The K2 migration window is closing faster than the model names suggest
The original K2 API series is already retired, while K2.5 and Moonshot V1 access changes are now tied to the K3 rollout.
Audit hard-coded model IDs now. The original K2 preview and thinking IDs are retired, and the current model list points new development toward K3 or K2.7 Code.
Already retired
The Kimi API documentation marks the original K2 series as retired on May 25, 2026. The kimi-latest alias was retired on January 28, 2026, and kimi-thinking-preview was retired in November 2025.
The next deadline
The current model list says K2.5 and Moonshot V1 stopped opening to newly registered users after K3 launched, with a platform-wide retirement date of August 31. Existing integrations should verify their account-specific availability and migrate before that date.
Migration checklist
A clean migration should include more than changing the model string.
- Inventory every hard-coded model ID and fallback
- Retest tool calls and structured output behavior
- Recalculate token budgets for the new context and reasoning settings
- Start new evaluation sessions to avoid stale context-cache comparisons
- Keep a rollback model until production acceptance tests pass