diff --git a/src/PackageRegistryService/Migrations/20240625140809_NoNullableFields.Designer.cs b/src/PackageRegistryService/Migrations/20240625140809_NoNullableFields.Designer.cs
new file mode 100644
index 0000000..be32fad
--- /dev/null
+++ b/src/PackageRegistryService/Migrations/20240625140809_NoNullableFields.Designer.cs
@@ -0,0 +1,231 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using PackageRegistryService.Models;
+
+#nullable disable
+
+namespace PackageRegistryService.Migrations
+{
+    [DbContext(typeof(ValidationPackageDb))]
+    [Migration("20240625140809_NoNullableFields")]
+    partial class NoNullableFields
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.1")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("PackageRegistryService.Models.PackageContentHash", b =>
+                {
+                    b.Property<string>("PackageName")
+                        .HasColumnType("text");
+
+                    b.Property<int>("PackageMajorVersion")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("PackageMinorVersion")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("PackagePatchVersion")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("PackagePreReleaseVersionSuffix")
+                        .HasColumnType("text");
+
+                    b.Property<string>("PackageBuildMetadataVersionSuffix")
+                        .HasColumnType("text");
+
+                    b.Property<string>("Hash")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("PackageName", "PackageMajorVersion", "PackageMinorVersion", "PackagePatchVersion", "PackagePreReleaseVersionSuffix", "PackageBuildMetadataVersionSuffix");
+
+                    b.ToTable("Hashes");
+                });
+
+            modelBuilder.Entity("PackageRegistryService.Models.PackageDownloads", b =>
+                {
+                    b.Property<string>("PackageName")
+                        .HasColumnType("text");
+
+                    b.Property<int>("PackageMajorVersion")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("PackageMinorVersion")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("PackagePatchVersion")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("PackagePreReleaseVersionSuffix")
+                        .HasColumnType("text");
+
+                    b.Property<string>("PackageBuildMetadataVersionSuffix")
+                        .HasColumnType("text");
+
+                    b.Property<int>("Downloads")
+                        .HasColumnType("integer");
+
+                    b.HasKey("PackageName", "PackageMajorVersion", "PackageMinorVersion", "PackagePatchVersion", "PackagePreReleaseVersionSuffix", "PackageBuildMetadataVersionSuffix");
+
+                    b.ToTable("Downloads");
+                });
+
+            modelBuilder.Entity("PackageRegistryService.Models.ValidationPackage", b =>
+                {
+                    b.Property<string>("Name")
+                        .HasColumnType("text");
+
+                    b.Property<int>("MajorVersion")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("MinorVersion")
+                        .HasColumnType("integer");
+
+                    b.Property<int>("PatchVersion")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("PreReleaseVersionSuffix")
+                        .HasColumnType("text");
+
+                    b.Property<string>("BuildMetadataVersionSuffix")
+                        .HasColumnType("text");
+
+                    b.Property<string>("CQCHookEndpoint")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<byte[]>("PackageContent")
+                        .IsRequired()
+                        .HasColumnType("bytea");
+
+                    b.Property<DateOnly>("ReleaseDate")
+                        .HasColumnType("date");
+
+                    b.Property<string>("ReleaseNotes")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("Summary")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Name", "MajorVersion", "MinorVersion", "PatchVersion", "PreReleaseVersionSuffix", "BuildMetadataVersionSuffix");
+
+                    b.ToTable("ValidationPackages");
+                });
+
+            modelBuilder.Entity("PackageRegistryService.Models.ValidationPackage", b =>
+                {
+                    b.OwnsMany("AVPRIndex.Domain+Author", "Authors", b1 =>
+                        {
+                            b1.Property<string>("ValidationPackageName")
+                                .HasColumnType("text");
+
+                            b1.Property<int>("ValidationPackageMajorVersion")
+                                .HasColumnType("integer");
+
+                            b1.Property<int>("ValidationPackageMinorVersion")
+                                .HasColumnType("integer");
+
+                            b1.Property<int>("ValidationPackagePatchVersion")
+                                .HasColumnType("integer");
+
+                            b1.Property<string>("ValidationPackagePreReleaseVersionSuffix")
+                                .HasColumnType("text");
+
+                            b1.Property<string>("ValidationPackageBuildMetadataVersionSuffix")
+                                .HasColumnType("text");
+
+                            b1.Property<int>("Id")
+                                .ValueGeneratedOnAdd()
+                                .HasColumnType("integer");
+
+                            b1.Property<string>("Affiliation")
+                                .HasColumnType("text");
+
+                            b1.Property<string>("AffiliationLink")
+                                .HasColumnType("text");
+
+                            b1.Property<string>("Email")
+                                .HasColumnType("text");
+
+                            b1.Property<string>("FullName")
+                                .HasColumnType("text");
+
+                            b1.HasKey("ValidationPackageName", "ValidationPackageMajorVersion", "ValidationPackageMinorVersion", "ValidationPackagePatchVersion", "ValidationPackagePreReleaseVersionSuffix", "ValidationPackageBuildMetadataVersionSuffix", "Id");
+
+                            b1.ToTable("ValidationPackages");
+
+                            b1.ToJson("Authors");
+
+                            b1.WithOwner()
+                                .HasForeignKey("ValidationPackageName", "ValidationPackageMajorVersion", "ValidationPackageMinorVersion", "ValidationPackagePatchVersion", "ValidationPackagePreReleaseVersionSuffix", "ValidationPackageBuildMetadataVersionSuffix");
+                        });
+
+                    b.OwnsMany("AVPRIndex.Domain+OntologyAnnotation", "Tags", b1 =>
+                        {
+                            b1.Property<string>("ValidationPackageName")
+                                .HasColumnType("text");
+
+                            b1.Property<int>("ValidationPackageMajorVersion")
+                                .HasColumnType("integer");
+
+                            b1.Property<int>("ValidationPackageMinorVersion")
+                                .HasColumnType("integer");
+
+                            b1.Property<int>("ValidationPackagePatchVersion")
+                                .HasColumnType("integer");
+
+                            b1.Property<string>("ValidationPackagePreReleaseVersionSuffix")
+                                .HasColumnType("text");
+
+                            b1.Property<string>("ValidationPackageBuildMetadataVersionSuffix")
+                                .HasColumnType("text");
+
+                            b1.Property<int>("Id")
+                                .ValueGeneratedOnAdd()
+                                .HasColumnType("integer");
+
+                            b1.Property<string>("Name")
+                                .HasColumnType("text");
+
+                            b1.Property<string>("TermAccessionNumber")
+                                .HasColumnType("text");
+
+                            b1.Property<string>("TermSourceREF")
+                                .HasColumnType("text");
+
+                            b1.HasKey("ValidationPackageName", "ValidationPackageMajorVersion", "ValidationPackageMinorVersion", "ValidationPackagePatchVersion", "ValidationPackagePreReleaseVersionSuffix", "ValidationPackageBuildMetadataVersionSuffix", "Id");
+
+                            b1.ToTable("ValidationPackages");
+
+                            b1.ToJson("Tags");
+
+                            b1.WithOwner()
+                                .HasForeignKey("ValidationPackageName", "ValidationPackageMajorVersion", "ValidationPackageMinorVersion", "ValidationPackagePatchVersion", "ValidationPackagePreReleaseVersionSuffix", "ValidationPackageBuildMetadataVersionSuffix");
+                        });
+
+                    b.Navigation("Authors");
+
+                    b.Navigation("Tags");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/src/PackageRegistryService/Migrations/20240625140809_NoNullableFields.cs b/src/PackageRegistryService/Migrations/20240625140809_NoNullableFields.cs
new file mode 100644
index 0000000..5505d40
--- /dev/null
+++ b/src/PackageRegistryService/Migrations/20240625140809_NoNullableFields.cs
@@ -0,0 +1,54 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace PackageRegistryService.Migrations
+{
+    /// <inheritdoc />
+    public partial class NoNullableFields : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AlterColumn<string>(
+                name: "ReleaseNotes",
+                table: "ValidationPackages",
+                type: "text",
+                nullable: false,
+                defaultValue: "",
+                oldClrType: typeof(string),
+                oldType: "text",
+                oldNullable: true);
+
+            migrationBuilder.AlterColumn<string>(
+                name: "CQCHookEndpoint",
+                table: "ValidationPackages",
+                type: "text",
+                nullable: false,
+                defaultValue: "",
+                oldClrType: typeof(string),
+                oldType: "text",
+                oldNullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AlterColumn<string>(
+                name: "ReleaseNotes",
+                table: "ValidationPackages",
+                type: "text",
+                nullable: true,
+                oldClrType: typeof(string),
+                oldType: "text");
+
+            migrationBuilder.AlterColumn<string>(
+                name: "CQCHookEndpoint",
+                table: "ValidationPackages",
+                type: "text",
+                nullable: true,
+                oldClrType: typeof(string),
+                oldType: "text");
+        }
+    }
+}
diff --git a/src/PackageRegistryService/Migrations/ValidationPackageDbModelSnapshot.cs b/src/PackageRegistryService/Migrations/ValidationPackageDbModelSnapshot.cs
index d196a9f..3a4c989 100644
--- a/src/PackageRegistryService/Migrations/ValidationPackageDbModelSnapshot.cs
+++ b/src/PackageRegistryService/Migrations/ValidationPackageDbModelSnapshot.cs
@@ -100,6 +100,7 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                         .HasColumnType("text");
 
                     b.Property<string>("CQCHookEndpoint")
+                        .IsRequired()
                         .HasColumnType("text");
 
                     b.Property<string>("Description")
@@ -114,6 +115,7 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                         .HasColumnType("date");
 
                     b.Property<string>("ReleaseNotes")
+                        .IsRequired()
                         .HasColumnType("text");
 
                     b.Property<string>("Summary")
diff --git a/src/PackageRegistryService/Models/ValidationPackage.cs b/src/PackageRegistryService/Models/ValidationPackage.cs
index 1a48c5c..eef43a9 100644
--- a/src/PackageRegistryService/Models/ValidationPackage.cs
+++ b/src/PackageRegistryService/Models/ValidationPackage.cs
@@ -81,22 +81,22 @@ public class ValidationPackage
         /// <summary>
         /// 
         /// </summary>
-        public ICollection<AVPRIndex.Domain.OntologyAnnotation>? Tags { get; set; }
+        public ICollection<AVPRIndex.Domain.OntologyAnnotation> Tags { get; set; } = Array.Empty<AVPRIndex.Domain.OntologyAnnotation>();
 
         /// <summary>
         /// 
         /// </summary>
-        public string? ReleaseNotes { get; set; }
+        public string ReleaseNotes { get; set; } = "";
 
         /// <summary>
         /// 
         /// </summary>
-        public string? CQCHookEndpoint { get; set; }
+        public string CQCHookEndpoint { get; set; } = "";
 
         /// <summary>
         /// 
         /// </summary>
-        public ICollection<AVPRIndex.Domain.Author>? Authors { get; set; } // https://www.learnentityframeworkcore.com/relationships#navigation-properties
+        public ICollection<AVPRIndex.Domain.Author> Authors { get; set; } = Array.Empty<AVPRIndex.Domain.Author>();// https://www.learnentityframeworkcore.com/relationships#navigation-properties
 
         /// <summary>
         ///