diff --git a/src/ClaudeDo.Data/Migrations/20260423154708_AddPlanningSupport.cs b/src/ClaudeDo.Data/Migrations/20260423154708_AddPlanningSupport.cs
new file mode 100644
index 0000000..ef24f78
--- /dev/null
+++ b/src/ClaudeDo.Data/Migrations/20260423154708_AddPlanningSupport.cs
@@ -0,0 +1,80 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ClaudeDo.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddPlanningSupport : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "parent_task_id",
+                table: "tasks",
+                type: "TEXT",
+                nullable: true);
+
+            migrationBuilder.AddColumn<DateTime>(
+                name: "planning_finalized_at",
+                table: "tasks",
+                type: "TEXT",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "planning_session_id",
+                table: "tasks",
+                type: "TEXT",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "planning_session_token",
+                table: "tasks",
+                type: "TEXT",
+                nullable: true);
+
+            migrationBuilder.CreateIndex(
+                name: "idx_tasks_parent_task_id",
+                table: "tasks",
+                column: "parent_task_id");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_tasks_tasks_parent_task_id",
+                table: "tasks",
+                column: "parent_task_id",
+                principalTable: "tasks",
+                principalColumn: "id",
+                onDelete: ReferentialAction.Restrict);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_tasks_tasks_parent_task_id",
+                table: "tasks");
+
+            migrationBuilder.DropIndex(
+                name: "idx_tasks_parent_task_id",
+                table: "tasks");
+
+            migrationBuilder.DropColumn(
+                name: "parent_task_id",
+                table: "tasks");
+
+            migrationBuilder.DropColumn(
+                name: "planning_finalized_at",
+                table: "tasks");
+
+            migrationBuilder.DropColumn(
+                name: "planning_session_id",
+                table: "tasks");
+
+            migrationBuilder.DropColumn(
+                name: "planning_session_token",
+                table: "tasks");
+        }
+    }
+}
diff --git a/src/ClaudeDo.Data/Migrations/ClaudeDoDbContextModelSnapshot.cs b/src/ClaudeDo.Data/Migrations/ClaudeDoDbContextModelSnapshot.cs
index eee421b..08926d8 100644
--- a/src/ClaudeDo.Data/Migrations/ClaudeDoDbContextModelSnapshot.cs
+++ b/src/ClaudeDo.Data/Migrations/ClaudeDoDbContextModelSnapshot.cs
@@ -273,6 +273,22 @@ namespace ClaudeDo.Data.Migrations
                         .HasColumnType("TEXT")
                         .HasColumnName("notes");
 
+                    b.Property<string>("ParentTaskId")
+                        .HasColumnType("TEXT")
+                        .HasColumnName("parent_task_id");
+
+                    b.Property<DateTime?>("PlanningFinalizedAt")
+                        .HasColumnType("TEXT")
+                        .HasColumnName("planning_finalized_at");
+
+                    b.Property<string>("PlanningSessionId")
+                        .HasColumnType("TEXT")
+                        .HasColumnName("planning_session_id");
+
+                    b.Property<string>("PlanningSessionToken")
+                        .HasColumnType("TEXT")
+                        .HasColumnName("planning_session_token");
+
                     b.Property<string>("Result")
                         .HasColumnType("TEXT")
                         .HasColumnName("result");
@@ -310,6 +326,9 @@ namespace ClaudeDo.Data.Migrations
                     b.HasIndex("ListId")
                         .HasDatabaseName("idx_tasks_list_id");
 
+                    b.HasIndex("ParentTaskId")
+                        .HasDatabaseName("idx_tasks_parent_task_id");
+
                     b.HasIndex("Status")
                         .HasDatabaseName("idx_tasks_status");
 
@@ -502,7 +521,14 @@ namespace ClaudeDo.Data.Migrations
                         .OnDelete(DeleteBehavior.Cascade)
                         .IsRequired();
 
+                    b.HasOne("ClaudeDo.Data.Models.TaskEntity", "Parent")
+                        .WithMany("Children")
+                        .HasForeignKey("ParentTaskId")
+                        .OnDelete(DeleteBehavior.Restrict);
+
                     b.Navigation("List");
+
+                    b.Navigation("Parent");
                 });
 
             modelBuilder.Entity("ClaudeDo.Data.Models.TaskRunEntity", b =>
@@ -566,6 +592,8 @@ namespace ClaudeDo.Data.Migrations
 
             modelBuilder.Entity("ClaudeDo.Data.Models.TaskEntity", b =>
                 {
+                    b.Navigation("Children");
+
                     b.Navigation("Runs");
 
                     b.Navigation("Subtasks");