1. Source policy
Model prices must come from a provider-owned pricing page, API document, or formal release note. News articles, social posts, snippets, and third-party price databases are discovery sources, not final evidence.
2. Price normalization
Input, cached input, and output prices are normalized to USD per one million tokens. A missing rate remains unavailable rather than being converted to zero.
3. Calculation
per request = input cost + cached input cost + output cost monthly = per request × requests/day × 30
4. Exclusions
Taxes, account tiers, minimum commitments, tool calls, storage, fine-tuning, batch rules, data transfer, and regional terms are excluded unless the page explicitly models them.
5. Verification
Every verified model records an effective date and a last-checked date. A model page must be updated when its underlying price changes; the page date must not be refreshed merely to look current.
6. Corrections
When a source changes or an error is found, update the data file, retain the new official source, rebuild the site, and record the change in version control.