Three layers.
Discovery. Canonical graph. Transaction. Each layer has its own domain and its own job.
worldpaperindex.com — this site
Google-indexable, free, editorial-first. Every grade, mill, and brand has a canonical URL with rich structured data (schema.org/Product). News, guides, hub articles cross-link to them.
You're reading it right now.
wpi-canonical.xdvu.com — the API
A Postgres + pgvector graph with immutable WPI-* IDs. Every grade, mill, brand, certification, alias, and substitutability edge lives here. Exposed as a JSON REST API for programmatic use — free, rate-limited.
See the API page for endpoints.
b2bpaper.com — the marketplace
A live B2B surplus marketplace for paper mills: buyers post requirements, mills post surplus lots, the platform matches them, and deals close with a container-optimised logistics layer. 350+ verified buyers across 40+ countries.
Grade pages on this site show live availability from B2BPaper (count, price range, country mix) and link buyers straight into the flow.
The flywheel
Google sends intent-laden queries to this site. We show the grade and the live availability. You click through to B2BPaper to transact. Closed-deal aggregates (anonymised, k-anonymity ≥ 3) flow back as market-price panels. Each loop makes the next loop more useful.