Listing Lab: private local-AI copy for independent sellers

Description and use

Listing Lab is a local AI copywriter for independent Etsy, eBay, and Facebook Marketplace sellers, running entirely in the browser without server or API calls.

Problem

Independent Etsy, eBay, and Facebook Marketplace sellers need stronger product copy but cannot justify another subscription or uploading product data to an opaque service.

Outcome

Listing Lab provides a lightweight, privacy-preserving local AI copywriter that eliminates per-generation costs and keeps product data on the seller’s device.

Workflow

• Collect product facts, buyer, price, marketplace, and tone via UI.
• When Generate is clicked, lazily load a quantized ONNX build of SmolLM2-360M-Instruct via Transformers.js.
• Chrome uses WebGPU if available, otherwise falls back to WASM on CPU.
• Model files are cached by the browser after the first download.
• Seller reviews and copies the result; no prompt API or database is used.

Evidence

Listing Lab is a private marketplace copywriter for independent Etsy, eBay, and Facebook Marketplace sellers.

Source

The implementation keeps inference entirely on the client: there is no prompt API, server-side generation endpoint, account system, or prompt database.

Source

The app is a responsive React experience with a visible first-run model download, browser caching, WebGPU acceleration, CPU/WASM fallback, and a plain-language privacy model.

Source