Hi HN, author here.
I built CommerceTXT because I got tired of the fragility of extracting pricing and inventory data from HTML. AI agents currently waste ~8k tokens just to parse a product page, only to hallucinate the price or miss the fact that it's "Out of Stock".
CommerceTXT is a strict, read-only text protocol (CC0 Public Domain) designed to give agents deterministic ground truth. Think of it as `robots.txt` + `llms.txt` but structured specifically for transactions.
Key technical decisions v1.0:
1. *Fractal Architecture:* Root -> Category -> Product files. Agents only fetch what they need (saves bandwidth/tokens).
2. *Strictly Read-Only:* v1.0 intentionally excludes transactions/actions to avoid security nightmares. It's purely context.
3. *Token Efficiency:* A typical product definition is ~380 tokens vs ~8,500 for the HTML equivalent.
4. *Anti-Hallucination:* Includes directives like @INVENTORY with timestamps and @REVIEWS with verification sources.
The spec is live and open. I'd love your feedback on the directive structure and especially on the "Trust & Verification" concepts we're exploring.
Spec: https://github.com/commercetxt/commercetxt
Website: https://commercetxt.org
All these files should be registered with IANA and put under the .well-known namespace.
https://en.wikipedia.org/wiki/Well-known_URI