diff --git a/src/sequencer/project-sequence-steps.ts b/src/sequencer/project-sequence-steps.ts
index 0391215c..ac8b7c98 100644
--- a/src/sequencer/project-sequence-steps.ts
+++ b/src/sequencer/project-sequence-steps.ts
@@ -8,52 +8,70 @@ import {
 } from "../interactions/interaction-links";
 import type { ProjectScheduleRoutine } from "../scheduler/project-scheduler";
 
-export interface ControlSequenceStep {
+export interface HeldControlSequenceStep {
+  stepClass: "held";
+  type: "controlEffect";
+  effect: ControlEffect;
+}
+
+export interface ImpulseControlSequenceStep {
+  stepClass: "impulse";
   type: "controlEffect";
   effect: ControlEffect;
 }
 
 export interface StartDialogueSequenceStep {
+  stepClass: "impulse";
   type: "startDialogue";
   dialogueId: string;
 }
 
 export interface TeleportPlayerSequenceStep {
+  stepClass: "impulse";
   type: "teleportPlayer";
   targetEntityId: string;
 }
 
 export interface ToggleVisibilitySequenceStep {
+  stepClass: "impulse";
   type: "toggleVisibility";
   targetBrushId: string;
   visible?: boolean;
 }
 
-export type SequenceStep =
-  | ControlSequenceStep
+export type HeldSequenceStep = HeldControlSequenceStep;
+
+export type ImpulseSequenceStep =
+  | ImpulseControlSequenceStep
   | StartDialogueSequenceStep
   | TeleportPlayerSequenceStep
   | ToggleVisibilitySequenceStep;
 
+export type SequenceStep = HeldSequenceStep | ImpulseSequenceStep;
+
 export function cloneSequenceStep(step: SequenceStep): SequenceStep {
   switch (step.type) {
     case "controlEffect":
       return {
+        stepClass: step.stepClass,
         type: "controlEffect",
         effect: cloneControlEffect(step.effect)
       };
     case "startDialogue":
       return {
+        stepClass: "impulse",
         type: "startDialogue",
         dialogueId: step.dialogueId
       };
     case "teleportPlayer":
       return {
+        stepClass: "impulse",
         type: "teleportPlayer",
         targetEntityId: step.targetEntityId
       };
     case "toggleVisibility":
       return {
+        stepClass: "impulse",
         type: "toggleVisibility",
         targetBrushId: step.targetBrushId,
         visible: step.visible
@@ -65,14 +83,15 @@ export function cloneSequenceSteps(steps: SequenceStep[]): SequenceStep[] {
   return steps.map(cloneSequenceStep);
 }
 
-export function getInteractionLinkSequenceSteps(
+export function getInteractionLinkImpulseSteps(
   link: InteractionLink
-): SequenceStep[] {
+): ImpulseSequenceStep[] {
   const controlEffect = getInteractionActionControlEffect(link.action);
 
   if (controlEffect !== null) {
     return [
       {
+        stepClass: "impulse",
         type: "controlEffect",
         effect: controlEffect
       }
@@ -83,6 +102,7 @@ export function getInteractionLinkSequenceSteps(
     case "teleportPlayer":
       return [
         {
+          stepClass: "impulse",
           type: "teleportPlayer",
           targetEntityId: link.action.targetEntityId
         }
@@ -90,6 +110,7 @@ export function getInteractionLinkSequenceSteps(
     case "toggleVisibility":
       return [
         {
+          stepClass: "impulse",
           type: "toggleVisibility",
           targetBrushId: link.action.targetBrushId,
           visible: link.action.visible
@@ -98,6 +119,7 @@ export function getInteractionLinkSequenceSteps(
     case "startDialogue":
       return [
         {
+          stepClass: "impulse",
           type: "startDialogue",
           dialogueId: link.action.dialogueId
         }
@@ -113,11 +135,46 @@ export function getInteractionLinkSequenceSteps(
   }
 }
 
-export function getProjectScheduleRoutineSequenceSteps(
-  routine: ProjectScheduleRoutine
+export function getInteractionLinkSequenceSteps(
+  link: InteractionLink
 ): SequenceStep[] {
+  return getInteractionLinkImpulseSteps(link);
+}
+
+export function getProjectScheduleRoutineHeldSteps(
+  routine: ProjectScheduleRoutine
+): HeldSequenceStep[] {
   return routine.effects.map((effect) => ({
+    stepClass: "held" as const,
     type: "controlEffect" as const,
     effect: cloneControlEffect(effect)
   }));
 }
+
+export function getProjectScheduleRoutineSequenceSteps(
+  routine: ProjectScheduleRoutine
+): SequenceStep[] {
+  return getProjectScheduleRoutineHeldSteps(routine);
+}
+
+export function getHeldSequenceControlEffects(
+  steps: readonly HeldSequenceStep[]
+): ControlEffect[] {
+  return steps
+    .filter((step): step is HeldControlSequenceStep => step.type === "controlEffect")
+    .map((step) => cloneControlEffect(step.effect));
+}
+
+export function findHeldSequenceControlEffect<
+  TType extends ControlEffect["type"]
+>(
+  steps: readonly HeldSequenceStep[],
+  type: TType
+): Extract<ControlEffect, { type: TType }> | null {
+  return (
+    getHeldSequenceControlEffects(steps).find(
+      (effect): effect is Extract<ControlEffect, { type: TType }> =>
+        effect.type === type
+    ) ?? null
+  );
+}