diff --git a/order/src/main/java/com/baiyue/order/dto/OrderSplitDtos.java b/order/src/main/java/com/baiyue/order/dto/OrderSplitDtos.java
new file mode 100644
index 000000000..e374e63b1
--- /dev/null
+++ b/order/src/main/java/com/baiyue/order/dto/OrderSplitDtos.java
@@ -0,0 +1,47 @@
+package com.baiyue.order.dto;
+
+import jakarta.validation.constraints.Min;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Positive;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+/** Order-domain contract consumed by Firstleg when a container pick is settled. */
+public final class OrderSplitDtos {
+    private OrderSplitDtos() {}
+
+    public record CreateRequest(
+        @Positive Long tenantId,
+        @Positive Long parentOrderId,
+        @Positive Long sourceOrderId,
+        @Positive Long loadingPlanId,
+        @Positive Long containerBookingId,
+        @NotNull @Min(1) Integer sourcePackageCount,
+        @NotNull @Min(1) Integer loadedPackageCount,
+        @NotNull @Min(0) Integer remainingPackageCount,
+        @NotNull @Min(0) Integer expectedParentVersion,
+        @NotBlank String idempotencyKey,
+        String operationId,
+        List<QuantityLine> lines,
+        String operatorName
+    ) {}
+
+    public record QuantityLine(@Positive Long sourceDetailId, @NotNull @Min(1) Integer packageCount) {}
+
+    public record Response(
+        Long parentOrderId, String parentOrderNo, Integer parentVersion,
+        Child loadedChild, Child remainderChild, Integer sourcePackageCount,
+        Integer loadedPackageCount, Integer remainingPackageCount,
+        Long loadingPlanId, Long containerBookingId, String idempotencyKey,
+        LocalDateTime createdAt
+    ) {}
+
+    public record Child(Long orderId, String orderNo, Integer splitSequence,
+                        String splitRole, Integer packageCount) {}
+
+    public record Tree(Long parentOrderId, String parentOrderNo, Integer parentVersion,
+                       List<Child> children, Integer allocatedPackageCount,
+                       Integer remainingPackageCount) {}
+}