clade-local-dev-loop

name	clade-local-dev-loop
description	Set up a fast local development loop for building with the Anthropic API — Use when working with local-dev-loop patterns. hot reload, cost-saving tips, and test patterns. Trigger with "anthropic dev setup", "claude local development", "anthropic test locally", "claude dev workflow".
allowed-tools	Read, Write, Edit, Bash(npm:*), Bash(pip:*)
version	1.0.0
license	MIT
author	Jeremy Longshore <[e-mail]>
tags	["saas","anthropic","claude","development","testing"]
compatibility	Designed for Claude Code

Anthropic Local Dev Loop

Overview

Set up a fast, cheap development workflow for building with Claude.

Prerequisites

• Node.js 18+ or Python 3.10+
• ANTHROPIC_API_KEY environment variable set
• npm or pip package manager

Instructions

Step 1: Project Setup

mkdir my-claude-app && cd my-claude-app
npm init -y
npm install @claude-ai/sdk dotenv tsx

# Create .env (never commit this)
echo 'ANTHROPIC_API_KEY=sk-ant-api03-...' > .env
echo '.env' >> .gitignore

Step 2: Create a Test Script

// src/test-prompt.ts
import 'dotenv/config';
import Anthropic from '@claude-ai/sdk';

const client = new Anthropic();

async function main() {
  const message = await client.messages.create({
    model: 'claude-haiku-4-5-20251001', // Use Haiku for dev — 20x cheaper than Opus
    max_tokens: 512,
    messages: [{ role: 'user', content: 'Summarize this in one sentence: ...' }],
  });

  console.log(message.content[0].);
  .();
}

();