diff --git a/PuferFishContracts/PuferFishContracts/Infrastructure/IConfigurationDatabase.cs b/PuferFishContracts/PuferFishContracts/Infrastructure/IConfigurationDatabase.cs
new file mode 100644
index 0000000..3407673
--- /dev/null
+++ b/PuferFishContracts/PuferFishContracts/Infrastructure/IConfigurationDatabase.cs
@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace PuferFishContracts.Infrastructure;
+
+public interface IConfigurationDatabase
+{
+    string ConnectionString { get; }
+}
diff --git a/PuferFishContracts/PuferFishDataBase/PuferFishDataBase.csproj b/PuferFishContracts/PuferFishDataBase/PuferFishDataBase.csproj
index 0adc9e6..d38afa4 100644
--- a/PuferFishContracts/PuferFishDataBase/PuferFishDataBase.csproj
+++ b/PuferFishContracts/PuferFishDataBase/PuferFishDataBase.csproj
@@ -6,6 +6,11 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.2" />
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.4" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\PuferFishContracts\PuferFishContracts.csproj" />
   </ItemGroup>
diff --git a/PuferFishContracts/PuferFishDataBase/PuferFishDbContext.cs b/PuferFishContracts/PuferFishDataBase/PuferFishDbContext.cs
new file mode 100644
index 0000000..82d68e4
--- /dev/null
+++ b/PuferFishContracts/PuferFishDataBase/PuferFishDbContext.cs
@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using PuferFishContracts.Infrastructure;
+using PuferFishDataBase.Models;
+
+namespace PuferFishDataBase;
+
+internal class PuferFishDbContext(IConfigurationDatabase configurationDatabase) : DbContext
+{
+    private readonly IConfigurationDatabase? _configurationDatabase = configurationDatabase;
+    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+    {
+        optionsBuilder.UseNpgsql(_configurationDatabase?.ConnectionString, o => o.SetPostgresVersion(12, 2));
+        base.OnConfiguring(optionsBuilder);
+    }
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        base.OnModelCreating(modelBuilder);
+        modelBuilder.Entity<Buyer>().HasIndex(x => x.PhoneNumber).IsUnique();
+        modelBuilder.Entity<Post>()
+            .HasIndex(e => new { e.PostName, e.IsActual })
+            .IsUnique()
+            .HasFilter($"\"{nameof(Post.IsActual)}\" = TRUE");
+        modelBuilder.Entity<Post>()
+            .HasIndex(e => new { e.PostId, e.IsActual })
+            .IsUnique()
+            .HasFilter($"\"{nameof(Post.IsActual)}\" = TRUE");
+        modelBuilder.Entity<Product>()
+            .HasIndex(x => new { x.ProductName, x.IsDeleted })
+            .IsUnique()
+            .HasFilter($"\"{nameof(Product.IsDeleted)}\" = FALSE");
+        modelBuilder.Entity<SaleProduct>().HasKey(x => new {
+            x.SaleId,
+            x.ProductId
+        });
+    }
+
+    public DbSet<Buyer> Buyers { get; set; }
+    public DbSet<Post> Posts { get; set; }
+    public DbSet<Product> Products { get; set; }
+    public DbSet<ProductHistory> ProductHistories { get; set; }
+    public DbSet<Points> Pointss { get; set; }
+    public DbSet<Sale> Sales { get; set; }
+    public DbSet<SaleProduct> SaleProducts { get; set; }
+    public DbSet<Worker> Workers { get; set; }
+}