diff --git a/core/src/main/scala/app/softnetwork/persistence/message/package.scala b/core/src/main/scala/app/softnetwork/persistence/message/package.scala
index 7816966..0dd3873 100644
--- a/core/src/main/scala/app/softnetwork/persistence/message/package.scala
+++ b/core/src/main/scala/app/softnetwork/persistence/message/package.scala
@@ -153,11 +153,13 @@ package object message {
     */
   trait AuditableCommand extends Command with Auditable {
 
+    type T <: AuditableCommand
+
     var correlationId: Option[String] = None
 
-    override def withCorrelationId(correlationId: String): AuditableCommand = {
+    override def withCorrelationId(correlationId: String): T = {
       this.correlationId = Some(correlationId)
-      this
+      this.asInstanceOf[T]
     }
   }
 
diff --git a/core/src/main/scala/app/softnetwork/persistence/service/Service.scala b/core/src/main/scala/app/softnetwork/persistence/service/Service.scala
index b612e0d..fa15fc3 100644
--- a/core/src/main/scala/app/softnetwork/persistence/service/Service.scala
+++ b/core/src/main/scala/app/softnetwork/persistence/service/Service.scala
@@ -2,7 +2,7 @@ package app.softnetwork.persistence.service
 
 import akka.actor.typed.ActorSystem
 import app.softnetwork.persistence.typed.scaladsl.Patterns
-import app.softnetwork.persistence.message.{Command, CommandResult}
+import app.softnetwork.persistence.message.{AuditableCommand, Command, CommandResult}
 
 import scala.concurrent.{ExecutionContext, Future}
 import scala.reflect.ClassTag
@@ -19,4 +19,21 @@ trait Service[C <: Command, R <: CommandResult] { _: Patterns[C, R] =>
     this ?? (entityId, command)
   }
 
+  /** Story 13.7 — the single shared seam for threading a request/flow `correlationId` onto a
+    * command before dispatch. HTTP `serverLogic` (tapir) runs in a `Future` where MDC does not
+    * survive (C14), so the id must travel as DATA: the endpoint reads it via
+    * `HttpCorrelation.correlationInput` and calls this. No-op for commands that are not
+    * [[AuditableCommand]]. The id then rides the command across the cluster-sharding boundary
+    * (Kryo) and the handler journals it onto the event's `correlation_id` proto field.
+    */
+  def runCorrelated(entityId: String, command: C, correlationId: String)(implicit
+    tTag: ClassTag[C]
+  ): Future[R] = {
+    if (correlationId.nonEmpty) command match {
+      case a: AuditableCommand => a.withCorrelationId(correlationId)
+      case _                   =>
+    }
+    run(entityId, command)
+  }
+
 }