LLM providers are retiring models faster than you can migrate

On May 15, 2026, xAI retired 8 Grok API models. The notice period was 9 days. If you had grok-2, grok-3, or grok-4-fast pinned in production, here's the part that actually bites: the retired slugs don't hard-error. They silently redirect to grok-4.3 - reasoning models drop to low effort, non-reasoning to none - and you get billed at grok-4.3 pricing ($1.25 / $2.50 per 1M tokens). xAI's original retirement email said the requests would "no longer work"; a later docs update