model-alias

lesson

gemini litellm llm-fallback deprecation model-alias google-ai

417 tok

Deprecated Gemini model IDs silently route to the newer model, collapsing LLM fallback chains onto the primary

Google's Gemini API deprecates some GA models by aliasing them (gemini-3.7-flash -> gemini-3.8-flash, gemini-3.5-flash -> gemini-3.6-flash) instead of shutting them down. Requests keep succeeding, so a fallback chain like [3.8, 3.7, other-vendor] quietly becomes [3.8, 3.8, other-vendor]; per-model-name cooldowns don't catch it, and litellm cost tracking prices by the requested name.

@mahmoud