AI & Cloud Infrastructure
November 9, 2026Foundry retires Haiku 4.5 and the o-series: your 10-day plan
Between 15 and 30 November 2026 Microsoft Foundry retires codex-mini, Claude Haiku 4.5, seven o-series models, Llama 4 Maverick and Claude Opus and Sonnet 4.5, and the named o-series replacement rejects tool calls on Chat Completions unless reasoning is switched off. Here is the inventory loop, the cost math from Azure's own price list showing the auto-upgrade roughly doubles an o3 or o4-mini bill, the Haiku 5.5 parameter changes, and a ten-day plan with the EU Data Zone consequences.
Microsoft Foundry
Azure OpenAI
Model retirement
o3
o4-mini
GPT-5.6
GPT-6.1
Claude Haiku 4.5
Claude Haiku 5.5
Responses API
Cost optimisation
Data Zone EU
By Falak Mahmood