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TutorialMarch 22, 2026·7 min read

Automate Boilerplate Code Generation with a Single API Call

AC

Alex Chen

Developer Advocate

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The Boilerplate Problem

Every project starts with the same tedious setup: CRUD endpoints, validation schemas, type definitions, test scaffolding. A code generation API can produce all of this in seconds, letting you focus on the logic that makes your app unique.

Getting Started

const API_URL = "https://instantapis.net/api/v1/generate";
const API_KEY = "your_api_key_here";

async function generateCode(prompt, language = "typescript") {
  const response = await fetch(API_URL, {
    method: "POST",
    headers: {
      "Authorization": `Bearer ${API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      task: "code",
      input: prompt,
      options: { language },
    }),
  });
  return response.json();
}

Example 1: Generate a REST API Client

const result = await generateCode(`
  Create a TypeScript API client class for a user management API with these endpoints:
  - GET /users - list all users (paginated)
  - GET /users/:id - get user by ID
  - POST /users - create user (name, email, role)
  - PUT /users/:id - update user
  - DELETE /users/:id - delete user

  Include error handling, TypeScript types, and use fetch.
`, "typescript");

console.log(result.data);
// Outputs a complete, typed API client class

Example 2: Generate Validation Schemas

const result = await generateCode(`
  Create Zod validation schemas for:
  - User: name (string, 2-50 chars), email (valid email),
    age (number, 18-120), role (enum: admin, user, moderator)
  - CreateUserInput: same as User but without id
  - UpdateUserInput: all fields optional

  Export all schemas and inferred TypeScript types.
`, "typescript");

Example 3: Generate Test Cases

import requests

API_URL = "https://instantapis.net/api/v1/generate"
API_KEY = "your_api_key_here"

def generate_tests(code, framework="pytest"):
    response = requests.post(API_URL, json={
        "task": "code",
        "input": f"Write comprehensive {framework} tests for this code:\n\n{code}",
        "options": {"language": "python"},
    }, headers={
        "Authorization": f"Bearer {API_KEY}",
        "Content-Type": "application/json",
    })
    return response.json()

# Generate tests for your function
my_function = """
def calculate_discount(price, quantity, customer_type):
    if customer_type == "premium":
        discount = 0.20
    elif quantity > 100:
        discount = 0.15
    elif quantity > 10:
        discount = 0.10
    else:
        discount = 0
    return price * quantity * (1 - discount)
"""

tests = generate_tests(my_function)
print(tests["data"])
# Outputs pytest tests covering all branches and edge cases

Example 4: Generate Database Models

const result = await generateCode(`
  Create Prisma schema models for an e-commerce app:
  - User (id, email, name, orders)
  - Product (id, name, price, stock, category)
  - Order (id, user, items, total, status, timestamps)
  - OrderItem (id, order, product, quantity, price)

  Include proper relations, indexes, and enums for status.
`, "prisma");

Building a Code Generation CLI

import requests
import sys

API_URL = "https://instantapis.net/api/v1/generate"
API_KEY = "your_api_key_here"

def generate(prompt, language, output_file=None):
    response = requests.post(API_URL, json={
        "task": "code",
        "input": prompt,
        "options": {"language": language},
    }, headers={
        "Authorization": f"Bearer {API_KEY}",
        "Content-Type": "application/json",
    })

    data = response.json()
    if data.get("success"):
        code = data["data"]
        if output_file:
            with open(output_file, "w") as f:
                f.write(code)
            print(f"Written to {output_file}")
        else:
            print(code)
    else:
        print(f"Error: {data.get('error')}")

# Usage: python codegen.py "Create a JWT auth middleware" typescript auth.ts
if __name__ == "__main__":
    prompt = sys.argv[1]
    language = sys.argv[2] if len(sys.argv) > 2 else "python"
    output = sys.argv[3] if len(sys.argv) > 3 else None
    generate(prompt, language, output)

What Can You Generate?

  • API routes and handlers — Express, FastAPI, Django
  • Database models — Prisma, SQLAlchemy, TypeORM
  • React components — with TypeScript props and state
  • Utility functions — date formatting, string manipulation, validation
  • Test suites — Jest, pytest, with edge case coverage
  • Config files — Docker, CI/CD, ESLint, Webpack

Cost Per Generation

Each code generation call costs $0.50. Compare that to the 15-30 minutes of developer time (at $75-150/hour) it takes to write boilerplate manually. That's $18-75 saved per generation.

Start generating code — 10 free credits, no setup required.

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