8 files changed, 55 insertions, 9 deletions

diff --git a/packages/shared/package.json b/packages/shared/package.json
index ccde705..f49be47 100644
--- a/packages/shared/package.json
+++ b/packages/shared/package.json
@@ -3,6 +3,7 @@
   "version": "0.1.0",
   "private": true,
   "main": "dist/index.cjs",
+  "module": "dist/index.es.js",
   "types": "dist/index.d.ts",
   "scripts": {
     "build": "vite build",
@@ -11,5 +12,9 @@
   "devDependencies": {
     "typescript": "^4.5.4",
     "vite": "^2.7.6"
+  },
+  "dependencies": {
+    "mobx": "^6.3.10",
+    "mobx-state-tree": "^5.1.0"
   }
 }
diff --git a/packages/shared/src/contextBridge/SophieRenderer.ts b/packages/shared/src/contextBridge/SophieRenderer.ts
index 91a0a3c..c878595 100644
--- a/packages/shared/src/contextBridge/SophieRenderer.ts
+++ b/packages/shared/src/contextBridge/SophieRenderer.ts
@@ -1,3 +1,7 @@
+import { SharedStoreListener } from '../stores/SharedStore';
+
 export interface SophieRenderer {
-  buttonClicked(): void;
+  setSharedStoreListener(listener: SharedStoreListener): void;
+
+  buttonClick(): void;
 }
diff --git a/packages/shared/src/index.ts b/packages/shared/src/index.ts
index f95675d..7f192bd 100644
--- a/packages/shared/src/index.ts
+++ b/packages/shared/src/index.ts
@@ -1,3 +1,12 @@
 export type { SophieRenderer } from './contextBridge/SophieRenderer';
 
-export { RendererIpcMessage } from './ipc/RendererIpcMessage';
+export { MainToRendererIpcMessage } from './ipc/MainToRendererIpcMessage';
+export { RendererToMainIpcMessage } from './ipc/RendererToMainIpcMessage';
+
+export type {
+  SharedStore,
+  SharedStoreListener,
+  SharedStoreSnapshotIn,
+  SharedStoreSnapshotOut,
+} from './stores/SharedStore';
+export { sharedStore } from './stores/SharedStore';
diff --git a/packages/shared/src/ipc/MainToRendererIpcMessage.ts b/packages/shared/src/ipc/MainToRendererIpcMessage.ts
new file mode 100644
index 0000000..2ddca80
--- /dev/null
+++ b/packages/shared/src/ipc/MainToRendererIpcMessage.ts
@@ -0,0 +1,4 @@
+export enum MainToRendererIpcMessage {
+  SharedStoreSnapshot = "sophie-shared-store-snapshot",
+  SharedStorePatch = "sophie-shared-store-patch",
+}
diff --git a/packages/shared/src/ipc/RendererIpcMessage.ts b/packages/shared/src/ipc/RendererIpcMessage.ts
deleted file mode 100644
index cfb87ae..0000000
--- a/packages/shared/src/ipc/RendererIpcMessage.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-export enum RendererIpcMessage {
-  ButtonClicked = "button-clicked"
-}
diff --git a/packages/shared/src/ipc/RendererToMainIpcMessage.ts b/packages/shared/src/ipc/RendererToMainIpcMessage.ts
new file mode 100644
index 0000000..c4c682d
--- /dev/null
+++ b/packages/shared/src/ipc/RendererToMainIpcMessage.ts
@@ -0,0 +1,4 @@
+export enum RendererToMainIpcMessage {
+  SharedStoreSnapshotRequest = "sophie-shared-store-snapshot-request",
+  ButtonClick = "sophie-button-click"
+}
diff --git a/packages/shared/src/stores/SharedStore.ts b/packages/shared/src/stores/SharedStore.ts
new file mode 100644
index 0000000..8933bca
--- /dev/null
+++ b/packages/shared/src/stores/SharedStore.ts
@@ -0,0 +1,23 @@
+import {
+  IJsonPatch,
+  Instance,
+  types,
+  SnapshotIn,
+  SnapshotOut,
+} from 'mobx-state-tree';
+
+export const sharedStore = types.model("SharedStore", {
+  clickCount: 0
+});
+
+export interface SharedStore extends Instance<typeof sharedStore> {}
+
+export interface SharedStoreSnapshotIn extends SnapshotIn<typeof sharedStore> {}
+
+export interface SharedStoreSnapshotOut extends SnapshotOut<typeof sharedStore> {}
+
+export interface SharedStoreListener {
+  onSnapshot(snapshot: SharedStoreSnapshotIn): void;
+
+  onPatch(patch: IJsonPatch): void;
+}
diff --git a/packages/shared/vite.config.js b/packages/shared/vite.config.js
index cbebb8a..05ec118 100644
--- a/packages/shared/vite.config.js
+++ b/packages/shared/vite.config.js
@@ -26,15 +26,15 @@ const config = {
     outDir: 'dist',
     lib: {
       entry: 'src/index.ts',
-      formats: ['cjs'],
+      formats: ['cjs', 'es'],
+      fileName: (format) => format === 'cjs' ? 'index.cjs' : `index.${format}.js`,
     },
     rollupOptions: {
       external: [
+        'mobx',
+        'mobx-state-tree',
         ...builtinModules,
       ],
-      output: {
-        entryFileNames: '[name].cjs',
-      },
     },
     emptyOutDir: false, // Do not remove `.d.ts` files.
     brotliSize: false,