UPDATED JULY 28 — SANCTIONS CHANGE THE RISK CALCULATION
● Performance comparison: Unchanged — K3 SWE Marathon #1, Opus 5 ARC-AGI-3 30.2%
● Price comparison: Unchanged — K3 $3/M input, Opus 5 $5/M input
● NEW — Moonshot API risk: Entity List designation threatened — US enterprises may need license
● NEW — Self-hosted K3 risk: Lower — Modified MIT weights already released cannot be recalled
● Claude Opus 5 risk: Zero regulatory risk — US company, White House framework signatory, FLI C+
● Recommendation change: Freeze new Moonshot API commitments; existing self-hosted weights lower risk
If you are evaluating K3 vs Opus 5 today: The performance and price case for K3 is unchanged. The regulatory risk has materially increased for the Moonshot-hosted API. If you need zero regulatory risk, Opus 5 is the answer. If you are comfortable with self-hosted K3 on Western infrastructure using already-downloaded Modified MIT weights, the risk is lower — but get a legal opinion before expanding production commitments.
Last updated July 28, 2026. Related: Full sanctions analysis → · Claude Opus 5 full review →