Every number is a live, publicly accessible API quote at collection time — the Vast.ai marketplace (real on-demand asks, verified rentable machines, normalized to $/GPU/hr) and the RunPod public price API (Secure + Community cloud). The CS Index is the median of available headline quotes (Vast median ask, RunPod secure, RunPod community). No hand-entered prices, no estimates, no synthetic backfill. Snapshots every 6 hours via GitHub Actions; the full history is free, forever (inception 2026-08-16). Raw data: latest.json · history.json.