---
title: Understand the generated web server
description: Explore the TypeScript source, Dockerfile, and Wendy app configuration.
language: typescript
---

First [build and run the server](../../../../guides/tutorials/typescript/simple-web-server/). The template owns the exact generated file contents; the examples below explain their roles.

## Code Breakdown

<Steps>
  <Step>
    ### Generated package.json

    Review the generated `package.json`:

    ```json
    {
      "name": "simple-server",
      "version": "0.1.0",
      "type": "module",
      "scripts": {
        "build": "tsc",
        "start": "node dist/index.js",
        "dev": "tsx watch src/index.ts"
      },
      "dependencies": {
        "express": "^4"
      },
      "devDependencies": {
        "@types/express": "^5",
        "@types/node": "^22",
        "typescript": "^5.7",
        "tsx": "^4"
      },
      "engines": {
        "node": ">=22"
      }
    }
    ```
  </Step>

  <Step>
    ### Generated tsconfig.json

    Review the generated `tsconfig.json`:

    ```json
    {
      "compilerOptions": {
        "target": "ES2022",
        "module": "NodeNext",
        "moduleResolution": "NodeNext",
        "outDir": "./dist",
        "rootDir": "./src",
        "strict": true,
        "esModuleInterop": true,
        "skipLibCheck": true,
        "forceConsistentCasingInFileNames": true,
        "declaration": true
      },
      "include": ["src/**/*"],
      "exclude": ["node_modules", "dist"]
    }
    ```
  </Step>

  <Step>
    ### Generated Web Server

    The generated `src/index.ts` contains the server logic:

    ```typescript
    import express, { Request, Response } from "express";

    const app = express();
    const port = 3000;
    const hostname = process.env.WENDY_HOSTNAME || "0.0.0.0";

    app.use(express.json());

    app.get("/", (_req: Request, res: Response) => {
      console.log("Received request: GET /");
      res.json({ message: "hello-world" });
    });

    app.get("/health", (_req: Request, res: Response) => {
      res.json({ status: "ok" });
    });

    interface CreateItemBody {
      name: string;
      price: number;
    }

    interface ItemResponse {
      id: number;
      name: string;
      price: number;
    }

    app.post(
      "/items",
      (req: Request<{}, ItemResponse, CreateItemBody>, res: Response) => {
        console.log(`Received request: POST /items - ${req.body.name}`);
        const item: ItemResponse = {
          id: 1,
          name: req.body.name,
          price: req.body.price,
        };
        res.status(201).json(item);
      }
    );

    app.listen(port, () => {
      console.log(`Server running on http://${hostname}:${port}`);
    });
    ```

    <Callout type="info">
      **Multiple Routes**: This example includes three routes:
      - `GET /` - Returns `{"message":"hello-world"}`
      - `GET /health` - Returns `{"status":"ok"}` for health checks
      - `POST /items` - Creates an item from a JSON body and echoes it back
    </Callout>
  </Step>

  <Step>
    ### Generated Dockerfile

    The generated project includes a multi-stage Dockerfile:

    ```dockerfile
    FROM node:22-slim AS builder

    WORKDIR /app
    COPY package*.json ./
    RUN npm install

    COPY tsconfig.json ./
    COPY src ./src
    RUN npm run build

    FROM node:22-slim

    WORKDIR /app
    COPY --from=builder /app/dist ./dist
    COPY --from=builder /app/node_modules ./node_modules

    EXPOSE 3000

    CMD ["node", "dist/index.js"]
    ```
  </Step>

  <Step>
    ### Generated wendy.json

    The generated `wendy.json` requests the `network` entitlement and already includes a readiness probe plus a `postStart` hook that opens your browser to the device when the server is ready:

    ```json
    {
        "appId": "simple-server",
        "platform": "linux",
        "version": "0.1.0",
        "entitlements": [
            {
                "type": "network"
            }
        ],
        "readiness": {
            "tcpSocket": { "port": 3000 },
            "timeoutSeconds": 30
        },
        "hooks": {
            "postStart": {
                "cli": "wendy utils open-browser http://${WENDY_HOSTNAME}:3000"
            }
        }
    }
    ```
  </Step>
</Steps>