Show DEV: I Built an AI Rap Generator that Creates Full Songs (Not Just Lyrics)

chou cairne — Thu, 13 Nov 2025 06:45:08 +0000

For the past few months, I've been working as a solo developer on a project I'm incredibly passionate about, and I'm finally ready (and nervous!) to share it.

The project is RapGenerator AI: https://www.rapgeneratorai.com

The Problem
I was getting frustrated with the "AI Rap" tools out there. Almost all of them are just "Lyric Generators." They give you a block of text, and that's it.

As a user, I felt cheated. I wanted the full experience. I wanted to hear the song.

The Solution: A Full Song Generator
So, I decided to build a tool that handles the entire process. You give it a simple text prompt (like "a rap song about my cat"), and in about 60 seconds, it generates a complete, original rap song—including:

AI-generated Lyrics (with hooks and verses)

AI-generated Vocals (with a realistic flow)

A high-quality Beat

Final Mixing

The Tech Stack (The Fun Part)
For my fellow devs, here's a look under the hood. The project is built on a Next.js 14 (App Router) stack.

Frontend: Next.js, Tailwind CSS, Radix UI

Backend: Next.js API Routes

Auth & Payments: My SaaS boilerplate already had Better Auth & Creem integrated.

Database: PostgreSQL with Drizzle ORM

The "AI Magic" is a 3-part chain:

Lyrics: I use a large language model (LLM like GPT-4o or Claude 3) with a very specific, multi-step prompt. This forces the AI to output a consistent structure ([Hook], [Verse 1], [Hook]) and maintain rhymes.

Vocals: This was the hardest part. I'm using a specialized Singing Voice Synthesis (SVS) API (like ElevenLabs). This isn't just a simple TTS. It takes the text, a voice ID, and parameters for rhythm and emotion to generate a surprisingly good acapella (vocal-only) track.

Mixing: The backend then takes the generated acapella, grabs one of the royalty-free beats from its library (matching the BPM!), and uses FFMPEG on the server to mix them into the final MP3 that the user hears.

The Ask
This is still an MVP, and I'd be incredibly grateful for this community's feedback. There's a free plan, so you can try it out right now without signing up.

Let me know what you think!

After 10 Years in China's SaaS Scene, I'm Betting My Future on a $55 Screenshot

chou cairne — Fri, 03 Oct 2025 11:58:42 +0000

For the last 10 years, I’ve been working in the SaaS industry in China, mostly on the operations and growth side. But the itch to build my own thing, from scratch, for a global audience, finally became too strong to ignore.

This is the story of how a single screenshot validated my idea and led to a unique product approach that I've just launched on my new website.

It all started when I saw this:

This is a pet business owner paying ~$55 for a simple, AI-generated video ad. It sent me down a rabbit hole of research, and I confirmed that while there are many generalist AI video tools, none of them are built for the specific needs of a pet business owner. They are too complex, too generic, and too time-consuming.

My Solution: A Niche-Focused, "Done-for-You" Approach
Instead of building another blank-canvas AI tool, I decided to focus on what the user actually wants: a great result, fast. This led to two key product decisions for my solution, petadgen.com:

1. Smart, Data-Driven Templates: I realized that starting from a blank page is intimidating. So, instead of random templates, I analyzed major e-commerce platforms to find the 6 hottest-selling pet product categories. I then designed a pre-built video template for each one. The workflow is simple: you upload your product photo and can immediately choose a proven template. The AI already knows the right vibe for a smart feeder ad versus a chew toy ad. For users who want more control, you can always skip the templates and write your own custom prompts. It's the best of both worlds: simplicity for beginners, flexibility for pros.

2. High-Quality Models for Product Integrity: A major issue with many AI video tools is that they warp or distort the original product image. This is a deal-breaker for a business. To solve this, I'm using a combination of powerful models, including Nano Banana and Veo3 Fast. This ensures two things: your product's integrity is maintained, and the final video quality is sharp, vibrant, and professional.

I believe this combination of data-driven templates and high-quality AI models is the key to solving the problem I discovered.

I’ve put it all together on the new landing page I've launched. You can see the full demo and real video examples here: https://petadgen.com

My Ask: Take a Look and Share Your Thoughts
My #1 goal right now is to get feedback on this approach from real potential users and fellow builders.

I would be incredibly grateful if you could take a moment to visit petadgen.com, see the demo, and let me know what you think.

There's a short Tally form on the site to join the early-access waiting list, which is the main channel where I'm collecting initial feedback. Your insights at this stage are gold and will directly shape the product's future. As a thank you, everyone on the waiting list will get priority access and a special launch offer.

My Questions for the broader IH Community:

Does this approach of using templates based on best-selling product types make sense to you?

What's the best way to get this landing page in front of pet business owners (especially dropshippers or e-commerce stores)?

For the tech-savvy builders here, any thoughts or experiences with the models I'm using?

Thanks for being a part of my "build in public" journey.

Forem: chou cairne

Show DEV: I Built an AI Rap Generator that Creates Full Songs (Not Just Lyrics)

After 10 Years in China's SaaS Scene, I'm Betting My Future on a $55 Screenshot