diff --git a/src/food-market.api/Controllers/Catalog/CounterpartiesController.cs b/src/food-market.api/Controllers/Catalog/CounterpartiesController.cs
index 6ca8c87..4ef9ade 100644
--- a/src/food-market.api/Controllers/Catalog/CounterpartiesController.cs
+++ b/src/food-market.api/Controllers/Catalog/CounterpartiesController.cs
@@ -103,6 +103,23 @@ public async Task<IActionResult> Delete(Guid id, CancellationToken ct)
     {
         var e = await _db.Counterparties.FirstOrDefaultAsync(x => x.Id == id, ct);
         if (e is null) return NotFound();
+
+        // FK-guard: counterparty используется как Supplier в supplies / customer
+        // в retail-sales / default supplier у products. Без явного чека EF
+        // отдаёт 500 «DbUpdateException 23503 violates foreign key constraint»
+        // вместо понятного 409 — пользователь не понимает что чинить.
+        var usedAsSupplier = await _db.Supplies.AnyAsync(s => s.SupplierId == id, ct);
+        var usedAsCustomer = await _db.RetailSales.AnyAsync(s => s.CustomerId == id, ct);
+        var usedAsDefault  = await _db.Products.AnyAsync(p => p.DefaultSupplierId == id, ct);
+        if (usedAsSupplier || usedAsCustomer || usedAsDefault)
+        {
+            return Conflict(new
+            {
+                error = "Нельзя удалить контрагента: он используется в документах или товарах.",
+                usedAsSupplier, usedAsCustomer, usedAsDefault,
+            });
+        }
+
         _db.Counterparties.Remove(e);
         await _db.SaveChangesAsync(ct);
         return NoContent();
diff --git a/src/food-market.api/Controllers/Catalog/ProductsController.cs b/src/food-market.api/Controllers/Catalog/ProductsController.cs
index acdf2ee..bfdf088 100644
--- a/src/food-market.api/Controllers/Catalog/ProductsController.cs
+++ b/src/food-market.api/Controllers/Catalog/ProductsController.cs
@@ -198,6 +198,8 @@ public async Task<ActionResult<ProductDto>> Get(Guid id, CancellationToken ct)
     [HttpPost, Authorize(Roles = "Admin,Storekeeper")]
     public async Task<ActionResult<ProductDto>> Create([FromBody] ProductInput input, CancellationToken ct)
     {
+        if (string.IsNullOrWhiteSpace(input.Name))
+            return BadRequest(new { error = "Название товара обязательно.", field = nameof(input.Name) });
         if (RequiredGuid.FirstMissing(
                 (nameof(input.UnitOfMeasureId), input.UnitOfMeasureId),
                 (nameof(input.ProductGroupId), input.ProductGroupId)) is { } missingFk)
diff --git a/src/food-market.application/Catalog/CatalogDtos.cs b/src/food-market.application/Catalog/CatalogDtos.cs
index 23debef..2e3088f 100644
--- a/src/food-market.application/Catalog/CatalogDtos.cs
+++ b/src/food-market.application/Catalog/CatalogDtos.cs
@@ -85,12 +85,14 @@ public record CounterpartyInput(
 public record ProductBarcodeInput(string Code, BarcodeType Type = BarcodeType.Ean13, bool IsPrimary = false);
 public record ProductPriceInput(Guid PriceTypeId, [Range(0, 1e10)] decimal Amount, Guid CurrencyId);
 public record ProductInput(
-    string Name, string? Article, string? Description,
+    [Required, MinLength(1), StringLength(500)] string Name,
+    [StringLength(500)] string? Article,
+    string? Description,
     Guid UnitOfMeasureId, [Range(0, 100)] decimal? Vat, bool VatEnabled,
     Guid ProductGroupId, Guid? DefaultSupplierId, Guid? CountryOfOriginId,
     bool IsService = false, Packaging Packaging = Packaging.Piece, bool IsMarked = false,
     [Range(0, 1e10)] decimal? MinStock = null, [Range(0, 1e10)] decimal? MaxStock = null,
     [Range(0, 1e10)] decimal? ReferencePrice = null, Guid? PurchaseCurrencyId = null,
-    string? ImageUrl = null,
+    [StringLength(1000)] string? ImageUrl = null,
     IReadOnlyList<ProductPriceInput>? Prices = null,
     IReadOnlyList<ProductBarcodeInput>? Barcodes = null);