diff --git a/demo/javascript-demo/client/index.html b/demo/javascript-demo/client/index.html
index 12a5c05..5bacdd3 100644
--- a/demo/javascript-demo/client/index.html
+++ b/demo/javascript-demo/client/index.html
@@ -33,6 +33,7 @@ <h4>This is a demo app using Fullscript.js with a script tag</h4>
       feature.mount("treatment-plan-iframe");
       feature.on("treatmentPlan.activated", mockCallback);
       feature.on("patient.selected", mockCallback);
+      feature.on("order.checkoutStarted", mockCallback);
     }
 
     function mockCallback(data) {
diff --git a/demo/react-demo/src/App.tsx b/demo/react-demo/src/App.tsx
index 8891e84..86c14fc 100644
--- a/demo/react-demo/src/App.tsx
+++ b/demo/react-demo/src/App.tsx
@@ -18,6 +18,10 @@ const App = () => {
     console.log(payload);
   };
 
+  const handleOrderCheckoutStarted = (payload: EventListenerPayload<"order.checkoutStarted">) => {
+    console.log(payload);
+  };
+
   const mountTreatmentPlan = () => {
     //     ################
     //  publicKey: fullscript-js-test-public-key-prac
@@ -40,6 +44,7 @@ const App = () => {
     feature.mount("treatment-plan-iframe");
     feature.on("treatmentPlan.activated", handleTreatmentPlanActivated);
     feature.on("patient.selected", handlePatientSelected);
+    feature.on("order.checkoutStarted", handleOrderCheckoutStarted);
   };
 
   return (
diff --git a/src/feature/eventType.ts b/src/feature/eventType.ts
index 01d7b5e..52a7599 100644
--- a/src/feature/eventType.ts
+++ b/src/feature/eventType.ts
@@ -2,6 +2,7 @@
 const EVENT_TYPES = {
   "treatmentPlan.activated": "treatmentPlan.activated",
   "patient.selected": "patient.selected",
+  "order.checkoutStarted": "order.checkoutStarted",
 };
 
 type EventType = keyof typeof EVENT_TYPES;
@@ -60,10 +61,25 @@ type TreatmentPlanPayload = {
   };
 };
 
+type OrderPayload = {
+  order: {
+    id: string;
+    practitionerPay: boolean;
+    treatmentPlan: TreatmentPlanPayload["treatmentPlan"];
+  };
+};
+
+// Indexing with `E` means adding an entry to EVENT_TYPES without one here is a compile error
+type EventPayloads = {
+  "treatmentPlan.activated": TreatmentPlanPayload;
+  "patient.selected": PatientPayload;
+  "order.checkoutStarted": OrderPayload;
+};
+
 type EventListenerPayload<E extends EventType> = {
   id: string;
   type: E;
-  data: E extends "patient.selected" ? PatientPayload : TreatmentPlanPayload;
+  data: EventPayloads[E];
   createdAt: string;
   clinicId: string;
   oauth: {
@@ -84,6 +100,7 @@ export {
   EventListenerPayload,
   TreatmentPlanPayload,
   PatientPayload,
+  OrderPayload,
   EventType,
   EVENT_TYPES,
 };
diff --git a/src/feature/feature.spec.ts b/src/feature/feature.spec.ts
index 4c27dca..3916880 100644
--- a/src/feature/feature.spec.ts
+++ b/src/feature/feature.spec.ts
@@ -2,6 +2,7 @@ import { Dispatcher, createDispatcher } from "../eventSystem";
 import { FeatureType } from "../feature";
 import { FullscriptOptions } from "../fullscript";
 
+import { EventType } from "./eventType";
 import { FeatureOptions } from "./featureType";
 
 let mockCreateIframe;
@@ -153,44 +154,54 @@ describe("feature", () => {
   });
 
   describe("dispatcher calls", () => {
-    it("calls registerEventListener on the dispatcher when on is called", () => {
-      return import("./feature").then(({ getFeature }) => {
-        const callback = jest.fn();
-        const eventType = "treatmentPlan.activated";
-        dispatcher.registerEventListener = jest.fn();
-        const feature = getFeature(
-          mockFeatureType,
-          mockFeatureOptions,
-          mockFullscriptOptions,
-          dispatcher
-        );
-
-        feature.on(eventType, callback);
-        expect(dispatcher.registerEventListener).toHaveBeenCalledWith(
-          `${mockFrameId}.${eventType}`,
-          callback
-        );
-      });
-    });
-
-    it("calls unregisterEventListener on the dispatcher when off is called", () => {
-      return import("./feature").then(({ getFeature }) => {
-        const callback = jest.fn();
-        const eventType = "treatmentPlan.activated";
-        dispatcher.unregisterEventListener = jest.fn();
-        const feature = getFeature(
-          mockFeatureType,
-          mockFeatureOptions,
-          mockFullscriptOptions,
-          dispatcher
-        );
-
-        feature.off(eventType, callback);
-        expect(dispatcher.unregisterEventListener).toHaveBeenCalledWith(
-          `${mockFrameId}.${eventType}`,
-          callback
-        );
-      });
-    });
+    const eventTypes: EventType[] = [
+      "treatmentPlan.activated",
+      "patient.selected",
+      "order.checkoutStarted",
+    ];
+
+    it.each(eventTypes)(
+      "calls registerEventListener on the dispatcher when on is called with %s",
+      eventType => {
+        return import("./feature").then(({ getFeature }) => {
+          const callback = jest.fn();
+          dispatcher.registerEventListener = jest.fn();
+          const feature = getFeature(
+            mockFeatureType,
+            mockFeatureOptions,
+            mockFullscriptOptions,
+            dispatcher
+          );
+
+          feature.on(eventType, callback);
+          expect(dispatcher.registerEventListener).toHaveBeenCalledWith(
+            `${mockFrameId}.${eventType}`,
+            callback
+          );
+        });
+      }
+    );
+
+    it.each(eventTypes)(
+      "calls unregisterEventListener on the dispatcher when off is called with %s",
+      eventType => {
+        return import("./feature").then(({ getFeature }) => {
+          const callback = jest.fn();
+          dispatcher.unregisterEventListener = jest.fn();
+          const feature = getFeature(
+            mockFeatureType,
+            mockFeatureOptions,
+            mockFullscriptOptions,
+            dispatcher
+          );
+
+          feature.off(eventType, callback);
+          expect(dispatcher.unregisterEventListener).toHaveBeenCalledWith(
+            `${mockFrameId}.${eventType}`,
+            callback
+          );
+        });
+      }
+    );
   });
 });
diff --git a/src/feature/index.ts b/src/feature/index.ts
index 0b8833c..665302a 100644
--- a/src/feature/index.ts
+++ b/src/feature/index.ts
@@ -7,6 +7,7 @@ export type {
   EventListenerPayload,
   TreatmentPlanPayload,
   PatientPayload,
+  OrderPayload,
   EventType,
 } from "./eventType";
 
diff --git a/src/fullscriptJsValidator/fullscriptJsValidator.spec.ts b/src/fullscriptJsValidator/fullscriptJsValidator.spec.ts
index 2f663aa..3d3f346 100644
--- a/src/fullscriptJsValidator/fullscriptJsValidator.spec.ts
+++ b/src/fullscriptJsValidator/fullscriptJsValidator.spec.ts
@@ -72,11 +72,14 @@ describe("fullscriptValidator", () => {
   });
 
   describe("validateFeatureEventType", () => {
-    it("does not throw an error if the featureEventType is valid", () => {
-      expect(() => {
-        validateFeatureEventType("treatmentPlan.activated");
-      }).not.toThrow();
-    });
+    it.each(["treatmentPlan.activated", "patient.selected", "order.checkoutStarted"])(
+      "does not throw an error if the featureEventType is %s",
+      eventType => {
+        expect(() => {
+          validateFeatureEventType(eventType);
+        }).not.toThrow();
+      }
+    );
 
     it("throws an error if the featureEventType is not treatmentPlan or a string", () => {
       const invalidEventType = "cancelled";
diff --git a/src/index.ts b/src/index.ts
index b9b22fd..5d0d401 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -12,6 +12,7 @@ export type {
   EventListenerCallback,
   TreatmentPlanPayload,
   PatientPayload,
+  OrderPayload,
   PatientOptions,
   FeatureOptions,
 } from "./feature";