Project SetUp

Creating the Project

Run the following commands to create a new directory and initialize it as a Node.js project:

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mkdir effect-http-api
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cd effect-http-api
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pnpm init

Installing Dependencies

Run the following command to install the dependencies:

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pnpm add effect@4.0.0-beta.46 @effect/platform-node@4.0.0-beta.46
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pnpm add -D typescript tsx @types/node

What is @effect/platform-node and why do we need it?

To run an HTTP API, you need a server. Effect has an HTTP server module, but it only defines abstract interfaces for things like servers, requests, and responses. Since we are building a Node.js project, we need something that connects these abstract interfaces to the Node.js runtime. This is where @effect/platform-node comes in. It provides the Node.js-specific implementations of those interfaces, so that Effect’s HTTP server can actually listen on a port and handle requests using Node.js under the hood.

Configuring the Project

Add "type": "module" to your package.json and replace the test script with a dev script as shown below:

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{
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  "name": "effect-http-api",
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  "version": "1.0.0",
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  "description": "",
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  "main": "index.js",
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  "scripts": {
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    "dev": "tsx watch server.ts"
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  },
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  "keywords": [],
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  "author": "",
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  "license": "ISC",
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  "type": "module",
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  "packageManager": "pnpm@10.28.0",
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  "dependencies": {
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    "@effect/platform-node": "4.0.0-beta.46",
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    "effect": "4.0.0-beta.46"
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  },
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  "devDependencies": {
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    "@types/node": "^25.5.1",
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    "tsx": "^4.21.0",
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    "typescript": "^6.0.2"
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  }
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}

To start the dev server, you’ll run pnpm dev, which will run tsx watch server.ts under the hood.

tsx is a TypeScript execution environment for Node.js. Node.js (v22.18.0 and later) can run TypeScript files natively. However, tsx offers additional features like watch mode, which makes it a better fit for development. Watch mode automatically re-runs your script whenever any of its imported files are changed. So every time you save a change, tsx will re-run server.ts for you.

Note that the server.ts file doesn’t exist yet; you’ll create it in a later chapter.

Configuring TypeScript

Create a tsconfig.json file in the project root:

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{
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  "compilerOptions": {
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    "target": "ES2022",
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    "module": "nodenext",
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    "moduleResolution": "nodenext",
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    "strict": true,
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    "skipLibCheck": true,
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    "forceConsistentCasingInFileNames": true,
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    "rootDir": "./ecom",
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    "outDir": "./dist"
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  },
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  "include": ["ecom/**/*.ts"]
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}

Your project setup is now complete.