init new sub project, backend

backend/.gitignore

@@ -0,0 +1,2 @@
+/dist/
+/node_modules/

backend/package.json

@@ -0,0 +1,25 @@
+{
+  "name": "imbusy-be",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "build": "esbuild src/index.ts --bundle --platform=node --target=node18 --outfile=dist/index.js",
+    "clean": "rm -rf dist",
+    "watch": "npm run build -- --watch"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "type": "commonjs",
+  "devDependencies": {
+    "@types/aws-lambda": "^8.10.150",
+    "@types/node": "^24.0.3",
+    "esbuild": "^0.25.5",
+    "typescript": "^5.8.3"
+  },
+  "dependencies": {
+    "@aws-sdk/client-apigatewaymanagementapi": "^3.830.0",
+    "aws-sdk": "^2.1692.0"
+  }
+}

backend/src/index.ts

@@ -0,0 +1,48 @@
+import { ApiGatewayManagementApiClient, PostToConnectionCommand } from "@aws-sdk/client-apigatewaymanagementapi";
+import { APIGatewayProxyHandlerV2 } from "aws-lambda";
+
+export const main: APIGatewayProxyHandlerV2 = async (event) => {
+  const body = event.body;
+  const {domainName, stage, connectionId, routeKey} = event.requestContext;
+
+  const apiGateway = new ApiGatewayManagementApiClient({
+    endpoint: `https://${domainName}/${stage}`,
+  });
+
+  console.log("Received event: ", JSON.stringify(event, null, 2));
+
+  try {
+    switch (routeKey) {
+      case '$connect':
+        console.log(`New connection: ${connectionId}`);
+      return { statusCode: 200, body: 'Connected' };
+
+      case '$disconnect':
+        console.log(`Disconnected: ${connectionId}`);
+      return { statusCode: 200, body: 'Disconnected' };
+
+      default:
+        console.log(`Received message: ${body}`);
+      await sendMessageToClient(apiGateway, connectionId, `Echo: ${body}`);
+      return { statusCode: 200, body: `Echoed: ${body}` };
+    }
+  } catch (error) {
+    console.error('Error: ', error);
+    return { statusCode: 500, body: 'Error processing request' };
+  }
+};
+
+// メッセージをクライアントに送信する関数（修正済み）
+const sendMessageToClient = async (apiGateway, connectionId, message) => {
+  try {
+    const command = new PostToConnectionCommand({
+      ConnectionId: connectionId,
+      Data: Buffer.from(message),
+    });
+
+    await apiGateway.send(command);
+    console.log(`Sent message to ${connectionId}: ${message}`);
+  } catch (error) {
+    console.error(`Failed to send message to ${connectionId}:`, error);
+  }
+};

backend/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "module": "commonjs",
+    "strict": true,
+    "esModuleInterop": true,
+    "outDir": "dist",
+    "rootDir": "src"
+  },
+  "include": ["src/**/*"]
+}