Trust model

Methodology

Official vendor pages are canonical. Automation finds possible changes; a human decides what becomes public.

Official sources first

Pricing, limits, models, plans, and availability are recorded only when an official vendor source supports them. Third-party pages can help discover a change, but they are never canonical evidence. If the vendor does not publish a fact clearly, TraceCheck marks it unknown instead of estimating it.

Detection is not verification

Source adapters periodically fetch allowlisted official URLs, extract the smallest relevant facts, normalize superficial formatting, and compare them with the last approved state. A material difference creates a private pending-review candidate. It does not appear on this site or in RSS.

Human review

A reviewer opens the official source, confirms the material change, updates the current product record, records before and after values, and adds the exact verification time. Only records with status: verified are built into public pages.

Failure behavior

A timeout, unsupported content type, oversized response, non-allowlisted host, or empty extraction is treated as a monitoring failure. Existing public facts remain unchanged and no candidate is published.

Audit trail

Canonical facts and verified changes are structured JSON in Git. Every change URL includes its source URL, fetch time, verification time, and content hash. The product page always shows the latest verification timestamp.