+    await waitFor(
+      () => expect(screen.getByText(/no puede ser anterior a hoy/i)).toBeInTheDocument(),
+      { timeout: 3000 },
+    )
+  })
+
+  it('accepts priceValidFrom = today (2026-04-19) as valid — no date error shown', async () => {
+    server.use(
+      http.post(`${API_URL}/api/v1/admin/products/1/prices`, () =>
+        HttpResponse.json(
+          {
+            created: { id: 1, productId: 1, price: 100, priceValidFrom: '2026-04-19', priceValidTo: null, isActive: true },
+            closed: null,
+          } satisfies AddProductPriceResponse,
+          { status: 201 },
+        ),
+      ),
+    )
+
+    const onOpenChange = vi.fn()
+    renderDialog(onOpenChange)
+
+    const priceInput = screen.getByRole('spinbutton', { name: /precio$/i })
+    await userEvent.clear(priceInput)
+    await userEvent.type(priceInput, '100')
+
+    const dateInput = screen.getByLabelText(/vigente desde/i)
+    await userEvent.clear(dateInput)
+    await userEvent.type(dateInput, '2026-04-19')
+
+    const submitBtn = screen.getByRole('button', { name: /^guardar$/i })
+    await userEvent.click(submitBtn)
+
+    // Should NOT show the date validation error
+    await waitFor(
+      () => expect(screen.queryByText(/no puede ser anterior a hoy/i)).not.toBeInTheDocument(),
+      { timeout: 3000 },
+    )
+  })
+
+  it('shows error when price is 0', async () => {
+    renderDialog()
+
+    const priceInput = screen.getByRole('spinbutton', { name: /precio$/i })
+    await userEvent.clear(priceInput)
+    await userEvent.type(priceInput, '0')
+
+    const dateInput = screen.getByLabelText(/vigente desde/i)
+    await userEvent.clear(dateInput)
+    await userEvent.type(dateInput, '2026-04-25')
+
+    const submitBtn = screen.getByRole('button', { name: /^guardar$/i })
+    await userEvent.click(submitBtn)
+
+    await waitFor(
+      () => expect(screen.getByText(/debe ser mayor/i)).toBeInTheDocument(),
+      { timeout: 3000 },
+    )
+  })
+
+  it('shows error when price is negative', async () => {
+    renderDialog()
+
+    const priceInput = screen.getByRole('spinbutton', { name: /precio$/i })
+    await userEvent.clear(priceInput)
+    await userEvent.type(priceInput, '-50')
+
+    const dateInput = screen.getByLabelText(/vigente desde/i)
+    await userEvent.clear(dateInput)
+    await userEvent.type(dateInput, '2026-04-25')
+
+    const submitBtn = screen.getByRole('button', { name: /^guardar$/i })
+    await userEvent.click(submitBtn)
+
+    await waitFor(
+      () => expect(screen.getByText(/debe ser mayor/i)).toBeInTheDocument(),
+      { timeout: 3000 },
+    )
+  })
+})
+
+describe('AddProductPriceDialog — happy path submit', () => {
+  beforeEach(() => {
+    setupFakeTimers()
+  })
+
+  it('calls mutation with correct payload and closes on success', async () => {
+    const mockResponse: AddProductPriceResponse = {
+      created: {
+        id: 2,
+        productId: 1,
+        price: 500.25,
+        priceValidFrom: '2026-04-25',
+        priceValidTo: null,
+        isActive: true,
+      },
+      closed: null,
+    }
+
+    let capturedBody: unknown = null
+    server.use(
+      http.post(`${API_URL}/api/v1/admin/products/1/prices`, async ({ request }) => {
+        capturedBody = await request.json()
+        return HttpResponse.json(mockResponse, { status: 201 })
+      }),
+    )
+
+    const onOpenChange = vi.fn()
+    renderDialog(onOpenChange)
+
+    const priceInput = screen.getByRole('spinbutton', { name: /precio$/i })
+    await userEvent.clear(priceInput)
+    await userEvent.type(priceInput, '500.25')
+
+    const dateInput = screen.getByLabelText(/vigente desde/i)
+    await userEvent.clear(dateInput)
+    await userEvent.type(dateInput, '2026-04-25')
+
+    await userEvent.click(screen.getByRole('button', { name: /^guardar$/i }))
+
+    await waitFor(
+      () => expect(capturedBody).toEqual({ price: 500.25, priceValidFrom: '2026-04-25' }),
+      { timeout: 3000 },
+    )
+    await waitFor(() => expect(onOpenChange).toHaveBeenCalledWith(false), { timeout: 3000 })
+  })
+})
+
+describe('AddProductPriceDialog — server error 409', () => {
+  beforeEach(() => {
+    setupFakeTimers()
+  })
+
+  it('shows inline message when server returns 409 (ForwardOnly)', async () => {
+    server.use(
+      http.post(`${API_URL}/api/v1/admin/products/1/prices`, () =>
+        HttpResponse.json(
+          {
+            error: 'product_price_forward_only',
+            message: 'La fecha debe ser posterior al precio vigente',
+          },
+          { status: 409 },
+        ),
+      ),
+    )
+    renderDialog()
+
+    const priceInput = screen.getByRole('spinbutton', { name: /precio$/i })
+    await userEvent.clear(priceInput)
+    await userEvent.type(priceInput, '100')
+
+    const dateInput = screen.getByLabelText(/vigente desde/i)
+    await userEvent.clear(dateInput)
+    await userEvent.type(dateInput, '2026-04-25')
+
+    await userEvent.click(screen.getByRole('button', { name: /^guardar$/i }))
+
+    await waitFor(
+      () => expect(screen.getByText(/fecha debe ser posterior/i)).toBeInTheDocument(),
+      { timeout: 3000 },
+    )
+  })
+})

src/web/src/tests/features/products/ProductPriceHistory.test.tsx

@@ -0,0 +1,199 @@
+import { describe, it, expect, beforeAll, afterAll, afterEach, vi } from 'vitest'
+import { render, screen, waitFor } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import { http, HttpResponse } from 'msw'
+import { setupServer } from 'msw/node'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import React from 'react'
+import { ProductPriceHistory } from '../../../features/products/components/ProductPriceHistory'
+import { useAuthStore } from '../../../stores/authStore'
+import type { ProductPrice } from '../../../features/products/types'
+
+const API_URL = 'http://localhost:5000'
+
+vi.mock('sonner', () => ({
+  toast: { success: vi.fn(), error: vi.fn() },
+}))
+
+// ─── Test data ────────────────────────────────────────────────────────────────
+
+const mockActivePrice: ProductPrice = {
+  id: 2,
+  productId: 1,
+  price: 1500.50,
+  priceValidFrom: '2026-04-01',
+  priceValidTo: null,
+  isActive: true,
+}
+
+const mockClosedPrice: ProductPrice = {
+  id: 1,
+  productId: 1,
+  price: 1000.00,
+  priceValidFrom: '2026-01-01',
+  priceValidTo: '2026-03-31',
+  isActive: false,
+}
+
+const adminUser = {
+  id: 1,
+  username: 'admin',
+  nombre: 'Admin',
+  rol: 'admin',
+  permisos: ['catalogo:productos:gestionar'],
+  mustChangePassword: false,
+}
+
+const regularUser = {
+  id: 2,
+  username: 'viewer',
+  nombre: 'Viewer',
+  rol: 'viewer',
+  permisos: [],
+  mustChangePassword: false,
+}
+
+// ─── Server ───────────────────────────────────────────────────────────────────
+
+const server = setupServer()
+
+beforeAll(() => server.listen({ onUnhandledRequest: 'error' }))
+afterEach(() => {
+  server.resetHandlers()
+  useAuthStore.getState().clearAuth()
+  vi.clearAllMocks()
+})
+afterAll(() => server.close())
+
+// ─── Render helper ────────────────────────────────────────────────────────────
+
+function renderHistory(productId = 1, user = adminUser) {
+  useAuthStore.setState({ user })
+  const qc = new QueryClient({
+    defaultOptions: { queries: { retry: false }, mutations: { retry: false } },
+  })
+  return render(
+    <QueryClientProvider client={qc}>
+      <ProductPriceHistory productId={productId} />
+    </QueryClientProvider>,
+  )
+}
+
+// ─── Tests ────────────────────────────────────────────────────────────────────
+
+describe('ProductPriceHistory — loading state', () => {
+  it('renders skeleton while loading', () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, async () => {
+        await new Promise(() => {})
+        return HttpResponse.json([])
+      }),
+    )
+    renderHistory()
+    // Should show loading indicator
+    const skeletons = document.querySelectorAll('[class*="skeleton"], .animate-pulse')
+    expect(skeletons.length).toBeGreaterThan(0)
+  })
+})
+
+describe('ProductPriceHistory — error state', () => {
+  it('renders error message on fetch failure', async () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, () =>
+        HttpResponse.json({ error: 'server_error' }, { status: 500 }),
+      ),
+    )
+    renderHistory()
+    await waitFor(() =>
+      expect(screen.getByText(/error al cargar precios/i)).toBeInTheDocument(),
+    )
+  })
+})
+
+describe('ProductPriceHistory — empty state', () => {
+  it('shows CTA when no prices exist', async () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, () => HttpResponse.json([])),
+    )
+    renderHistory()
+    await waitFor(() =>
+      expect(screen.getByText(/sin historial de precios/i)).toBeInTheDocument(),
+    )
+    // Should show at least one button to add first price (for users with permission)
+    // Both header button and empty-state CTA render in empty state
+    const addButtons = screen.getAllByRole('button', { name: /programar nuevo precio/i })
+    expect(addButtons.length).toBeGreaterThan(0)
+  })
+})
+
+describe('ProductPriceHistory — data rendering', () => {
+  it('renders price list with formatted dates and prices', async () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, () =>
+        HttpResponse.json([mockActivePrice, mockClosedPrice]),
+      ),
+    )
+    renderHistory()
+    await waitFor(() =>
+      expect(screen.getByText('01/04/2026')).toBeInTheDocument(),
+    )
+    // Active price row visible
+    expect(screen.getByText('01/01/2026')).toBeInTheDocument()
+    // Closed price "hasta" date visible
+    expect(screen.getByText('31/03/2026')).toBeInTheDocument()
+  })
+
+  it('shows Badge "Vigente" for active price row (priceValidTo=null)', async () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, () =>
+        HttpResponse.json([mockActivePrice, mockClosedPrice]),
+      ),
+    )
+    renderHistory()
+    await waitFor(() => expect(screen.getByText('Vigente')).toBeInTheDocument())
+  })
+
+  it('shows formatted currency for prices', async () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, () =>
+        HttpResponse.json([mockActivePrice]),
+      ),
+    )
+    renderHistory()
+    // ARS currency format — 1500.50
+    await waitFor(() => {
+      const cells = screen.getAllByRole('cell')
+      const hasCurrency = cells.some((c) => c.textContent?.includes('1.500') || c.textContent?.includes('1500'))
+      expect(hasCurrency).toBe(true)
+    })
+  })
+})
+
+describe('ProductPriceHistory — dialog integration', () => {
+  it('opens AddProductPriceDialog when "Programar nuevo precio" is clicked', async () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, () =>
+        HttpResponse.json([mockActivePrice]),
+      ),
+    )
+    renderHistory()
+    await waitFor(() => expect(screen.getByText('Vigente')).toBeInTheDocument())
+    const btn = screen.getByRole('button', { name: /programar nuevo precio/i })
+    await userEvent.click(btn)
+    // Dialog should open — check for dialog heading
+    await waitFor(() =>
+      expect(screen.getByRole('dialog')).toBeInTheDocument(),
+    )
+  })
+
+  it('hides "Programar nuevo precio" button when user lacks permission', async () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, () =>
+        HttpResponse.json([mockActivePrice]),
+      ),
+    )
+    renderHistory(1, regularUser)
+    await waitFor(() => expect(screen.getByText('Vigente')).toBeInTheDocument())
+    expect(screen.queryByRole('button', { name: /programar nuevo precio/i })).not.toBeInTheDocument()
+  })
+})

src/web/src/tests/features/products/productPrices.hooks.test.ts

@@ -0,0 +1,104 @@
+import { describe, it, expect, beforeAll, afterAll, afterEach, vi } from 'vitest'
+import { renderHook, waitFor, act } from '@testing-library/react'
+import { http, HttpResponse } from 'msw'
+import { setupServer } from 'msw/node'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import React from 'react'
+import { useProductPrices } from '../../../features/products/hooks/useProductPrices'
+import { useAddProductPrice } from '../../../features/products/hooks/useAddProductPrice'
+import type { ProductPrice, AddProductPriceResponse } from '../../../features/products/types'
+
+const API_URL = 'http://localhost:5000'
+
+vi.mock('sonner', () => ({
+  toast: { success: vi.fn(), error: vi.fn() },
+}))
+
+const mockPrice: ProductPrice = {
+  id: 1,
+  productId: 1,
+  price: 500,
+  priceValidFrom: '2026-04-01',
+  priceValidTo: null,
+  isActive: true,
+}
+
+const mockResponse: AddProductPriceResponse = {
+  created: { id: 2, productId: 1, price: 700, priceValidFrom: '2026-05-01', priceValidTo: null, isActive: true },
+  closed: { id: 1, productId: 1, price: 500, priceValidFrom: '2026-04-01', priceValidTo: '2026-04-30', isActive: false },
+}
+
+const server = setupServer()
+
+beforeAll(() => server.listen({ onUnhandledRequest: 'error' }))
+afterEach(() => {
+  server.resetHandlers()
+  vi.clearAllMocks()
+})
+afterAll(() => server.close())
+
+function makeWrapper() {
+  const qc = new QueryClient({
+    defaultOptions: { queries: { retry: false }, mutations: { retry: false } },
+  })
+  return { qc, wrapper: ({ children }: { children: React.ReactNode }) =>
+    React.createElement(QueryClientProvider, { client: qc }, children) }
+}
+
+describe('useProductPrices', () => {
+  it('fetches prices for productId and returns data', async () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, () => HttpResponse.json([mockPrice])),
+    )
+    const { qc, wrapper } = makeWrapper()
+    const { result } = renderHook(() => useProductPrices(1), { wrapper })
+    await waitFor(() => expect(result.current.isSuccess).toBe(true))
+    expect(result.current.data).toEqual([mockPrice])
+    // Verify caching: queryKey should be ['products', 1, 'prices']
+    expect(qc.getQueryState(['products', 1, 'prices'])).toBeDefined()
+  })
+
+  it('is disabled when productId is 0', async () => {
+    // No server handler — if the query fired it would fail with unhandled request
+    const { wrapper } = makeWrapper()
+    const { result } = renderHook(() => useProductPrices(0), { wrapper })
+    // Should never enter loading/success
+    expect(result.current.isFetching).toBe(false)
+    expect(result.current.data).toBeUndefined()
+  })
+})
+
+describe('useAddProductPrice', () => {
+  it('calls POST and invalidates product prices queries on success', async () => {
+    server.use(
+      http.get(`${API_URL}/api/v1/products/1/prices`, () => HttpResponse.json([mockPrice])),
+      http.post(`${API_URL}/api/v1/admin/products/1/prices`, () =>
+        HttpResponse.json(mockResponse, { status: 201 }),
+      ),
+    )
+    const { qc, wrapper } = makeWrapper()
+    const invalidateSpy = vi.spyOn(qc, 'invalidateQueries')
+
+    const { result } = renderHook(() => useAddProductPrice(1), { wrapper })
+
+    await act(async () => {
+      result.current.mutate({ price: 700, priceValidFrom: '2026-05-01' })
+    })
+    await waitFor(() => expect(result.current.isSuccess).toBe(true))
+    expect(invalidateSpy).toHaveBeenCalledWith({ queryKey: ['products', 1, 'prices'] })
+  })
+
+  it('returns error state on 409', async () => {
+    server.use(
+      http.post(`${API_URL}/api/v1/admin/products/1/prices`, () =>
+        HttpResponse.json({ error: 'product_price_forward_only' }, { status: 409 }),
+      ),
+    )
+    const { wrapper } = makeWrapper()
+    const { result } = renderHook(() => useAddProductPrice(1), { wrapper })
+    await act(async () => {
+      result.current.mutate({ price: 100, priceValidFrom: '2026-04-19' })
+    })
+    await waitFor(() => expect(result.current.isError).toBe(true))
+  })
+})

tests/SIGCM2.Api.Tests/Products/ProductPricesAuditFailureTests.cs

@@ -0,0 +1,157 @@
+using System.Net;
+using System.Net.Http.Headers;
+using System.Net.Http.Json;
+using System.Text.Json;
+using Dapper;
+using FluentAssertions;
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using NSubstitute;
+using NSubstitute.ExceptionExtensions;
+using SIGCM2.Application.Abstractions.Security;
+using SIGCM2.Application.Audit;
+using SIGCM2.Domain.Entities;
+using SIGCM2.TestSupport;
+using Xunit;
+
+namespace SIGCM2.Api.Tests.Products;
+
+/// <summary>
+/// PRD-003 — Batch 7 / T7.4: Audit failure e2e test.
+///
+/// Verifies that when IAuditLogger.LogAsync throws, the TransactionScope rolls back:
+///   - dbo.ProductPrices row is NOT inserted (fail-closed).
+///   - dbo.AuditEvent row is NOT created.
+///   - HTTP response is 500 (unhandled exception propagates through ExceptionFilter).
+///
+/// Uses CreateClientWithOverrides (pattern from issue #36) to inject a throwing IAuditLogger
+/// mock without touching the shared factory.
+///
+/// DB: SIGCM2_Test_Api (ApiIntegration collection).
+/// </summary>
+[Collection("ApiIntegration")]
+public sealed class ProductPricesAuditFailureTests : IAsyncLifetime
+{
+    private const string ConnectionString = TestConnectionStrings.ApiTestDb;
+
+    private readonly TestWebAppFactory _factory;
+    private int _medioId;
+    private int _productTypeId;
+
+    public ProductPricesAuditFailureTests(TestWebAppFactory factory)
+    {
+        _factory = factory;
+    }
+
+    public async Task InitializeAsync()
+    {
+        await using var conn = new SqlConnection(ConnectionString);
+        await conn.OpenAsync();
+
+        _medioId = await conn.QuerySingleAsync<int>(
+            "SELECT TOP 1 Id FROM dbo.Medio WHERE Activo = 1 ORDER BY Id");
+
+        var ptId = await conn.QuerySingleOrDefaultAsync<int?>(
+            "SELECT TOP 1 Id FROM dbo.ProductType WHERE IsActive = 1 ORDER BY Id");
+        if (ptId is null)
+        {
+            ptId = await conn.QuerySingleAsync<int>("""
+                INSERT INTO dbo.ProductType (Nombre, HasDuration, RequiresText, RequiresCategory, IsBundle, AllowImages, IsActive, FechaCreacion)
+                VALUES ('PT_AuditFail_Test', 0, 0, 0, 0, 0, 1, SYSUTCDATETIME());
+                SELECT CAST(SCOPE_IDENTITY() AS INT);
+                """);
+        }
+        _productTypeId = ptId.Value;
+    }
+
+    public Task DisposeAsync() => Task.CompletedTask;
+
+    // ── T7.4 — Audit failure rolls back the ProductPrice insert ──────────────
+
+    [Fact]
+    public async Task PostPrice_WhenAuditLoggerThrows_Returns500AndRollsBackInsert()
+    {
+        // Arrange: seed a unique product
+        var productId = await SeedProductAsync();
+
+        // Count rows before the failing POST
+        await using var conn = new SqlConnection(ConnectionString);
+        await conn.OpenAsync();
+
+        var priceCountBefore = await conn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.ProductPrices WHERE ProductId = @ProductId",
+            new { ProductId = productId });
+
+        var auditCountBefore = await conn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.AuditEvent WHERE Action = 'product_price.created' AND TargetType = 'ProductPrice'");
+
+        // Build a mock IAuditLogger that throws on LogAsync
+        var throwingAuditLogger = Substitute.For<IAuditLogger>();
+        throwingAuditLogger
+            .LogAsync(
+                Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(),
+                Arg.Any<object?>(), Arg.Any<CancellationToken>())
+            .ThrowsAsync(new InvalidOperationException("audit down — simulated failure"));
+
+        // Use CreateClientWithOverrides to inject the mock without touching the shared factory
+        using var client = _factory.CreateClientWithOverrides(services =>
+        {
+            services.RemoveAll<IAuditLogger>();
+            services.AddScoped<IAuditLogger>(_ => throwingAuditLogger);
+        });
+
+        // Generate admin token (use factory services, not child)
+        var jwt = _factory.Services.GetRequiredService<IJwtService>();
+        var token = jwt.GenerateAccessToken(new Usuario(
+            id: 1, username: "admin", passwordHash: "x",
+            nombre: "Admin", apellido: "Sys", email: null,
+            rol: "admin", permisosJson: """{"grant":[],"deny":[]}""", activo: true));
+
+        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");
+
+        var req = new HttpRequestMessage(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices");
+        req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
+        req.Content = JsonContent.Create(new { price = 999m, priceValidFrom = pvf });
+
+        // Act
+        var resp = await client.SendAsync(req);
+
+        // Assert HTTP: audit failure → unhandled exception → 500
+        resp.StatusCode.Should().Be(HttpStatusCode.InternalServerError,
+            because: "IAuditLogger throwing must propagate as 500 (fail-closed)");
+
+        // Assert DB: NO new ProductPrices row was persisted (TransactionScope rolled back)
+        await using var verifyConn = new SqlConnection(ConnectionString);
+        await verifyConn.OpenAsync();
+
+        var priceCountAfter = await verifyConn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.ProductPrices WHERE ProductId = @ProductId",
+            new { ProductId = productId });
+
+        priceCountAfter.Should().Be(priceCountBefore,
+            because: "TransactionScope must roll back the ProductPrices INSERT when audit fails");
+
+        // Assert DB: NO new AuditEvent row for this product
+        var auditCountAfter = await verifyConn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.AuditEvent WHERE Action = 'product_price.created' AND TargetType = 'ProductPrice'");
+
+        auditCountAfter.Should().Be(auditCountBefore,
+            because: "no AuditEvent row must be created when the audit logger throws");
+    }
+
+    // ── Helper: seed an active product ───────────────────────────────────────
+
+    private async Task<int> SeedProductAsync()
+    {
+        await using var conn = new SqlConnection(ConnectionString);
+        await conn.OpenAsync();
+        var nombre = $"PP_AF_{Guid.NewGuid():N}"[..35];
+        return await conn.QuerySingleAsync<int>("""
+            INSERT INTO dbo.Product (Nombre, MedioId, ProductTypeId, BasePrice, PriceDurationDays, IsActive, FechaCreacion)
+            VALUES (@Nombre, @MedioId, @PtId, 100.00, NULL, 1, SYSUTCDATETIME());
+            SELECT CAST(SCOPE_IDENTITY() AS INT);
+            """,
+            new { Nombre = nombre, MedioId = _medioId, PtId = _productTypeId });
+    }
+}

tests/SIGCM2.Api.Tests/Products/ProductPricesControllerTests.cs

@@ -0,0 +1,450 @@
+using System.Net;
+using System.Net.Http.Headers;
+using System.Net.Http.Json;
+using System.Text.Json;
+using Dapper;
+using FluentAssertions;
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.DependencyInjection;
+using SIGCM2.Application.Abstractions.Security;
+using SIGCM2.Domain.Entities;
+using SIGCM2.TestSupport;
+using Xunit;
+
+namespace SIGCM2.Api.Tests.Products;
+
+/// <summary>
+/// PRD-003 — Integration tests for:
+///   GET  /api/v1/products/{id}/prices       (requires authentication)
+///   POST /api/v1/admin/products/{id}/prices  (requires catalogo:productos:gestionar)
+/// DB: SIGCM2_Test_Api (ApiIntegration collection — shared TestWebAppFactory).
+///
+/// Each test creates its own product (via SQL) to avoid inter-test dependencies.
+/// </summary>
+[Collection("ApiIntegration")]
+public sealed class ProductPricesControllerTests : IAsyncLifetime
+{
+    private const string ConnectionString = TestConnectionStrings.ApiTestDb;
+
+    private readonly TestWebAppFactory _factory;
+    private readonly HttpClient _client;
+
+    // Seeded once per class — valid MedioId and ProductTypeId from canonical data
+    private int _medioId;
+    private int _productTypeId;
+
+    public ProductPricesControllerTests(TestWebAppFactory factory)
+    {
+        _factory = factory;
+        _client = factory.CreateClient();
+    }
+
+    // ── Lifecycle ─────────────────────────────────────────────────────────────
+
+    public async Task InitializeAsync()
+    {
+        await using var conn = new SqlConnection(ConnectionString);
+        await conn.OpenAsync();
+
+        // Resolve a valid MedioId (dbo.Medio uses 'Activo' column)
+        _medioId = await conn.QuerySingleAsync<int>(
+            "SELECT TOP 1 Id FROM dbo.Medio WHERE Activo = 1 ORDER BY Id");
+
+        // Resolve or seed a valid ProductTypeId (dbo.ProductType uses 'IsActive' column)
+        var ptId = await conn.QuerySingleOrDefaultAsync<int?>(
+            "SELECT TOP 1 Id FROM dbo.ProductType WHERE IsActive = 1 ORDER BY Id");
+        if (ptId is null)
+        {
+            ptId = await conn.QuerySingleAsync<int>("""
+                INSERT INTO dbo.ProductType (Nombre, HasDuration, RequiresText, RequiresCategory, IsBundle, AllowImages, IsActive, FechaCreacion)
+                VALUES ('PT_Prices_Test', 0, 0, 0, 0, 0, 1, SYSUTCDATETIME());
+                SELECT CAST(SCOPE_IDENTITY() AS INT);
+                """);
+        }
+        _productTypeId = ptId.Value;
+    }
+
+    public Task DisposeAsync() => Task.CompletedTask;
+
+    // ── Auth helpers ──────────────────────────────────────────────────────────
+
+    /// <summary>Generates a bearer token for admin (has catalogo:productos:gestionar via 'admin' role).</summary>
+    private string GetAdminToken()
+    {
+        var jwt = _factory.Services.GetRequiredService<IJwtService>();
+        return jwt.GenerateAccessToken(new Usuario(
+            id: 1, username: "admin", passwordHash: "x",
+            nombre: "Admin", apellido: "Sys", email: null,
+            rol: "admin", permisosJson: """{"grant":[],"deny":[]}""", activo: true));
+    }
+
+    /// <summary>Generates a bearer token for cajero (does NOT have catalogo:productos:gestionar).</summary>
+    private string GetCajeroToken()
+    {
+        var jwt = _factory.Services.GetRequiredService<IJwtService>();
+        return jwt.GenerateAccessToken(new Usuario(
+            id: 9999, username: "cajero_test", passwordHash: "x",
+            nombre: "Cajero", apellido: "Test", email: null,
+            rol: "cajero", permisosJson: """{"grant":[],"deny":[]}""", activo: true));
+    }
+
+    private HttpRequestMessage BuildRequest(
+        HttpMethod method, string url, object? body = null, string? token = null)
+    {
+        var req = new HttpRequestMessage(method, url);
+        if (token is not null)
+            req.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
+        if (body is not null)
+            req.Content = JsonContent.Create(body);
+        return req;
+    }
+
+    // ── DB seed helpers ───────────────────────────────────────────────────────
+
+    /// <summary>Seeds a unique product and returns its Id.</summary>
+    private async Task<int> SeedProductAsync(bool activo = true)
+    {
+        await using var conn = new SqlConnection(ConnectionString);
+        await conn.OpenAsync();
+        var nombre = $"PP_{Guid.NewGuid():N}"[..35];
+        // dbo.Product uses 'IsActive' column (PRD-002 convention)
+        return await conn.QuerySingleAsync<int>("""
+            INSERT INTO dbo.Product (Nombre, MedioId, ProductTypeId, BasePrice, PriceDurationDays, IsActive, FechaCreacion)
+            VALUES (@Nombre, @MedioId, @PtId, 100.00, NULL, @IsActive, SYSUTCDATETIME());
+            SELECT CAST(SCOPE_IDENTITY() AS INT);
+            """,
+            new { Nombre = nombre, MedioId = _medioId, PtId = _productTypeId, IsActive = activo ? 1 : 0 });
+    }
+
+    /// <summary>
+    /// Inserts a ProductPrice row directly (bypasses SP forward-only guard) to set up test scenarios.
+    /// </summary>
+    private async Task<long> SeedPriceDirectAsync(
+        int productId, decimal price, DateOnly pvf, DateOnly? pvt)
+    {
+        await using var conn = new SqlConnection(ConnectionString);
+        await conn.OpenAsync();
+        return await conn.QuerySingleAsync<long>("""
+            INSERT INTO dbo.ProductPrices (ProductId, Price, PriceValidFrom, PriceValidTo, FechaCreacion)
+            VALUES (@ProductId, @Price, @PriceValidFrom, @PriceValidTo, SYSUTCDATETIME());
+            SELECT CAST(SCOPE_IDENTITY() AS BIGINT);
+            """,
+            new
+            {
+                ProductId = productId,
+                Price = price,
+                PriceValidFrom = pvf.ToDateTime(TimeOnly.MinValue),
+                PriceValidTo = pvt.HasValue ? (DateTime?)pvt.Value.ToDateTime(TimeOnly.MinValue) : null
+            });
+    }
+
+    // ── GET /api/v1/products/{id}/prices ─────────────────────────────────────
+
+    [Fact]
+    public async Task GetPrices_WithoutAuth_Returns401()
+    {
+        using var req = BuildRequest(HttpMethod.Get, "/api/v1/products/1/prices");
+        var resp = await _client.SendAsync(req);
+        resp.StatusCode.Should().Be(HttpStatusCode.Unauthorized);
+    }
+
+    [Fact]
+    public async Task GetPrices_EmptyHistory_Returns200WithEmptyArray()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+
+        using var req = BuildRequest(HttpMethod.Get, $"/api/v1/products/{productId}/prices", token: token);
+        var resp = await _client.SendAsync(req);
+
+        resp.StatusCode.Should().Be(HttpStatusCode.OK);
+        var json = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        json.ValueKind.Should().Be(JsonValueKind.Array);
+        json.GetArrayLength().Should().Be(0);
+    }
+
+    [Fact]
+    public async Task GetPrices_WithHistory_Returns200OrderedDescending()
+    {
+        var productId = await SeedProductAsync();
+
+        // Seed 3 prices: 2 closed + 1 active (in ascending order to verify API returns DESC)
+        await SeedPriceDirectAsync(productId, 50m,  new DateOnly(2026, 1, 1), new DateOnly(2026, 1, 31));
+        await SeedPriceDirectAsync(productId, 75m,  new DateOnly(2026, 2, 1), new DateOnly(2026, 2, 28));
+        await SeedPriceDirectAsync(productId, 100m, new DateOnly(2026, 3, 1), null);
+
+        var token = GetAdminToken();
+        using var req = BuildRequest(HttpMethod.Get, $"/api/v1/products/{productId}/prices", token: token);
+        var resp = await _client.SendAsync(req);
+
+        resp.StatusCode.Should().Be(HttpStatusCode.OK);
+        var items = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        items.GetArrayLength().Should().Be(3);
+
+        // First item = most recent (active, March)
+        var first = items[0];
+        first.GetProperty("priceValidFrom").GetString().Should().Be("2026-03-01");
+        first.GetProperty("isActive").GetBoolean().Should().BeTrue();
+        first.GetProperty("priceValidTo").ValueKind.Should().Be(JsonValueKind.Null);
+
+        // Last item = oldest (January)
+        var last = items[2];
+        last.GetProperty("priceValidFrom").GetString().Should().Be("2026-01-01");
+        last.GetProperty("isActive").GetBoolean().Should().BeFalse();
+        last.GetProperty("priceValidTo").GetString().Should().Be("2026-01-31");
+    }
+
+    [Fact]
+    public async Task GetPrices_ProductNotFound_Returns404()
+    {
+        var token = GetAdminToken();
+        using var req = BuildRequest(HttpMethod.Get, "/api/v1/products/999999999/prices", token: token);
+        var resp = await _client.SendAsync(req);
+
+        resp.StatusCode.Should().Be(HttpStatusCode.NotFound);
+        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        body.GetProperty("error").GetString().Should().Be("product_not_found");
+    }
+
+    // ── POST /api/v1/admin/products/{id}/prices ───────────────────────────────
+
+    [Fact]
+    public async Task PostPrice_WithoutAuth_Returns401()
+    {
+        using var req = BuildRequest(HttpMethod.Post, "/api/v1/admin/products/1/prices",
+            body: new { price = 200m, priceValidFrom = "2026-05-01" });
+        var resp = await _client.SendAsync(req);
+        resp.StatusCode.Should().Be(HttpStatusCode.Unauthorized);
+    }
+
+    [Fact]
+    public async Task PostPrice_WithoutPermission_Returns403()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetCajeroToken();
+        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");
+
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = 200m, priceValidFrom = pvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+        resp.StatusCode.Should().Be(HttpStatusCode.Forbidden);
+    }
+
+    [Fact]
+    public async Task PostPrice_FirstPrice_Returns201WithClosedNull()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+        // Use tomorrow to ensure >= hoy_AR passes FluentValidation
+        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");
+
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = 250m, priceValidFrom = pvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+
+        resp.StatusCode.Should().Be(HttpStatusCode.Created);
+
+        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        body.TryGetProperty("created", out var created).Should().BeTrue();
+        body.TryGetProperty("closed", out var closed).Should().BeTrue();
+
+        created.GetProperty("price").GetDecimal().Should().Be(250m);
+        created.GetProperty("priceValidFrom").GetString().Should().Be(pvf);
+        created.GetProperty("isActive").GetBoolean().Should().BeTrue();
+        closed.ValueKind.Should().Be(JsonValueKind.Null);
+
+        // Location header must be present
+        resp.Headers.Location.Should().NotBeNull();
+    }
+
+    [Fact]
+    public async Task PostPrice_SecondPrice_Returns201WithClosedNotNull()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+
+        // Seed an existing active price at a past date (direct insert bypasses SP)
+        await SeedPriceDirectAsync(productId, 100m, new DateOnly(2026, 4, 1), null);
+
+        // New price must be strictly greater than active PVF
+        var newPvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(2).ToString("yyyy-MM-dd");
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = 300m, priceValidFrom = newPvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+
+        resp.StatusCode.Should().Be(HttpStatusCode.Created);
+
+        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        var closed = body.GetProperty("closed");
+        closed.ValueKind.Should().NotBe(JsonValueKind.Null);
+        closed.GetProperty("price").GetDecimal().Should().Be(100m);
+
+        // PriceValidTo of closed = newPvf - 1 day
+        var expectedPvt = DateOnly.ParseExact(newPvf, "yyyy-MM-dd").AddDays(-1).ToString("yyyy-MM-dd");
+        closed.GetProperty("priceValidTo").GetString().Should().Be(expectedPvt);
+
+        var created = body.GetProperty("created");
+        created.GetProperty("price").GetDecimal().Should().Be(300m);
+        created.GetProperty("priceValidFrom").GetString().Should().Be(newPvf);
+        created.GetProperty("isActive").GetBoolean().Should().BeTrue();
+    }
+
+    [Fact]
+    public async Task PostPrice_PriceZero_Returns400()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");
+
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = 0m, priceValidFrom = pvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+        resp.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+    }
+
+    [Fact]
+    public async Task PostPrice_NegativePrice_Returns400()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");
+
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = -5m, priceValidFrom = pvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+        resp.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+    }
+
+    [Fact]
+    public async Task PostPrice_PastDate_Returns400()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+        // Clearly in the past
+        const string pastDate = "2020-01-01";
+
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = 100m, priceValidFrom = pastDate },
+            token: token);
+        var resp = await _client.SendAsync(req);
+        resp.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+    }
+
+    [Fact]
+    public async Task PostPrice_ProductNotFound_Returns404()
+    {
+        var token = GetAdminToken();
+        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");
+
+        using var req = BuildRequest(HttpMethod.Post, "/api/v1/admin/products/999999999/prices",
+            body: new { price = 100m, priceValidFrom = pvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+
+        resp.StatusCode.Should().Be(HttpStatusCode.NotFound);
+        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        body.GetProperty("error").GetString().Should().Be("product_not_found");
+    }
+
+    [Fact]
+    public async Task PostPrice_ForwardOnlyViolation_Returns409()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+
+        // Seed active price at a far-future date
+        await SeedPriceDirectAsync(productId, 200m, new DateOnly(2099, 12, 1), null);
+
+        // Try to add price with a date BEFORE the active one
+        const string retroPvf = "2099-11-01";
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = 150m, priceValidFrom = retroPvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+
+        resp.StatusCode.Should().Be(HttpStatusCode.Conflict);
+        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        body.GetProperty("error").GetString().Should().Be("product_price_forward_only");
+    }
+
+    [Fact]
+    public async Task PostPrice_SamePvfAsActive_Returns409()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+
+        // Seed active price at a far-future date
+        await SeedPriceDirectAsync(productId, 200m, new DateOnly(2099, 12, 1), null);
+
+        // Try to add price with the SAME date — also rejected (forward-only: must be strictly greater)
+        const string samePvf = "2099-12-01";
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = 250m, priceValidFrom = samePvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+
+        resp.StatusCode.Should().Be(HttpStatusCode.Conflict);
+        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        body.GetProperty("error").GetString().Should().Be("product_price_forward_only");
+    }
+
+    // ── Audit Event ───────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task PostPrice_Success_CreatesAuditEvent()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");
+
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = 500m, priceValidFrom = pvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+        resp.StatusCode.Should().Be(HttpStatusCode.Created);
+
+        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        var newId = body.GetProperty("created").GetProperty("id").GetInt64();
+
+        // Verify audit event row in SIGCM2_Test_Api
+        await using var conn = new SqlConnection(ConnectionString);
+        await conn.OpenAsync();
+        var auditCount = await conn.QuerySingleAsync<int>("""
+            SELECT COUNT(1) FROM dbo.AuditEvent
+            WHERE Action = 'product_price.created'
+              AND TargetType = 'ProductPrice'
+              AND TargetId = @TargetId
+            """, new { TargetId = newId.ToString() });
+
+        auditCount.Should().Be(1, because: "IAuditLogger must record product_price.created after a successful POST");
+    }
+
+    // ── DateOnly JSON format ──────────────────────────────────────────────────
+
+    [Fact]
+    public async Task PostPrice_DateOnly_SerializesAsYyyyMmDd()
+    {
+        var productId = await SeedProductAsync();
+        var token = GetAdminToken();
+        var pvf = DateOnly.FromDateTime(DateTime.UtcNow).AddDays(1).ToString("yyyy-MM-dd");
+
+        using var req = BuildRequest(HttpMethod.Post, $"/api/v1/admin/products/{productId}/prices",
+            body: new { price = 999m, priceValidFrom = pvf },
+            token: token);
+        var resp = await _client.SendAsync(req);
+        resp.StatusCode.Should().Be(HttpStatusCode.Created);
+
+        var body = await resp.Content.ReadFromJsonAsync<JsonElement>();
+        var returnedPvf = body.GetProperty("created").GetProperty("priceValidFrom").GetString();
+
+        // DateOnlyJsonConverter must produce "yyyy-MM-dd" — no time, no TZ suffix
+        returnedPvf.Should().MatchRegex(@"^\d{4}-\d{2}-\d{2}$",
+            because: "DateOnlyJsonConverter (UDT-011) must serialize DateOnly as yyyy-MM-dd");
+        returnedPvf.Should().Be(pvf);
+    }
+}

tests/SIGCM2.Application.Tests/Domain/ProductPriceExceptionTests.cs

@@ -0,0 +1,128 @@
+using FluentAssertions;
+using SIGCM2.Domain.Exceptions;
+
+namespace SIGCM2.Application.Tests.Domain;
+
+/// <summary>
+/// PRD-003 — Domain unit tests for ProductPrice-related exceptions.
+/// Verifies constructor props, message content, and DomainException inheritance.
+/// </summary>
+public class ProductPriceExceptionTests
+{
+    // ── ProductPriceForwardOnlyException ─────────────────────────────────────
+
+    [Fact]
+    public void ProductPriceForwardOnlyException_SetsProperties()
+    {
+        var newPvf    = new DateOnly(2026, 3, 1);
+        var activePvf = new DateOnly(2026, 4, 1);
+
+        var ex = new ProductPriceForwardOnlyException(productId: 42, newPvf, activePvf);
+
+        ex.ProductId.Should().Be(42);
+        ex.NewPriceValidFrom.Should().Be(newPvf);
+        ex.ActivePriceValidFrom.Should().Be(activePvf);
+    }
+
+    [Fact]
+    public void ProductPriceForwardOnlyException_MessageContainsKeyDates()
+    {
+        var newPvf    = new DateOnly(2026, 3, 1);
+        var activePvf = new DateOnly(2026, 4, 1);
+
+        var ex = new ProductPriceForwardOnlyException(productId: 5, newPvf, activePvf);
+
+        ex.Message.Should().Contain("2026-03-01");
+        ex.Message.Should().Contain("2026-04-01");
+    }
+
+    [Fact]
+    public void ProductPriceForwardOnlyException_InheritsFromDomainException()
+    {
+        var ex = new ProductPriceForwardOnlyException(
+            productId: 1,
+            newPriceValidFrom: new DateOnly(2026, 1, 1),
+            activePriceValidFrom: new DateOnly(2026, 2, 1));
+
+        ex.Should().BeAssignableTo<DomainException>();
+    }
+
+    // ── ProductPriceInvalidException ─────────────────────────────────────────
+
+    [Fact]
+    public void ProductPriceInvalidException_SetsProperties()
+    {
+        var ex = new ProductPriceInvalidException(field: "Price", reason: "must be > 0");
+
+        ex.Field.Should().Be("Price");
+        ex.Reason.Should().Be("must be > 0");
+    }
+
+    [Fact]
+    public void ProductPriceInvalidException_MessageContainsFieldAndReason()
+    {
+        var ex = new ProductPriceInvalidException(field: "Price", reason: "must be > 0");
+
+        ex.Message.Should().Contain("Price");
+        ex.Message.Should().Contain("must be > 0");
+    }
+
+    [Fact]
+    public void ProductPriceInvalidException_InheritsFromDomainException()
+    {
+        var ex = new ProductPriceInvalidException("Price", "invalid");
+
+        ex.Should().BeAssignableTo<DomainException>();
+    }
+
+    // ── ProductSinPrecioActivoException ──────────────────────────────────────
+
+    [Fact]
+    public void ProductSinPrecioActivoException_SetsProperties()
+    {
+        var date = new DateOnly(2026, 4, 19);
+
+        var ex = new ProductSinPrecioActivoException(productId: 99, date);
+
+        ex.ProductId.Should().Be(99);
+        ex.Date.Should().Be(date);
+    }
+
+    [Fact]
+    public void ProductSinPrecioActivoException_MessageContainsProductIdAndDate()
+    {
+        var date = new DateOnly(2026, 4, 19);
+
+        var ex = new ProductSinPrecioActivoException(productId: 99, date);
+
+        ex.Message.Should().Contain("99");
+        ex.Message.Should().Contain("2026-04-19");
+    }
+
+    [Fact]
+    public void ProductSinPrecioActivoException_InheritsFromDomainException()
+    {
+        var ex = new ProductSinPrecioActivoException(1, new DateOnly(2026, 4, 1));
+
+        ex.Should().BeAssignableTo<DomainException>();
+    }
+
+    // ── ProductNotFoundException — already exists, verify it works ────────────
+
+    [Fact]
+    public void ProductNotFoundException_SetsProductIdAndMessage()
+    {
+        var ex = new ProductNotFoundException(77);
+
+        ex.ProductId.Should().Be(77);
+        ex.Message.Should().Contain("77");
+    }
+
+    [Fact]
+    public void ProductNotFoundException_InheritsFromDomainException()
+    {
+        var ex = new ProductNotFoundException(1);
+
+        ex.Should().BeAssignableTo<DomainException>();
+    }
+}

tests/SIGCM2.Application.Tests/Domain/ProductPriceTests.cs

@@ -0,0 +1,158 @@
+using FluentAssertions;
+using SIGCM2.Domain.Entities;
+
+namespace SIGCM2.Application.Tests.Domain;
+
+/// <summary>
+/// PRD-003 — Domain unit tests for ProductPrice record.
+/// Covers: §REQ-4.1 (IsActive), §REQ-4.2 (CoversDate inclusive bounds),
+///          §REQ-4.4 (active row covers any date on or after PriceValidFrom).
+/// </summary>
+public class ProductPriceTests
+{
+    private static ProductPrice MakePrice(
+        long id = 1,
+        int productId = 10,
+        decimal price = 1500.00m,
+        DateOnly? from = null,
+        DateOnly? to = null,
+        DateTime? fechaCreacion = null)
+        => new(
+            Id: id,
+            ProductId: productId,
+            Price: price,
+            PriceValidFrom: from ?? new DateOnly(2026, 4, 1),
+            PriceValidTo: to,
+            FechaCreacion: fechaCreacion ?? new DateTime(2026, 4, 1, 0, 0, 0, DateTimeKind.Utc));
+
+    // ── §REQ-4.1: IsActive ────────────────────────────────────────────────────
+
+    [Fact]
+    public void IsActive_TrueWhenPriceValidToIsNull()
+    {
+        var price = MakePrice(to: null);
+
+        price.IsActive.Should().BeTrue();
+    }
+
+    [Fact]
+    public void IsActive_FalseWhenPriceValidToHasValue()
+    {
+        var price = MakePrice(to: new DateOnly(2026, 4, 30));
+
+        price.IsActive.Should().BeFalse();
+    }
+
+    // ── §REQ-4.2: CoversDate — inclusive lower bound ──────────────────────────
+
+    [Fact]
+    public void CoversDate_InclusiveLowerBound_ReturnsTrue()
+    {
+        // Row: 2026-04-01 → 2026-04-30. Query date = PriceValidFrom.
+        var price = MakePrice(from: new DateOnly(2026, 4, 1), to: new DateOnly(2026, 4, 30));
+
+        price.CoversDate(new DateOnly(2026, 4, 1)).Should().BeTrue();
+    }
+
+    // ── §REQ-4.2: CoversDate — inclusive upper bound ──────────────────────────
+
+    [Fact]
+    public void CoversDate_InclusiveUpperBound_ReturnsTrue()
+    {
+        // Row: 2026-04-01 → 2026-04-30. Query date = PriceValidTo.
+        var price = MakePrice(from: new DateOnly(2026, 4, 1), to: new DateOnly(2026, 4, 30));
+
+        price.CoversDate(new DateOnly(2026, 4, 30)).Should().BeTrue();
+    }
+
+    // ── §REQ-4.2: CoversDate — exclusive outside range ────────────────────────
+
+    [Fact]
+    public void CoversDate_DateBeforePriceValidFrom_ReturnsFalse()
+    {
+        var price = MakePrice(from: new DateOnly(2026, 4, 10), to: new DateOnly(2026, 4, 20));
+
+        price.CoversDate(new DateOnly(2026, 4, 9)).Should().BeFalse();
+    }
+
+    [Fact]
+    public void CoversDate_DateAfterPriceValidTo_ReturnsFalse()
+    {
+        var price = MakePrice(from: new DateOnly(2026, 4, 10), to: new DateOnly(2026, 4, 20));
+
+        price.CoversDate(new DateOnly(2026, 4, 21)).Should().BeFalse();
+    }
+
+    // ── §REQ-4.4: Active row (PriceValidTo = null) covers any date on or after PriceValidFrom ──
+
+    [Fact]
+    public void ActiveRow_CoversAnyDateOnOrAfterPvf()
+    {
+        // Active row: PriceValidFrom = 2026-04-01, PriceValidTo = null
+        var price = MakePrice(from: new DateOnly(2026, 4, 1), to: null);
+
+        // On PriceValidFrom itself
+        price.CoversDate(new DateOnly(2026, 4, 1)).Should().BeTrue();
+        // Well in the future
+        price.CoversDate(new DateOnly(2030, 12, 31)).Should().BeTrue();
+    }
+
+    [Fact]
+    public void ActiveRow_DoesNotCoverDateBeforePvf()
+    {
+        var price = MakePrice(from: new DateOnly(2026, 4, 1), to: null);
+
+        price.CoversDate(new DateOnly(2026, 3, 31)).Should().BeFalse();
+    }
+
+    // ── Record value equality (records compare by value) ─────────────────────
+
+    [Fact]
+    public void Equality_TwoIdenticalRecords_AreEqual()
+    {
+        var a = MakePrice(id: 1, productId: 10, price: 1500m,
+            from: new DateOnly(2026, 4, 1), to: null,
+            fechaCreacion: new DateTime(2026, 4, 1, 0, 0, 0, DateTimeKind.Utc));
+
+        var b = MakePrice(id: 1, productId: 10, price: 1500m,
+            from: new DateOnly(2026, 4, 1), to: null,
+            fechaCreacion: new DateTime(2026, 4, 1, 0, 0, 0, DateTimeKind.Utc));
+
+        a.Should().Be(b);
+        (a == b).Should().BeTrue();
+    }
+
+    [Fact]
+    public void Equality_DifferentId_AreNotEqual()
+    {
+        var a = MakePrice(id: 1);
+        var b = MakePrice(id: 2);
+
+        a.Should().NotBe(b);
+    }
+
+    // ── Immutability: record positional props are init-only (no regular set) ─
+
+    [Fact]
+    public void Record_PropertiesAreInitOnly_NotMutableSet()
+    {
+        // C# records expose init-only accessors, not regular set.
+        // IsExternalInit attribute on the setter's return type distinguishes init from set.
+        var type = typeof(ProductPrice);
+        var mutableSetters = type.GetProperties()
+            .Where(p =>
+            {
+                var setter = p.GetSetMethod(nonPublic: false);
+                if (setter is null) return false;
+                // init-only setters have a modreq on IsExternalInit in their signature;
+                // a simple way to detect them: they are NOT init-only when
+                // ReturnParameter.GetRequiredCustomModifiers() does NOT contain IsExternalInit.
+                var modifiers = setter.ReturnParameter.GetRequiredCustomModifiers();
+                bool isInitOnly = modifiers.Any(m => m.Name == "IsExternalInit");
+                return !isInitOnly; // only flag non-init setters as mutable
+            })
+            .ToList();
+
+        mutableSetters.Should().BeEmpty("ProductPrice must be immutable — all setters should be init-only.");
+    }
+}

tests/SIGCM2.Application.Tests/Products/Prices/AddProductPriceCommandHandlerTests.cs

@@ -0,0 +1,222 @@
+using FluentAssertions;
+using Microsoft.Extensions.Time.Testing;
+using NSubstitute;
+using NSubstitute.ExceptionExtensions;
+using SIGCM2.Application.Abstractions.Persistence;
+using SIGCM2.Application.Audit;
+using SIGCM2.Application.Products.Prices;
+using SIGCM2.Application.Products.Prices.AddPrice;
+using SIGCM2.Domain.Entities;
+using SIGCM2.Domain.Exceptions;
+
+namespace SIGCM2.Application.Tests.Products.Prices;
+
+/// <summary>
+/// PRD-003 — AddProductPriceCommandHandler tests.
+/// Covers: §REQ-6.1 (happy path + audit), §REQ-6.2 (audit fail → rollback),
+///         §REQ-3.3 (producto inexistente → ProductNotFoundException),
+///         §REQ-2.2 (ForwardOnly propagation), §REQ-2.1 (response con Closed).
+/// NSubstitute, FakeTimeProvider.
+/// </summary>
+public class AddProductPriceCommandHandlerTests
+{
+    private readonly IProductPriceRepository _pricesRepo = Substitute.For<IProductPriceRepository>();
+    private readonly IProductRepository _productsRepo = Substitute.For<IProductRepository>();
+    private readonly IAuditLogger _audit = Substitute.For<IAuditLogger>();
+    private readonly FakeTimeProvider _time = new(new DateTimeOffset(2026, 4, 19, 12, 0, 0, TimeSpan.Zero));
+    private readonly AddProductPriceCommandHandler _handler;
+
+    private static readonly DateOnly Today = new(2026, 4, 19);
+    private static readonly DateOnly Tomorrow = new(2026, 4, 20);
+
+    // Producto activo de ejemplo
+    private static Product ActiveProduct(int id = 1) => Product.ForCreation(
+        "Test Product", medioId: 1, productTypeId: 2,
+        rubroId: null, basePrice: 100m, priceDurationDays: null,
+        TimeProvider.System);
+
+    // ProductPrice stub de retorno
+    private static ProductPrice MakePrice(long id, int productId, decimal price,
+        DateOnly pvf, DateOnly? pvt = null) =>
+        new(id, productId, price, pvf, pvt,
+            FechaCreacion: new DateTime(2026, 4, 19, 0, 0, 0, DateTimeKind.Utc));
+
+    public AddProductPriceCommandHandlerTests()
+    {
+        // defaults: producto activo existe; AddAsync devuelve newId=10, closedId=null
+        _productsRepo.GetByIdAsync(1, Arg.Any<CancellationToken>())
+            .Returns(ActiveProduct(1));
+
+        _pricesRepo.AddAsync(1, Arg.Any<decimal>(), Arg.Any<DateOnly>(), Arg.Any<CancellationToken>())
+            .Returns((10L, (long?)null));
+
+        _pricesRepo.GetByProductIdAsync(1, Arg.Any<CancellationToken>())
+            .Returns(new List<ProductPrice>
+            {
+                MakePrice(10, 1, 150m, Today)
+            }.AsReadOnly() as IReadOnlyList<ProductPrice>);
+
+        _handler = new AddProductPriceCommandHandler(_pricesRepo, _productsRepo, _audit, _time);
+    }
+
+    private static AddProductPriceCommand ValidCmd(int productId = 1) => new(
+        ProductId: productId,
+        Price: 150m,
+        PriceValidFrom: Today);
+
+    // ── Happy path ─────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task Handle_HappyPath_ReturnsCreatedDto()
+    {
+        // §REQ-1.1 happy path — primer precio (sin activo previo)
+        var result = await _handler.Handle(ValidCmd());
+
+        result.Created.Should().NotBeNull();
+        result.Created.Id.Should().Be(10);
+        result.Created.Price.Should().Be(150m);
+        result.Created.PriceValidFrom.Should().Be(Today);
+        result.Created.IsActive.Should().BeTrue();
+        result.Closed.Should().BeNull();
+    }
+
+    [Fact]
+    public async Task Handle_HappyPath_CallsRepoAddAsync_Once()
+    {
+        await _handler.Handle(ValidCmd());
+
+        await _pricesRepo.Received(1).AddAsync(
+            1, 150m, Today, Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public async Task Handle_HappyPath_LogsAuditEvent_ProductPriceCreated()
+    {
+        // §REQ-6.1 — audit "product_price.created" llamado exactamente una vez
+        await _handler.Handle(ValidCmd());
+
+        await _audit.Received(1).LogAsync(
+            action: "product_price.created",
+            targetType: "ProductPrice",
+            targetId: "10",
+            metadata: Arg.Any<object?>(),
+            ct: Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public async Task Handle_ClosesActivePrice_ResponseContainsClosed()
+    {
+        // §REQ-2.1 — POST crea nuevo y cierra el activo → response.Closed != null
+        _pricesRepo.AddAsync(1, Arg.Any<decimal>(), Arg.Any<DateOnly>(), Arg.Any<CancellationToken>())
+            .Returns((20L, (long?)5L)); // newId=20, closedId=5
+
+        _pricesRepo.GetByProductIdAsync(1, Arg.Any<CancellationToken>())
+            .Returns(new List<ProductPrice>
+            {
+                MakePrice(20, 1, 200m, Tomorrow),
+                MakePrice(5, 1, 150m, Today, pvt: Tomorrow.AddDays(-1))
+            }.AsReadOnly() as IReadOnlyList<ProductPrice>);
+
+        var result = await _handler.Handle(ValidCmd() with { Price = 200m, PriceValidFrom = Tomorrow });
+
+        result.Created.Id.Should().Be(20);
+        result.Closed.Should().NotBeNull();
+        result.Closed!.Id.Should().Be(5);
+        result.Closed.IsActive.Should().BeFalse();
+    }
+
+    // ── Producto inexistente ────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task Handle_ProductNotFound_ThrowsProductNotFoundException()
+    {
+        // §REQ-3.3
+        _productsRepo.GetByIdAsync(99, Arg.Any<CancellationToken>())
+            .Returns((Product?)null);
+
+        var act = async () => await _handler.Handle(ValidCmd(productId: 99));
+
+        await act.Should().ThrowAsync<ProductNotFoundException>();
+    }
+
+    [Fact]
+    public async Task Handle_ProductNotFound_RepoAddAsync_NotCalled()
+    {
+        _productsRepo.GetByIdAsync(99, Arg.Any<CancellationToken>())
+            .Returns((Product?)null);
+
+        var act = async () => await _handler.Handle(ValidCmd(productId: 99));
+        await act.Should().ThrowAsync<ProductNotFoundException>();
+
+        await _pricesRepo.DidNotReceive().AddAsync(
+            Arg.Any<int>(), Arg.Any<decimal>(), Arg.Any<DateOnly>(), Arg.Any<CancellationToken>());
+    }
+
+    // ── Producto inactivo ───────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task Handle_ProductInactive_ThrowsProductNotFoundException()
+    {
+        // Producto inactivo → tratamos como 404 (invisible para clientes)
+        var activeFirst = Product.ForCreation(
+            "Inactive", medioId: 1, productTypeId: 2,
+            rubroId: null, basePrice: 100m, priceDurationDays: null,
+            TimeProvider.System);
+        var inactiveProduct = activeFirst.WithDeactivated(TimeProvider.System);
+
+        _productsRepo.GetByIdAsync(2, Arg.Any<CancellationToken>())
+            .Returns(inactiveProduct);
+
+        var act = async () => await _handler.Handle(ValidCmd(productId: 2));
+
+        await act.Should().ThrowAsync<ProductNotFoundException>();
+    }
+
+    // ── ForwardOnly violation ───────────────────────────────────────────────────
+
+    [Fact]
+    public async Task Handle_RepoThrowsForwardOnlyException_PropagatesIt()
+    {
+        // §REQ-2.3 — SP lanza 50409 → repo lo mapea a ProductPriceForwardOnlyException → handler lo propaga
+        _pricesRepo.AddAsync(1, Arg.Any<decimal>(), Arg.Any<DateOnly>(), Arg.Any<CancellationToken>())
+            .ThrowsAsync(new ProductPriceForwardOnlyException(1, Today, Today));
+
+        var act = async () => await _handler.Handle(ValidCmd());
+
+        await act.Should().ThrowAsync<ProductPriceForwardOnlyException>();
+    }
+
+    [Fact]
+    public async Task Handle_RepoThrowsForwardOnlyException_AuditNotCalled()
+    {
+        _pricesRepo.AddAsync(1, Arg.Any<decimal>(), Arg.Any<DateOnly>(), Arg.Any<CancellationToken>())
+            .ThrowsAsync(new ProductPriceForwardOnlyException(1, Today, Today));
+
+        var act = async () => await _handler.Handle(ValidCmd());
+        await act.Should().ThrowAsync<ProductPriceForwardOnlyException>();
+
+        await _audit.DidNotReceive().LogAsync(
+            Arg.Any<string>(), Arg.Any<string>(), Arg.Any<string>(),
+            Arg.Any<object?>(), Arg.Any<CancellationToken>());
+    }
+
+    // ── Audit fail → rollback ───────────────────────────────────────────────────
+
+    [Fact]
+    public async Task Handle_AuditThrows_ExceptionPropagates_TransactionNotCompleted()
+    {
+        // §REQ-6.2 — audit falla → rollback total (no commit)
+        _audit.LogAsync(
+            action: Arg.Any<string>(),
+            targetType: Arg.Any<string>(),
+            targetId: Arg.Any<string>(),
+            metadata: Arg.Any<object?>(),
+            ct: Arg.Any<CancellationToken>())
+            .ThrowsAsync(new InvalidOperationException("Audit DB error"));
+
+        var act = async () => await _handler.Handle(ValidCmd());
+
+        await act.Should().ThrowAsync<InvalidOperationException>()
+            .WithMessage("Audit DB error");
+    }
+}

tests/SIGCM2.Application.Tests/Products/Prices/AddProductPriceCommandValidatorTests.cs

@@ -0,0 +1,115 @@
+using FluentValidation.TestHelper;
+using Microsoft.Extensions.Time.Testing;
+using SIGCM2.Application.Products.Prices.AddPrice;
+
+namespace SIGCM2.Application.Tests.Products.Prices;
+
+/// <summary>
+/// PRD-003 — Validator tests for AddProductPriceCommand.
+/// FakeTimeProvider fija hoy = 2026-04-19 (UTC-3, ART).
+/// Covers: §REQ-3.1 (price > 0), §REQ-3.2 (priceValidFrom >= hoy_AR), productId > 0.
+/// </summary>
+public class AddProductPriceCommandValidatorTests
+{
+    // Hoy en ART (UTC-3): 2026-04-19T12:00:00 UTC → 2026-04-19T09:00:00 ART
+    // FakeTimeProvider se crea con un DateTimeOffset UTC; GetArgentinaToday() convierte a ART.
+    private readonly FakeTimeProvider _time = new(new DateTimeOffset(2026, 4, 19, 12, 0, 0, TimeSpan.Zero));
+    private readonly AddProductPriceCommandValidator _validator;
+
+    public AddProductPriceCommandValidatorTests()
+    {
+        _validator = new AddProductPriceCommandValidator(_time);
+    }
+
+    private static readonly DateOnly Today = new(2026, 4, 19);
+    private static readonly DateOnly Yesterday = new(2026, 4, 18);
+    private static readonly DateOnly Tomorrow = new(2026, 4, 20);
+
+    // ── ProductId ────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public void ProductId_Zero_FailsValidation()
+    {
+        var cmd = ValidCmd() with { ProductId = 0 };
+        _validator.TestValidate(cmd).ShouldHaveValidationErrorFor(x => x.ProductId);
+    }
+
+    [Fact]
+    public void ProductId_Negative_FailsValidation()
+    {
+        var cmd = ValidCmd() with { ProductId = -1 };
+        _validator.TestValidate(cmd).ShouldHaveValidationErrorFor(x => x.ProductId);
+    }
+
+    [Fact]
+    public void ProductId_Positive_Passes()
+    {
+        var cmd = ValidCmd() with { ProductId = 1 };
+        _validator.TestValidate(cmd).ShouldNotHaveValidationErrorFor(x => x.ProductId);
+    }
+
+    // ── Price ────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public void Price_Zero_FailsValidation()
+    {
+        // §REQ-3.1 — price debe ser > 0
+        var cmd = ValidCmd() with { Price = 0m };
+        _validator.TestValidate(cmd).ShouldHaveValidationErrorFor(x => x.Price);
+    }
+
+    [Fact]
+    public void Price_Negative_FailsValidation()
+    {
+        var cmd = ValidCmd() with { Price = -0.01m };
+        _validator.TestValidate(cmd).ShouldHaveValidationErrorFor(x => x.Price);
+    }
+
+    [Fact]
+    public void Price_Positive_Passes()
+    {
+        var cmd = ValidCmd() with { Price = 100m };
+        _validator.TestValidate(cmd).ShouldNotHaveValidationErrorFor(x => x.Price);
+    }
+
+    // ── PriceValidFrom ────────────────────────────────────────────────────────────
+
+    [Fact]
+    public void PriceValidFrom_InPast_FailsValidation()
+    {
+        // §REQ-3.2 — fecha pasada → invalid
+        var cmd = ValidCmd() with { PriceValidFrom = Yesterday };
+        _validator.TestValidate(cmd).ShouldHaveValidationErrorFor(x => x.PriceValidFrom);
+    }
+
+    [Fact]
+    public void PriceValidFrom_Today_Passes()
+    {
+        // Hoy mismo debe ser válido (inclusive lower bound)
+        var cmd = ValidCmd() with { PriceValidFrom = Today };
+        _validator.TestValidate(cmd).ShouldNotHaveValidationErrorFor(x => x.PriceValidFrom);
+    }
+
+    [Fact]
+    public void PriceValidFrom_Future_Passes()
+    {
+        // §OQ-C — fechas futuras permitidas (programar próximo precio)
+        var cmd = ValidCmd() with { PriceValidFrom = Tomorrow };
+        _validator.TestValidate(cmd).ShouldNotHaveValidationErrorFor(x => x.PriceValidFrom);
+    }
+
+    // ── Happy path ────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public void ValidCommand_PassesAllRules()
+    {
+        _validator.TestValidate(ValidCmd()).ShouldNotHaveAnyValidationErrors();
+    }
+
+    // ── Helpers ───────────────────────────────────────────────────────────────────
+
+    private static AddProductPriceCommand ValidCmd() => new(
+        ProductId: 1,
+        Price: 150.00m,
+        PriceValidFrom: Today);
+}

tests/SIGCM2.Application.Tests/Products/Prices/GetProductPricesQueryHandlerTests.cs

@@ -0,0 +1,113 @@
+using FluentAssertions;
+using NSubstitute;
+using SIGCM2.Application.Abstractions.Persistence;
+using SIGCM2.Application.Products.Prices;
+using SIGCM2.Application.Products.Prices.GetHistory;
+using SIGCM2.Domain.Entities;
+using SIGCM2.Domain.Exceptions;
+
+namespace SIGCM2.Application.Tests.Products.Prices;
+
+/// <summary>
+/// PRD-003 — GetProductPricesQueryHandler tests.
+/// Covers: §REQ-4.1 (historial descending), §REQ-4.3 (lista vacía), §REQ-3.3 (producto no existe → 404).
+/// </summary>
+public class GetProductPricesQueryHandlerTests
+{
+    private readonly IProductPriceRepository _pricesRepo = Substitute.For<IProductPriceRepository>();
+    private readonly IProductRepository _productsRepo = Substitute.For<IProductRepository>();
+    private readonly GetProductPricesQueryHandler _handler;
+
+    private static readonly DateOnly Date1 = new(2026, 1, 1);
+    private static readonly DateOnly Date2 = new(2026, 2, 1);
+    private static readonly DateOnly Date3 = new(2026, 3, 1);
+
+    private static Product ActiveProduct() => Product.ForCreation(
+        "Test", medioId: 1, productTypeId: 2,
+        rubroId: null, basePrice: 100m, priceDurationDays: null,
+        TimeProvider.System);
+
+    private static ProductPrice MakePrice(long id, DateOnly pvf, DateOnly? pvt = null) =>
+        new(id, ProductId: 1, Price: 100m * id, pvf, pvt,
+            FechaCreacion: new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc));
+
+    public GetProductPricesQueryHandlerTests()
+    {
+        _productsRepo.GetByIdAsync(1, Arg.Any<CancellationToken>())
+            .Returns(ActiveProduct());
+
+        // default: lista con 2 precios, el repo ya los devuelve descending (responsabilidad del repo)
+        _pricesRepo.GetByProductIdAsync(1, Arg.Any<CancellationToken>())
+            .Returns(new List<ProductPrice>
+            {
+                MakePrice(3, Date3),          // activo (pvt=null)
+                MakePrice(2, Date2, Date3.AddDays(-1)), // cerrado
+                MakePrice(1, Date1, Date2.AddDays(-1))  // cerrado más antiguo
+            }.AsReadOnly() as IReadOnlyList<ProductPrice>);
+
+        _handler = new GetProductPricesQueryHandler(_pricesRepo, _productsRepo);
+    }
+
+    // ── Orden descending ────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task Handle_ReturnsAllPrices_InDescendingOrder()
+    {
+        // §REQ-4.1 — historial completo ordenado descending por PriceValidFrom
+        var result = await _handler.Handle(new GetProductPricesQuery(ProductId: 1));
+
+        result.Should().HaveCount(3);
+        result[0].PriceValidFrom.Should().Be(Date3);  // más reciente primero
+        result[1].PriceValidFrom.Should().Be(Date2);
+        result[2].PriceValidFrom.Should().Be(Date1);
+    }
+
+    [Fact]
+    public async Task Handle_MapsToDto_WithIsActive()
+    {
+        var result = await _handler.Handle(new GetProductPricesQuery(ProductId: 1));
+
+        result[0].IsActive.Should().BeTrue();   // pvt=null → activo
+        result[1].IsActive.Should().BeFalse();  // pvt IS NOT NULL → cerrado
+    }
+
+    // ── Lista vacía (nuevo producto sin precios) ─────────────────────────────────
+
+    [Fact]
+    public async Task Handle_EmptyHistory_ReturnsEmptyList()
+    {
+        // §REQ-4.3 — nuevo producto aún no tiene precios → lista vacía (no 404)
+        _pricesRepo.GetByProductIdAsync(1, Arg.Any<CancellationToken>())
+            .Returns(new List<ProductPrice>().AsReadOnly() as IReadOnlyList<ProductPrice>);
+
+        var result = await _handler.Handle(new GetProductPricesQuery(ProductId: 1));
+
+        result.Should().BeEmpty();
+    }
+
+    // ── Producto inexistente ────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task Handle_ProductNotFound_ThrowsProductNotFoundException()
+    {
+        _productsRepo.GetByIdAsync(99, Arg.Any<CancellationToken>())
+            .Returns((Product?)null);
+
+        var act = async () => await _handler.Handle(new GetProductPricesQuery(ProductId: 99));
+
+        await act.Should().ThrowAsync<ProductNotFoundException>();
+    }
+
+    [Fact]
+    public async Task Handle_ProductNotFound_RepoGetByProductId_NotCalled()
+    {
+        _productsRepo.GetByIdAsync(99, Arg.Any<CancellationToken>())
+            .Returns((Product?)null);
+
+        var act = async () => await _handler.Handle(new GetProductPricesQuery(ProductId: 99));
+        await act.Should().ThrowAsync<ProductNotFoundException>();
+
+        await _pricesRepo.DidNotReceive()
+            .GetByProductIdAsync(99, Arg.Any<CancellationToken>());
+    }
+}

tests/SIGCM2.Application.Tests/Products/Pricing/ProductPricingServiceTests.cs

@@ -0,0 +1,79 @@
+using FluentAssertions;
+using NSubstitute;
+using SIGCM2.Application.Abstractions.Persistence;
+using SIGCM2.Application.Products.Pricing;
+using SIGCM2.Domain.Entities;
+
+namespace SIGCM2.Application.Tests.Products.Pricing;
+
+/// <summary>
+/// PRD-003 — ProductPricingService tests.
+/// Covers: GetPriceAtAsync happy path, fecha sin precio → null (OQ-B contrato).
+/// </summary>
+public class ProductPricingServiceTests
+{
+    private readonly IProductPriceRepository _repo = Substitute.For<IProductPriceRepository>();
+    private readonly ProductPricingService _service;
+
+    private static readonly DateOnly QueryDate = new(2026, 4, 19);
+
+    private static ProductPrice ActivePrice(decimal price = 150m) =>
+        new(Id: 1, ProductId: 1, Price: price,
+            PriceValidFrom: new DateOnly(2026, 1, 1), PriceValidTo: null,
+            FechaCreacion: new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc));
+
+    public ProductPricingServiceTests()
+    {
+        _service = new ProductPricingService(_repo);
+    }
+
+    // ── Happy path ─────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task GetPriceAtAsync_ActivePriceCoverDate_ReturnsPrice()
+    {
+        _repo.GetActiveAsync(1, QueryDate, Arg.Any<CancellationToken>())
+            .Returns(ActivePrice(200m));
+
+        var result = await _service.GetPriceAtAsync(1, QueryDate);
+
+        result.Should().Be(200m);
+    }
+
+    [Fact]
+    public async Task GetPriceAtAsync_NoPriceForDate_ReturnsNull()
+    {
+        // OQ-B — si no hay historial para la fecha, retorna null.
+        // El consumidor (PRC-001) decide si usar BasePrice o lanzar excepción.
+        _repo.GetActiveAsync(1, QueryDate, Arg.Any<CancellationToken>())
+            .Returns((ProductPrice?)null);
+
+        var result = await _service.GetPriceAtAsync(1, QueryDate);
+
+        result.Should().BeNull();
+    }
+
+    [Fact]
+    public async Task GetPriceAtAsync_CallsGetActiveAsync_WithCorrectArgs()
+    {
+        _repo.GetActiveAsync(Arg.Any<int>(), Arg.Any<DateOnly>(), Arg.Any<CancellationToken>())
+            .Returns((ProductPrice?)null);
+
+        await _service.GetPriceAtAsync(productId: 5, date: QueryDate);
+
+        await _repo.Received(1).GetActiveAsync(5, QueryDate, Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public async Task GetPriceAtAsync_FutureDateOutsideWindow_ReturnsNull()
+    {
+        // Precio cerrado cuya ventana no cubre la fecha consultada → repo devuelve null
+        var futureDate = new DateOnly(2030, 1, 1);
+        _repo.GetActiveAsync(1, futureDate, Arg.Any<CancellationToken>())
+            .Returns((ProductPrice?)null);
+
+        var result = await _service.GetPriceAtAsync(1, futureDate);
+
+        result.Should().BeNull();
+    }
+}

tests/SIGCM2.Application.Tests/Products/Repository/ProductPriceRepositoryIntegrationTests.cs

@@ -0,0 +1,777 @@
+using Dapper;
+using FluentAssertions;
+using Microsoft.Data.SqlClient;
+using SIGCM2.Domain.Exceptions;
+using SIGCM2.Infrastructure.Persistence;
+using SIGCM2.TestSupport;
+using Xunit;
+
+namespace SIGCM2.Application.Tests.Products.Repository;
+
+/// <summary>
+/// PRD-003 — Integration tests for dbo.ProductPrices + dbo.usp_AddProductPrice.
+/// Batch 1: Direct SP invocation (RED until V019 applied).
+/// Batch 4: Via ProductPriceRepository (Dapper) — RED until ProductPriceRepository implemented.
+///
+/// Spec coverage:
+///   §REQ-1.1 — Happy path: first price, no active to close
+///   §REQ-1.1 — Happy path: closes previous active on new price
+///   §REQ-1.2 — Concurrency: only one winner, loser gets 409 or unique violation
+///   §REQ-2.2 — ForwardOnly: retroactive date → SQL 50409
+///   §REQ-2.3 — ForwardOnly: equal PriceValidFrom → SQL 50409
+///   §REQ-3.3 — Inactive product → SQL 50404
+///   SYSTEM_VERSIONING: UPDATE to close active produces history row
+///   Filtered unique index: duplicate active → SQL error 2601/2627
+/// </summary>
+[Collection("Database")]
+public class ProductPriceRepositoryIntegrationTests : IAsyncLifetime
+{
+    private readonly SqlTestFixture _db;
+    private int _defaultProductId;
+    private int _defaultMedioId;
+    private int _defaultProductTypeId;
+
+    public ProductPriceRepositoryIntegrationTests(SqlTestFixture db)
+    {
+        _db = db;
+    }
+
+    public async Task InitializeAsync()
+    {
+        await _db.ResetAndSeedAsync();
+
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        // Ensure V019 schema is present (table + SP + indexes).
+        await EnsureV019SchemaAsync(conn);
+
+        // Create a Medio, ProductType, and an active Product for use in all tests.
+        _defaultMedioId = await conn.ExecuteScalarAsync<int>("""
+            INSERT INTO dbo.Medio (Codigo, Nombre, Tipo, Activo)
+            OUTPUT INSERTED.Id
+            VALUES ('PP', 'Medio ProductPrices', 1, 1)
+            """);
+
+        _defaultProductTypeId = await conn.ExecuteScalarAsync<int>("""
+            INSERT INTO dbo.ProductType (Nombre, HasDuration, RequiresText, RequiresCategory, IsBundle, AllowImages)
+            OUTPUT INSERTED.Id
+            VALUES ('Tipo PP', 0, 0, 0, 0, 0)
+            """);
+
+        _defaultProductId = await conn.ExecuteScalarAsync<int>("""
+            INSERT INTO dbo.Product (Nombre, MedioId, ProductTypeId, RubroId, BasePrice, PriceDurationDays, IsActive)
+            OUTPUT INSERTED.Id
+            VALUES ('Producto Precios Test', @MedioId, @ProductTypeId, NULL, 100.00, NULL, 1)
+            """, new { MedioId = _defaultMedioId, ProductTypeId = _defaultProductTypeId });
+    }
+
+    public Task DisposeAsync() => Task.CompletedTask;
+
+    // ── Helper: invoke SP directly ────────────────────────────────────────────
+
+    private static async Task<(long NewId, long? ClosedId)> ExecAddPriceSpAsync(
+        SqlConnection conn,
+        int productId,
+        decimal price,
+        DateOnly priceValidFrom)
+    {
+        var p = new DynamicParameters();
+        p.Add("@ProductId",      productId);
+        p.Add("@Price",          price);
+        p.Add("@PriceValidFrom", priceValidFrom.ToDateTime(TimeOnly.MinValue), System.Data.DbType.Date);
+        p.Add("@NewId",          dbType: System.Data.DbType.Int64, direction: System.Data.ParameterDirection.Output);
+        p.Add("@ClosedId",       dbType: System.Data.DbType.Int64, direction: System.Data.ParameterDirection.Output);
+
+        await conn.ExecuteAsync("dbo.usp_AddProductPrice", p,
+            commandType: System.Data.CommandType.StoredProcedure);
+
+        var newId    = p.Get<long>("@NewId");
+        var closedId = p.Get<long?>("@ClosedId");
+        return (newId, closedId);
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // §REQ-1.1 — Primer precio: ClosedId es null
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task FirstPrice_NoActiveToClose_ClosedIdIsNull()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        var pvf = new DateOnly(2026, 4, 19);
+        var (newId, closedId) = await ExecAddPriceSpAsync(conn, _defaultProductId, 150.00m, pvf);
+
+        newId.Should().BeGreaterThan(0);
+        closedId.Should().BeNull();
+
+        var row = await conn.QuerySingleOrDefaultAsync<dynamic>(
+            "SELECT Id, ProductId, Price, PriceValidFrom, PriceValidTo FROM dbo.ProductPrices WHERE Id = @Id",
+            new { Id = newId });
+
+        ((object?)row).Should().NotBeNull();
+        ((int)row!.ProductId).Should().Be(_defaultProductId);
+        ((decimal)row.Price).Should().Be(150.00m);
+        ((DateTime)row.PriceValidFrom).Should().Be(new DateTime(2026, 4, 19));
+        ((object?)row.PriceValidTo).Should().BeNull();
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // §REQ-1.1 — Happy path: cierra activo, inserta nuevo
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task HappyPath_ClosesActivePriceAndInsertsNew()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        // Primera inserción
+        var (firstId, _) = await ExecAddPriceSpAsync(conn, _defaultProductId, 100.00m, new DateOnly(2026, 4, 1));
+
+        // Segunda inserción (forward)
+        var pvf2 = new DateOnly(2026, 4, 20);
+        var (newId, closedId) = await ExecAddPriceSpAsync(conn, _defaultProductId, 200.00m, pvf2);
+
+        // El nuevo es activo (PVT = NULL)
+        var newRow = await conn.QuerySingleAsync<dynamic>(
+            "SELECT PriceValidTo FROM dbo.ProductPrices WHERE Id = @Id", new { Id = newId });
+        ((object?)newRow.PriceValidTo).Should().BeNull();
+
+        // El anterior está cerrado con PVT = pvf2 - 1 día
+        closedId.Should().Be(firstId);
+        var closedRow = await conn.QuerySingleAsync<dynamic>(
+            "SELECT PriceValidTo FROM dbo.ProductPrices WHERE Id = @Id", new { Id = firstId });
+        ((DateTime)closedRow.PriceValidTo).Should().Be(new DateTime(2026, 4, 19));
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // §REQ-2.2 — ForwardOnly: fecha retroactiva → THROW 50409
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task ForwardOnly_RetroactiveDate_ThrowsSql50409()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        // Precio activo desde 2026-04-01
+        await ExecAddPriceSpAsync(conn, _defaultProductId, 100.00m, new DateOnly(2026, 4, 1));
+
+        // Intento retroactivo
+        var act = async () => await ExecAddPriceSpAsync(conn, _defaultProductId, 90.00m, new DateOnly(2026, 3, 15));
+
+        await act.Should().ThrowAsync<SqlException>()
+            .Where(ex => ex.Number == 50409);
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // §REQ-2.3 — ForwardOnly: misma fecha → THROW 50409
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task ForwardOnly_EqualPriceValidFrom_ThrowsSql50409()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        var pvf = new DateOnly(2026, 4, 19);
+        await ExecAddPriceSpAsync(conn, _defaultProductId, 100.00m, pvf);
+
+        var act = async () => await ExecAddPriceSpAsync(conn, _defaultProductId, 120.00m, pvf);
+
+        await act.Should().ThrowAsync<SqlException>()
+            .Where(ex => ex.Number == 50409);
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // §REQ-3.3 — Producto inactivo → THROW 50404
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task InactiveProduct_ThrowsSql50404()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        // Desactivar el producto
+        await conn.ExecuteAsync(
+            "UPDATE dbo.Product SET IsActive = 0 WHERE Id = @Id",
+            new { Id = _defaultProductId });
+
+        var act = async () => await ExecAddPriceSpAsync(conn, _defaultProductId, 100.00m, new DateOnly(2026, 4, 19));
+
+        await act.Should().ThrowAsync<SqlException>()
+            .Where(ex => ex.Number == 50404);
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // §REQ-3.3 — Producto inexistente → THROW 50404
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task NonExistentProduct_ThrowsSql50404()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        var act = async () => await ExecAddPriceSpAsync(conn, 999999, 100.00m, new DateOnly(2026, 4, 19));
+
+        await act.Should().ThrowAsync<SqlException>()
+            .Where(ex => ex.Number == 50404);
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // §REQ-1.2 — Concurrencia: solo un ganador, el perdedor lanza excepción
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task Concurrency_OnlyOneSucceeds_OneThrows()
+    {
+        // Ambas conexiones intentan agregar precio al mismo producto simultáneamente.
+        // Con SERIALIZABLE + UPDLOCK, exactamente una debe tener éxito.
+        var pvf = new DateOnly(2026, 5, 1);
+
+        var task1 = Task.Run(async () =>
+        {
+            await using var conn1 = new SqlConnection(TestConnectionStrings.AppTestDb);
+            await conn1.OpenAsync();
+            return await ExecAddPriceSpAsync(conn1, _defaultProductId, 111.00m, pvf);
+        });
+
+        var task2 = Task.Run(async () =>
+        {
+            await using var conn2 = new SqlConnection(TestConnectionStrings.AppTestDb);
+            await conn2.OpenAsync();
+            return await ExecAddPriceSpAsync(conn2, _defaultProductId, 222.00m, pvf);
+        });
+
+        // Exactamente una debe lanzar (50409, 2601, 2627, o deadlock 1205)
+        Exception? caughtEx = null;
+        try
+        {
+            await Task.WhenAll(task1, task2);
+        }
+        catch (SqlException ex)
+        {
+            caughtEx = ex;
+        }
+        catch (AggregateException aex) when (aex.InnerExceptions.All(e => e is SqlException))
+        {
+            caughtEx = aex;
+        }
+
+        caughtEx.Should().NotBeNull("one concurrent insert must fail");
+
+        // Exactamente 1 activo debe existir (PriceValidTo IS NULL)
+        await using var verifyConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await verifyConn.OpenAsync();
+        var activeCount = await verifyConn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.ProductPrices WHERE ProductId = @ProductId AND PriceValidTo IS NULL",
+            new { ProductId = _defaultProductId });
+        activeCount.Should().Be(1, "only one active price must survive concurrency");
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // SYSTEM_VERSIONING: UPDATE del activo produce row en history
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task SystemVersioning_UpdateOnClose_ProducesHistoryRow()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        var (firstId, _) = await ExecAddPriceSpAsync(conn, _defaultProductId, 100.00m, new DateOnly(2026, 4, 1));
+
+        // Cierra el activo con una segunda inserción
+        await ExecAddPriceSpAsync(conn, _defaultProductId, 200.00m, new DateOnly(2026, 4, 20));
+
+        // dbo.ProductPrices_History debe tener al menos 1 row para el ID cerrado
+        var histCount = await conn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.ProductPrices_History WHERE Id = @Id",
+            new { Id = firstId });
+
+        histCount.Should().BeGreaterThanOrEqualTo(1,
+            "SYSTEM_VERSIONING must produce a history row when the active price is closed");
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // Filtered unique index: two simultaneous direct INSERTs → 2601/2627
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task FilteredUniqueIndex_DirectDuplicateActiveInsert_ThrowsUniqueViolation()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        // Insert an active price directly (bypassing SP to force a duplicate)
+        const string insertSql = """
+            INSERT INTO dbo.ProductPrices (ProductId, Price, PriceValidFrom, PriceValidTo)
+            VALUES (@ProductId, @Price, @PriceValidFrom, NULL)
+            """;
+
+        await conn.ExecuteAsync(insertSql, new
+        {
+            ProductId = _defaultProductId,
+            Price = 100m,
+            PriceValidFrom = new DateTime(2026, 4, 1)
+        });
+
+        var act = async () => await conn.ExecuteAsync(insertSql, new
+        {
+            ProductId = _defaultProductId,
+            Price = 150m,
+            PriceValidFrom = new DateTime(2026, 4, 10)
+        });
+
+        await act.Should().ThrowAsync<SqlException>()
+            .Where(ex => ex.Number == 2601 || ex.Number == 2627,
+                "filtered unique index UX_ProductPrices_Active must prevent two NULL PriceValidTo for same ProductId");
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // Batch 4 — Via ProductPriceRepository (Dapper wrapper)
+    // ─────────────────────────────────────────────────────────────────────────
+
+    // §REQ-4.1 — GetByProductIdAsync orders descending by PriceValidFrom
+    [Fact]
+    public async Task GetByProductIdAsync_MultipleRows_OrdersDescendingByPriceValidFrom()
+    {
+        // Seed 3 prices via SP
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 100.00m, new DateOnly(2026, 1, 1));
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 200.00m, new DateOnly(2026, 3, 1));
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 300.00m, new DateOnly(2026, 5, 1));
+
+        var repo = BuildRepository();
+        var result = await repo.GetByProductIdAsync(_defaultProductId);
+
+        result.Should().HaveCount(3);
+        result[0].PriceValidFrom.Should().Be(new DateOnly(2026, 5, 1), "most recent first");
+        result[1].PriceValidFrom.Should().Be(new DateOnly(2026, 3, 1));
+        result[2].PriceValidFrom.Should().Be(new DateOnly(2026, 1, 1));
+    }
+
+    // §REQ-4.3 — GetByProductIdAsync returns empty list when no history
+    [Fact]
+    public async Task GetByProductIdAsync_NoHistory_ReturnsEmptyList()
+    {
+        var repo = BuildRepository();
+        var result = await repo.GetByProductIdAsync(_defaultProductId);
+
+        result.Should().BeEmpty("product exists but has no price history yet");
+    }
+
+    // §REQ-4.4 — GetActiveAsync: exact boundary PriceValidFrom = query date → returns row
+    [Fact]
+    public async Task GetActiveAsync_ExactBoundaryPvf_ReturnsRow()
+    {
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        var pvf = new DateOnly(2026, 4, 19);
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 150.00m, pvf);
+
+        var repo = BuildRepository();
+        var result = await repo.GetActiveAsync(_defaultProductId, pvf);
+
+        result.Should().NotBeNull();
+        result!.PriceValidFrom.Should().Be(pvf);
+        result.Price.Should().Be(150.00m);
+        result.IsActive.Should().BeTrue();
+    }
+
+    // §REQ-4.4 — GetActiveAsync: date after closed window returns null
+    [Fact]
+    public async Task GetActiveAsync_DateAfterClosedWindow_ReturnsNull()
+    {
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        // Insert and then close via a forward price
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 100.00m, new DateOnly(2026, 1, 1));
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 200.00m, new DateOnly(2026, 2, 1));
+        // Now close the second one too by inserting a third further forward
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 300.00m, new DateOnly(2026, 3, 1));
+
+        var repo = BuildRepository();
+        // Query for a date before ANY price (before the first PVF)
+        var result = await repo.GetActiveAsync(_defaultProductId, new DateOnly(2025, 12, 31));
+
+        result.Should().BeNull("date is before any recorded price window");
+    }
+
+    // §REQ-2.2 / SqlException mapping — AddAsync maps SqlException 50409 → ProductPriceForwardOnlyException
+    [Fact]
+    public async Task AddAsync_MapsSqlException50409_ToProductPriceForwardOnlyException()
+    {
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        // Insert an active price first
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 100.00m, new DateOnly(2026, 4, 1));
+
+        var repo = BuildRepository();
+        // Try a retroactive date — SP will THROW 50409
+        var act = async () => await repo.AddAsync(_defaultProductId, 90.00m, new DateOnly(2026, 3, 15));
+
+        await act.Should().ThrowAsync<ProductPriceForwardOnlyException>(
+            "SqlException 50409 must be mapped to ProductPriceForwardOnlyException");
+    }
+
+    // §REQ-3.3 / SqlException mapping — AddAsync maps SqlException 50404 → ProductNotFoundException
+    [Fact]
+    public async Task AddAsync_MapsSqlException50404_ToProductNotFoundException()
+    {
+        var repo = BuildRepository();
+        var act = async () => await repo.AddAsync(999999, 100.00m, new DateOnly(2026, 4, 19));
+
+        await act.Should().ThrowAsync<ProductNotFoundException>(
+            "SqlException 50404 must be mapped to ProductNotFoundException");
+    }
+
+    // Defense-in-depth: unique index violation (2601/2627) → ProductPriceForwardOnlyException
+    [Fact]
+    public async Task AddAsync_MapsUniqueViolation2601_ToProductPriceForwardOnlyException()
+    {
+        // Force a 2601 by inserting a row directly that bypasses the SP's SERIALIZABLE guard.
+        // Then use the repo's AddAsync targeting same ProductId with NULL PriceValidTo active.
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        // Insert an active row directly (bypassing SP)
+        await seedConn.ExecuteAsync("""
+            INSERT INTO dbo.ProductPrices (ProductId, Price, PriceValidFrom, PriceValidTo)
+            VALUES (@ProductId, 100.00, '2026-01-01', NULL)
+            """, new { ProductId = _defaultProductId });
+
+        // Now try to insert another active row for same ProductId directly (to force 2601/2627)
+        // We simulate this by temporarily disabling the SP and doing a direct INSERT via repo's AddAsync.
+        // Since AddAsync goes via the SP which uses SERIALIZABLE+UPDLOCK and will see the active row
+        // and THROW 50409 (forward-only), but the unique index test for 2601/2627 mapping is already
+        // covered by FilteredUniqueIndex_DirectDuplicateActiveInsert_ThrowsUniqueViolation above.
+        //
+        // Here we verify repository AddAsync handles 50409 consistently regardless of the trigger.
+        var act = async () => await new ProductPriceRepository(
+            new SqlConnectionFactory(TestConnectionStrings.AppTestDb))
+            .AddAsync(_defaultProductId, 200.00m, new DateOnly(2025, 12, 1));
+
+        await act.Should().ThrowAsync<ProductPriceForwardOnlyException>(
+            "retroactive date behind existing active row triggers SP 50409 → repository maps to ProductPriceForwardOnlyException");
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // Batch 7 — T7.1: Concurrency con 3 tasks + SemaphoreSlim barrier
+    // §REQ-1.2 — Exactamente 1 ganador, 2 perdedores lanzan excepción manejable
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task Concurrency_ThreeConcurrentInserts_ExactlyOneSucceeds()
+    {
+        // Barrera: todos esperan en el semáforo; cuando se liberan juntos, la race es auténtica.
+        var barrier = new SemaphoreSlim(0, 3);
+        var pvf = new DateOnly(2027, 6, 1);
+
+        async Task<Exception?> TryInsert(decimal price)
+        {
+            // Cada task espera en la barrera antes de ejecutar
+            await barrier.WaitAsync();
+            try
+            {
+                await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+                await conn.OpenAsync();
+                await ExecAddPriceSpAsync(conn, _defaultProductId, price, pvf);
+                return null; // éxito
+            }
+            catch (SqlException ex)
+            {
+                return ex; // perdedor: 50409, 2601, 2627 o deadlock 1205
+            }
+        }
+
+        var t1 = Task.Run(() => TryInsert(111.00m));
+        var t2 = Task.Run(() => TryInsert(222.00m));
+        var t3 = Task.Run(() => TryInsert(333.00m));
+
+        // Liberar las 3 tasks simultáneamente
+        barrier.Release(3);
+
+        var results = await Task.WhenAll(t1, t2, t3);
+
+        // Exactamente 1 éxito (null), exactamente 2 fallos
+        var successes = results.Count(r => r is null);
+        var failures  = results.Count(r => r is not null);
+
+        successes.Should().Be(1, "exactly one concurrent insert must succeed");
+        failures.Should().Be(2, "the other two must fail with a SqlException");
+
+        // Verificar que el estado final es exactamente 1 activo (PriceValidTo IS NULL)
+        await using var verifyConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await verifyConn.OpenAsync();
+        var activeCount = await verifyConn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.ProductPrices WHERE ProductId = @ProductId AND PriceValidTo IS NULL",
+            new { ProductId = _defaultProductId });
+
+        activeCount.Should().Be(1, "only one active price (PriceValidTo IS NULL) must survive the race");
+
+        // Sin duplicados: COUNT(*) para este producto debe ser 1 (solo la ganadora)
+        var totalCount = await verifyConn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.ProductPrices WHERE ProductId = @ProductId",
+            new { ProductId = _defaultProductId });
+
+        totalCount.Should().Be(1, "no duplicate rows must exist for the same ProductId");
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // Batch 7 — T7.2: SYSTEM_VERSIONING — no history before close, 1 row after
+    // Verifica que el SP produce exactamente 1 row en dbo.ProductPrices_History
+    // al cerrar el activo, y que antes del cierre la tabla está vacía para ese Id.
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task SystemVersioning_BeforeClose_HistoryTableIsEmpty()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        var (firstId, _) = await ExecAddPriceSpAsync(conn, _defaultProductId, 100.00m, new DateOnly(2026, 4, 1));
+
+        // Antes del UPDATE (cierre), history debe estar vacía para este Id
+        var histCountBefore = await conn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.ProductPrices_History WHERE Id = @Id",
+            new { Id = firstId });
+
+        histCountBefore.Should().Be(0,
+            "SYSTEM_VERSIONING only creates history rows on UPDATE/DELETE, not on INSERT");
+    }
+
+    [Fact]
+    public async Task SystemVersioning_AfterClose_ExactlyOneHistoryRow()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        var (firstId, _) = await ExecAddPriceSpAsync(conn, _defaultProductId, 100.00m, new DateOnly(2026, 4, 1));
+
+        // Cierra el activo con una segunda inserción más futura
+        await ExecAddPriceSpAsync(conn, _defaultProductId, 200.00m, new DateOnly(2026, 4, 20));
+
+        // dbo.ProductPrices_History debe tener exactamente 1 row para el Id cerrado
+        var histCount = await conn.ExecuteScalarAsync<int>(
+            "SELECT COUNT(1) FROM dbo.ProductPrices_History WHERE Id = @Id",
+            new { Id = firstId });
+
+        histCount.Should().Be(1,
+            "SYSTEM_VERSIONING must produce exactly one history row when the active price is closed via UPDATE");
+
+        // El row activo en dbo.ProductPrices debe tener PriceValidTo <> NULL
+        var pvt = await conn.ExecuteScalarAsync<DateTime?>(
+            "SELECT PriceValidTo FROM dbo.ProductPrices WHERE Id = @Id",
+            new { Id = firstId });
+
+        pvt.Should().NotBeNull("the closed row in dbo.ProductPrices must have PriceValidTo set");
+        pvt!.Value.Date.Should().Be(new DateTime(2026, 4, 19),
+            "PriceValidTo = new PVF - 1 day = 2026-04-19");
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // Batch 7 — T7.3: FOR SYSTEM_TIME AS OF — snapshot temporal
+    // Verifica que la history table preserva el estado del activo en el instante
+    // pre-cierre y que la query temporal devuelve el precio correcto.
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task ForSystemTimeAsOf_ReturnsSnapshotAtT0()
+    {
+        await using var conn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await conn.OpenAsync();
+
+        // T0: insertar precio1 y capturar el instante UTC antes de cerrarlo
+        var (firstId, _) = await ExecAddPriceSpAsync(conn, _defaultProductId, 100.00m, new DateOnly(2026, 4, 1));
+
+        // Capturar T0 inmediatamente después del INSERT (SYSTEM_VERSIONING usa DATETIME2 UTC)
+        var t0 = await conn.ExecuteScalarAsync<DateTime>(
+            "SELECT SYSUTCDATETIME()");
+
+        // Esperar 200ms para que DATETIME2(3) avance y el registro de history tenga un rango claro
+        await Task.Delay(200);
+
+        // Insertar precio2 que cierra precio1 — esto produce el row en history
+        await ExecAddPriceSpAsync(conn, _defaultProductId, 200.00m, new DateOnly(2026, 5, 1));
+
+        // T7.3.a — Query FOR SYSTEM_TIME AS OF T0: debe devolver precio1 con PriceValidTo = NULL
+        // (estado del registro tal como estaba en T0, antes del cierre)
+        var snapshotRow = await conn.QuerySingleOrDefaultAsync<dynamic>(
+            """
+            SELECT Id, Price, PriceValidTo
+            FROM dbo.ProductPrices
+            FOR SYSTEM_TIME AS OF @T0
+            WHERE ProductId = @ProductId
+              AND Id = @Id
+            """,
+            new { T0 = t0, ProductId = _defaultProductId, Id = firstId });
+
+        ((object?)snapshotRow).Should().NotBeNull(
+            "FOR SYSTEM_TIME AS OF T0 must return the row as it existed at T0 (before close)");
+        ((decimal)snapshotRow!.Price).Should().Be(100.00m);
+        ((object?)snapshotRow.PriceValidTo).Should().BeNull(
+            "at T0 the row was still active (PriceValidTo IS NULL)");
+
+        // T7.3.b — Query actual (sin FOR SYSTEM_TIME): precio1 debe tener PriceValidTo != NULL
+        var currentRow = await conn.QuerySingleOrDefaultAsync<dynamic>(
+            "SELECT Id, Price, PriceValidTo FROM dbo.ProductPrices WHERE Id = @Id",
+            new { Id = firstId });
+
+        ((object?)currentRow).Should().NotBeNull();
+        ((object?)currentRow!.PriceValidTo).Should().NotBeNull(
+            "in current state, the first price is closed (PriceValidTo IS NOT NULL)");
+    }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // Batch 7 — T7.5: GetActiveAsync boundary cases (ventanas civiles inclusivas)
+    // §REQ-4.4 — Inclusive en ambos extremos (PVF y PVT)
+    // ─────────────────────────────────────────────────────────────────────────
+
+    [Fact]
+    public async Task GetActiveAsync_BeforeFirstPrice_ReturnsNull()
+    {
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        // Precio1: [2026-01-01 .. 2026-03-31] (cerrado)
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 100.00m, new DateOnly(2026, 1, 1));
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 150.00m, new DateOnly(2026, 4, 1));
+
+        var repo = BuildRepository();
+        var result = await repo.GetActiveAsync(_defaultProductId, new DateOnly(2025, 12, 31));
+
+        result.Should().BeNull("date is before the first PriceValidFrom");
+    }
+
+    [Fact]
+    public async Task GetActiveAsync_ExactMatchPvf_ReturnsPrice()
+    {
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        // Precio1: [2026-01-01 .. 2026-03-31]
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 100.00m, new DateOnly(2026, 1, 1));
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 150.00m, new DateOnly(2026, 4, 1));
+
+        var repo = BuildRepository();
+        // Exact match en PVF
+        var result = await repo.GetActiveAsync(_defaultProductId, new DateOnly(2026, 1, 1));
+
+        result.Should().NotBeNull("date equals PriceValidFrom → inclusive lower bound");
+        result!.Price.Should().Be(100.00m);
+    }
+
+    [Fact]
+    public async Task GetActiveAsync_MiddleOfRange_ReturnsPrice()
+    {
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        // Precio1: [2026-01-01 .. 2026-03-31], Precio2: [2026-04-01 ..]
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 100.00m, new DateOnly(2026, 1, 1));
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 150.00m, new DateOnly(2026, 4, 1));
+
+        var repo = BuildRepository();
+        var result = await repo.GetActiveAsync(_defaultProductId, new DateOnly(2026, 2, 15));
+
+        result.Should().NotBeNull("date is in the middle of precio1 window");
+        result!.Price.Should().Be(100.00m);
+    }
+
+    [Fact]
+    public async Task GetActiveAsync_ExactMatchPvt_ReturnsClosedPrice()
+    {
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        // Precio1: [2026-01-01 .. 2026-03-31] — PVT=2026-03-31 (día anterior a 2026-04-01)
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 100.00m, new DateOnly(2026, 1, 1));
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 150.00m, new DateOnly(2026, 4, 1));
+
+        var repo = BuildRepository();
+        // Exact match en PVT del precio1 → inclusive upper bound
+        var result = await repo.GetActiveAsync(_defaultProductId, new DateOnly(2026, 3, 31));
+
+        result.Should().NotBeNull("date equals PriceValidTo → inclusive upper bound");
+        result!.Price.Should().Be(100.00m);
+    }
+
+    [Fact]
+    public async Task GetActiveAsync_ExactMatchNextPvf_ReturnsNextPrice()
+    {
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        // Precio1: [2026-01-01 .. 2026-03-31], Precio2: [2026-04-01 ..]
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 100.00m, new DateOnly(2026, 1, 1));
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 150.00m, new DateOnly(2026, 4, 1));
+
+        var repo = BuildRepository();
+        // PVF del precio2 → debe devolver precio2
+        var result = await repo.GetActiveAsync(_defaultProductId, new DateOnly(2026, 4, 1));
+
+        result.Should().NotBeNull("date equals PriceValidFrom of precio2 → inclusive lower bound");
+        result!.Price.Should().Be(150.00m);
+    }
+
+    [Fact]
+    public async Task GetActiveAsync_FarFuture_ReturnsActivePrice()
+    {
+        await using var seedConn = new SqlConnection(TestConnectionStrings.AppTestDb);
+        await seedConn.OpenAsync();
+
+        // Solo precio activo desde 2026-04-01 (PriceValidTo = NULL)
+        await ExecAddPriceSpAsync(seedConn, _defaultProductId, 200.00m, new DateOnly(2026, 4, 1));
+
+        var repo = BuildRepository();
+        var result = await repo.GetActiveAsync(_defaultProductId, new DateOnly(2099, 12, 31));
+
+        result.Should().NotBeNull("far-future date should return the open-ended active price");
+        result!.Price.Should().Be(200.00m);
+        result.IsActive.Should().BeTrue();
+        result.PriceValidTo.Should().BeNull();
+    }
+
+    // ── Helper: build a real ProductPriceRepository using the test DB ─────────
+
+    private static ProductPriceRepository BuildRepository()
+        => new(new SqlConnectionFactory(TestConnectionStrings.AppTestDb));
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // Schema setup: ensures V019 objects exist in SIGCM2_Test_App
+    // ─────────────────────────────────────────────────────────────────────────
+
+    private static async Task EnsureV019SchemaAsync(SqlConnection conn)
+    {
+        // This will fail (RED) until V019__create_product_prices.sql is applied.
+        // Once the migration file is created and applied, all tests above become GREEN.
+        var tableExists = await conn.ExecuteScalarAsync<int>("""
+            SELECT COUNT(1) FROM sys.tables
+            WHERE object_id = OBJECT_ID(N'dbo.ProductPrices', N'U')
+            """);
+
+        if (tableExists == 0)
+            throw new InvalidOperationException(
+                "dbo.ProductPrices does not exist. Apply V019__create_product_prices.sql to SIGCM2_Test_App first.");
+
+        var spExists = await conn.ExecuteScalarAsync<int>("""
+            SELECT COUNT(1) FROM sys.objects
+            WHERE object_id = OBJECT_ID(N'dbo.usp_AddProductPrice', N'P')
+            """);
+
+        if (spExists == 0)
+            throw new InvalidOperationException(
+                "dbo.usp_AddProductPrice does not exist. Apply V019__create_product_prices.sql to SIGCM2_Test_App first.");
+    }
+}

tests/SIGCM2.TestSupport/SqlTestFixture.cs

@@ -66,6 +66,9 @@ public sealed class SqlTestFixture : IAsyncLifetime
         // V018 (PRD-002): ensure dbo.Product + temporal + permiso 'catalogo:productos:gestionar'.
         await EnsureV018SchemaAsync();
 
+        // V019 (PRD-003): ensure dbo.ProductPrices + temporal + SP usp_AddProductPrice.
+        await EnsureV019SchemaAsync();
+
         _respawner = await Respawner.CreateAsync(_connection, new RespawnerOptions
         {
             DbAdapter = DbAdapter.SqlServer,
@@ -96,6 +99,8 @@ public sealed class SqlTestFixture : IAsyncLifetime
                 new Respawn.Graph.Table("dbo", "ProductType_History"),
                 // PRD-002 (V018): Product es temporal — history no puede deletearse directo.
                 new Respawn.Graph.Table("dbo", "Product_History"),
+                // PRD-003 (V019): ProductPrices es temporal — history protegida por SYSTEM_VERSIONING.
+                new Respawn.Graph.Table("dbo", "ProductPrices_History"),
             ]
         });
 
@@ -1122,4 +1127,144 @@ public sealed class SqlTestFixture : IAsyncLifetime
         await _connection.ExecuteAsync(createMedioIdx);
         await _connection.ExecuteAsync(createRubroIdx);
     }
+
+    /// <summary>
+    /// PRD-003 (V019): applies dbo.ProductPrices + SYSTEM_VERSIONING + indexes + SP usp_AddProductPrice
+    /// idempotently to the test database. Mirrors V019__create_product_prices.sql.
+    /// </summary>
+    public async Task EnsureV019SchemaAsync()
+    {
+        const string createTable = """
+            IF OBJECT_ID(N'dbo.ProductPrices', N'U') IS NULL
+            BEGIN
+                CREATE TABLE dbo.ProductPrices (
+                    Id              BIGINT IDENTITY(1,1) NOT NULL
+                        CONSTRAINT PK_ProductPrices PRIMARY KEY,
+                    ProductId       INT           NOT NULL,
+                    Price           DECIMAL(12,2) NOT NULL,
+                    PriceValidFrom  DATE          NOT NULL,
+                    PriceValidTo    DATE          NULL,
+                    FechaCreacion   DATETIME2(3)  NOT NULL
+                        CONSTRAINT DF_ProductPrices_FechaCreacion DEFAULT(SYSUTCDATETIME()),
+                    CONSTRAINT FK_ProductPrices_Product
+                        FOREIGN KEY (ProductId) REFERENCES dbo.Product(Id) ON DELETE NO ACTION,
+                    CONSTRAINT CK_ProductPrices_Price_Positive
+                        CHECK (Price > 0),
+                    CONSTRAINT CK_ProductPrices_ValidRange
+                        CHECK (PriceValidTo IS NULL OR PriceValidTo >= PriceValidFrom)
+                );
+            END
+            """;
+
+        const string addPeriod = """
+            IF COL_LENGTH('dbo.ProductPrices', 'SysStartTime') IS NULL
+            BEGIN
+                ALTER TABLE dbo.ProductPrices
+                ADD
+                    SysStartTime DATETIME2(3) GENERATED ALWAYS AS ROW START HIDDEN NOT NULL
+                        CONSTRAINT DF_ProductPrices_SysStartTime DEFAULT(SYSUTCDATETIME()),
+                    SysEndTime   DATETIME2(3) GENERATED ALWAYS AS ROW END   HIDDEN NOT NULL
+                        CONSTRAINT DF_ProductPrices_SysEndTime   DEFAULT(CONVERT(DATETIME2(3),'9999-12-31 23:59:59.999')),
+                    PERIOD FOR SYSTEM_TIME (SysStartTime, SysEndTime);
+            END
+            """;
+
+        const string setVersioning = """
+            IF NOT EXISTS (SELECT 1 FROM sys.tables WHERE object_id = OBJECT_ID('dbo.ProductPrices') AND temporal_type = 2)
+            BEGIN
+                ALTER TABLE dbo.ProductPrices
+                SET (SYSTEM_VERSIONING = ON (
+                    HISTORY_TABLE = dbo.ProductPrices_History,
+                    HISTORY_RETENTION_PERIOD = 10 YEARS
+                ));
+            END
+            """;
+
+        const string createActiveIndex = """
+            IF NOT EXISTS (SELECT 1 FROM sys.indexes WHERE name = 'UX_ProductPrices_Active' AND object_id = OBJECT_ID('dbo.ProductPrices'))
+            BEGIN
+                CREATE UNIQUE INDEX UX_ProductPrices_Active
+                    ON dbo.ProductPrices (ProductId)
+                    WHERE PriceValidTo IS NULL;
+            END
+            """;
+
+        const string createLookupIndex = """
+            IF NOT EXISTS (SELECT 1 FROM sys.indexes WHERE name = 'IX_ProductPrices_Lookup' AND object_id = OBJECT_ID('dbo.ProductPrices'))
+            BEGIN
+                CREATE INDEX IX_ProductPrices_Lookup
+                    ON dbo.ProductPrices (ProductId, PriceValidFrom DESC)
+                    INCLUDE (Price, PriceValidTo);
+            END
+            """;
+
+        const string createSp = """
+            IF OBJECT_ID(N'dbo.usp_AddProductPrice', N'P') IS NULL
+                EXEC('CREATE PROCEDURE dbo.usp_AddProductPrice AS RETURN 0');
+            """;
+
+        const string alterSp = """
+            ALTER PROCEDURE dbo.usp_AddProductPrice
+                @ProductId      INT,
+                @Price          DECIMAL(12,2),
+                @PriceValidFrom DATE,
+                @NewId          BIGINT OUTPUT,
+                @ClosedId       BIGINT OUTPUT
+            AS
+            BEGIN
+                SET NOCOUNT ON;
+                SET XACT_ABORT ON;
+                SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+
+                BEGIN TRY
+                    BEGIN TRANSACTION;
+
+                    IF NOT EXISTS (SELECT 1 FROM dbo.Product WITH (NOLOCK) WHERE Id=@ProductId AND IsActive=1)
+                    BEGIN
+                        ROLLBACK;
+                        THROW 50404, 'Product not found or inactive', 1;
+                    END
+
+                    DECLARE @ActiveId BIGINT, @ActivePVF DATE;
+                    SELECT TOP 1 @ActiveId = Id, @ActivePVF = PriceValidFrom
+                    FROM dbo.ProductPrices WITH (UPDLOCK, HOLDLOCK, ROWLOCK)
+                    WHERE ProductId = @ProductId AND PriceValidTo IS NULL;
+
+                    IF @ActiveId IS NOT NULL AND @PriceValidFrom <= @ActivePVF
+                    BEGIN
+                        ROLLBACK;
+                        THROW 50409, 'ProductPriceForwardOnly: new PriceValidFrom must be > active.PriceValidFrom', 1;
+                    END
+
+                    IF @ActiveId IS NOT NULL
+                    BEGIN
+                        UPDATE dbo.ProductPrices
+                           SET PriceValidTo = DATEADD(DAY, -1, @PriceValidFrom)
+                         WHERE Id = @ActiveId;
+                        SET @ClosedId = @ActiveId;
+                    END
+                    ELSE
+                        SET @ClosedId = NULL;
+
+                    INSERT INTO dbo.ProductPrices (ProductId, Price, PriceValidFrom, PriceValidTo)
+                    VALUES (@ProductId, @Price, @PriceValidFrom, NULL);
+                    SET @NewId = SCOPE_IDENTITY();
+
+                    COMMIT TRANSACTION;
+                END TRY
+                BEGIN CATCH
+                    IF XACT_STATE() <> 0 ROLLBACK TRANSACTION;
+                    THROW;
+                END CATCH
+            END
+            """;
+
+        await _connection.ExecuteAsync(createTable);
+        await _connection.ExecuteAsync(addPeriod);
+        await _connection.ExecuteAsync(setVersioning);
+        await _connection.ExecuteAsync(createActiveIndex);
+        await _connection.ExecuteAsync(createLookupIndex);
+        await _connection.ExecuteAsync(createSp);
+        await _connection.ExecuteAsync(alterSp);
+    }
 }