Free, transparent AI listings — built by one indie dev over a weekend

Why this exists

I kept hitting the same wall when looking for an AI listing tool: every option was either $39+/month or a free trial that emailed me within 30 minutes. And none of them showed me the actual prompt being sent to the model on my behalf — was it injecting affiliate links? Biased toward an upsell tier? Who knows.

So I built ListForge as the tool I wished existed: free, rate-limited per IP rather than gated behind a signup wall, and completely transparent about what it does. To make that transparency real instead of marketing language, I open-sourced the entire production prompt file the day it launched.

What makes it different

• Open-source prompts

  The exact production prompt file is public on GitHub under MIT license. Read it. Fork it. Submit a PR.

• 3 streamed variants

  Conservative (spec-driven), Balanced (mainstream), Creative (pain-point hook). Each one is a structurally different angle — not a paraphrase.

• Locale-aware

  Pick “United Kingdom” → British English. Pick “Germany” → entire listing in German. Currently handles US, UK, AU, CA, DE, FR, JP.

• Free, no account

  Per-IP hourly rate limit. Hit the cap, wait an hour. No card, no email, no “upgrade for the real prompts” gotcha.

The build

ListForge is a Next.js 16 app deployed on Vercel. It uses DeepSeek as the LLM backend (roughly 1/30 the output-token cost of GPT-4 at comparable listing quality — which is what makes the free tier sustainable). The Vercel AI SDK's streamObject function powers the parallel-streaming UI: three variants stream back simultaneously, multiplexed over a single NDJSON response. Rate limiting runs on Upstash Redis with a sliding-window token bucket. Total codebase: ~3,500 LOC.

What this isn't

• Not a Helium 10 / Jungle Scout replacement. No keyword research, PPC analytics, or competitor tracking.
• Not financial / legal advice.If you sell in a regulated category (supplements, electronics, kids' products, etc.), have a human review the output before you publish.
• Not a moat. The prompts are open. If you can run this better than I do, please fork the code and out-execute me.

Roadmap

Honest roadmap: there isn't a hard one. ListForge is run break-even by a solo dev. Things being considered, in roughly decreasing likelihood:

• More target locales (Spanish, Italian, Korean)
• CSV bulk upload (likely behind a small paid tier — the free tier stays free)
• Comparison view (paste your existing listing → diff against generated alternatives)
• Optional GPT-4 / Claude backend for users who want it

If you have a feature you actively need, open an issue on the prompts repo or email me directly.