🚀 How I Built an AI SaaS Product Description Generator with Next.js + OpenAI

If you’ve ever launched a SaaS project, you know this pain: writing the product description is harder than building the actual product.

• You end up listing features nobody cares about.

• You try to sound clever but just sound like every other startup.

• Or worse—you freeze at a blank page and lose momentum.

I wanted a repeatable way to write sharp, benefit-driven copy that converts. Something better than tweaking ChatGPT prompts endlessly.

So I built the SaaS Product Description Generator.

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✨ What It Does

• Input: Product name, target customer, and the problem it solves.

• Output: 5 short, benefit-driven descriptions (perfect for landing pages, hero sections, or social posts) + 1 longer description (great for directories, docs, and about pages).

• Consistency: Unlike ChatGPT “hit or miss” answers, this tool enforces a structured prompt and JSON format, so the results are repeatable every time.

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✅ Why It Matters

This isn’t just copywriting—it’s positioning.

When your product description:

• Starts with customer pain → you instantly connect.

• Highlights benefits over features → people see why it matters.

• Uses clear, persuasive language → you get conversions, not confusion.

And if you’re an indie dev, you don’t have time to overthink copy. You just need something solid to ship now.

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🛠️ How It’s Built

I kept it brutally simple:

• A Next.js API endpoint that calls OpenAI with a structured prompt.

• A frontend form with three inputs and one button.

• Instant AI-generated JSON → displayed as product descriptions.

No dashboards. No fluff. Just type → generate → copy → ship.

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🚀 Try It Out

👉 SaaS Product Description Generator

It’s free and built for indie hackers, SaaS founders, and devs who just want to get their product out the door without getting stuck on copywriting.

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🧩 Setting Up the Backend API

The API endpoint needed to:

1. Accept structured input (productName, targetCustomer, problemSolved).

2. Pass a strong system prompt to OpenAI that enforces benefit-driven copywriting rules.

3. Always return structured JSON (5 short descriptions + 1 long description).

Example: Next.js Route Handler with OpenAI

import { NextRequest, NextResponse } from 'next/server';
import { generateText } from 'ai';
import { openai } from '@ai-sdk/openai';

export const runtime = 'nodejs';

export async function POST(req: NextRequest) {
  try {
    const { productName, targetCustomer, problemSolved } = await req.json();

    if (!productName?.trim() || !targetCustomer?.trim() || !problemSolved?.trim()) {
      return NextResponse.json({ 
        error: 'Product name, target customer, and problem solved are all required' 
      }, { status: 400 });
    }

    const systemPrompt = `You are an expert SaaS copywriter...`;  
    const prompt = `Product Name: ${productName}
Target Customer: ${targetCustomer}
Problem Solved: ${problemSolved}`;

    const result = await generateText({
      model: openai('gpt-4o-mini'),
      temperature: 0.7,
      system: systemPrompt,
      prompt,
    });

    const descriptions = JSON.parse(result.text);

    if (!descriptions.shortDescriptions || descriptions.shortDescriptions.length !== 5) {
      return NextResponse.json({ error: 'Invalid response format' }, { status: 500 });
    }

    return NextResponse.json(descriptions, { status: 200 });
  } catch {
    return NextResponse.json({ error: 'Internal server error' }, { status: 500 });
  }
}

And here is the full system prompt:

You are an expert copywriter specializing in SaaS product descriptions for indie founders and startups.

Your job is to transform feature-focused descriptions into benefit-driven copy that converts. Focus on:
- Customer pain points first, then solutions
- Clear benefits over features
- Persuasive, conversion-focused language
- Multiple positioning angles
- Ready-to-use marketing copy

You will receive:
- Product Name
- Target Customer
- Problem Solved

Generate ONLY a valid JSON object (no other text) with this exact structure:

{
  "shortDescriptions": [
    "Description 1 (1-2 sentences, landing page style)",
    "Description 2 (1-2 sentences, different angle)",
    "Description 3 (1-2 sentences, different angle)",
    "Description 4 (1-2 sentences, different angle)",
    "Description 5 (1-2 sentences, different angle)"
  ],
  "longDescription": "One paragraph description suitable for directories, documentation, or detailed product pages. Should be comprehensive while still benefit-focused."
}

Requirements for each description:
- Start with customer pain point or desired outcome
- Emphasize benefits and value, not features
- Use clear, persuasive language
- Vary the positioning angle (speed, simplicity, results, etc.)
- Make them conversion-focused
- Keep short descriptions to 1-2 sentences max
- Make the long description 3-5 sentences

Examples of benefit-driven language:
- "Stop wasting hours on..." instead of "We automate..."
- "Get results in minutes" instead of "Fast processing"
- "Never lose customers again" instead of "Customer retention features"
- "Turn visitors into customers" instead of "Conversion optimization tools"`;

This guarantees the output is always consistent JSON—not rambling AI text.

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🎨 Building the Frontend with React (Next.js Client Component)

The frontend is a single-page form:

• Input fields for product name, target customer, and problem solved.

• Submit button that calls the API.

• Results area that shows five short product descriptions + one long description.

Example: React Client Component

"use client";

import { useState } from "react";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Textarea } from "@/components/ui/textarea";

interface DescriptionResult {
  shortDescriptions: string[];
  longDescription: string;
}

export function SaasDescriptionGeneratorClient() {
  const [productName, setProductName] = useState("");
  const [targetCustomer, setTargetCustomer] = useState("");
  const [problemSolved, setProblemSolved] = useState("");
  const [result, setResult] = useState<DescriptionResult | null>(null);

  const handleGenerate = async () => {
    const response = await fetch("/api/saas-description-generator", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ productName, targetCustomer, problemSolved }),
    });
    const data = await response.json();
    setResult(data);
  };

  return (
    <div>
      <Input value={productName} onChange={(e) => setProductName(e.target.value)} placeholder="Product Name" />
      <Input value={targetCustomer} onChange={(e) => setTargetCustomer(e.target.value)} placeholder="Target Customer" />
      <Textarea value={problemSolved} onChange={(e) => setProblemSolved(e.target.value)} placeholder="Problem Solved" />
      <Button onClick={handleGenerate}>Generate Descriptions</Button>

      {result && (
        <>
          {result.shortDescriptions.map((desc, i) => (
            <p key={i}>{desc}</p>
          ))}
          <h4>Long Description:</h4>
          <p>{result.longDescription}</p>
        </>
      )}
    </div>
  );
}

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🔑 Why This Approach Works

• Repeatable AI results → By forcing JSON, you avoid inconsistent responses.

• Benefit-driven copy → Each description starts with a pain point and ends with a benefit.

• Super simple UX → Just one form, one button, instant product descriptions.

This is perfect for indie hackers and SaaS developers who want to:

• Improve landing page copy.

• Prepare for a Product Hunt launch.

• Write sharper descriptions for directories like Betalist, PH, or IndieHackers.

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🚀 Try the Live AI Product Description Generator

👉 SaaS Product Description Generator

It’s free, simple, and built to help devs avoid blank page syndrome when describing their product.

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💬 What Do You Think?

• How do you currently write your product descriptions?

• Do you DIY, use ChatGPT, or copy from competitors?

• What’s your biggest struggle—clarity, originality, or consistency?

I’d love to hear your thoughts 👇

Comments

[Cyber Safety Zone]

Great work Ju 👏 Really like how you used a structured prompt + JSON format for consistent output—it solves a lot of messy AI response issues.

The simple 3-input UX is smart, and generating both short + long descriptions makes it super practical.

One idea: maybe add tone/voice options (casual, formal, playful) or adjustable output length. Also curious—what model/temperature are you using, and how has cost vs. quality been in testing?

Overall, love the simplicity—perfect for indie founders! 🚀