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21 posts about Model Deprecation from Simon Carter.
gpt-5.4-cyber is deprecated with a hard removal on 1 October 2026. The replacement is gpt-5.6-cyber, but migration requires Daybreak Red approval.
OpenAI has set 14 October 2026 as the hard retirement date for GPT-5.5 in ChatGPT, ChatGPT Work, and Codex. The API is unaffected.
Google deprecates gemini-omni-flash-preview on 30 September 2026. Teams must migrate to the GA gemini-omni-1.1-flash endpoint before that date.
Google retires gemini-robotics-er-1.6-preview on 31 August 2026. The replacement, gemini-robotics-er-2-preview, adds multi-robot coordination and agentic code execution.
From 31 August 2026, GPT-5.4 and GPT-5.4 mini no longer work in Codex under ChatGPT sign-in. Here is what to do.
Anthropic's Claude 3 Haiku on Vertex AI reached end-of-life on 23 August 2026. Any app still calling it will now receive errors.
On 26 August 2026, OpenAI removes o3 from ChatGPT's model picker and permanently shuts down the Assistants API. Here's what breaks and what to do.
The xai/grok-4.1-fast-reasoning and xai/grok-4.1-fast-non-reasoning model IDs stop working on 20 August 2026. Here's how to migrate.
Three Imagen 4 API endpoints shut down permanently on 17 August 2026. Here's what broke, why, and how to migrate to gemini-3.1-flash-image.
Google has reversed its 4 August 2026 deadline to remove Gemini 3.5 Flash from the global-region endpoint. No new date has been set.
OpenAI has set 26 August 2026 as the hard retirement date for o3 in ChatGPT, following a 90-day sunset period announced on 28 May 2026.
The claude-opus-4-1-20250805 model ID retired on 5 August 2026. API calls to it now return a hard 404. Here is what to do.
From 4 August 2026, gemini-3.5-flash is no longer available in the global-region endpoint of the Gemini Enterprise app. Here's what to check.
OpenAI is retiring GPT-5.4 and GPT-5.4 mini from Codex for ChatGPT-authenticated users on 31 August 2026. Here's what to do before the deadline.
The claude-opus-4-1-20250805 model ID stops working on 5 August 2026. Here's what to change and why Opus 4.8 is the right target.
Anthropic has deprecated claude-opus-4-1-20250805 with a retirement date of August 5, 2026. Opus 4.8 is the recommended replacement.
As of June 15, 2026, claude-sonnet-4-20250514 and claude-opus-4-20250514 return errors. Migrate to Sonnet 4.6 and Opus 4.8.
Anthropic has formally deprecated claude-mythos-preview with a June 30 2026 retirement date, directing developers to migrate to claude-mythos-5 — which is currently suspended.
GPT-4.5 leaves ChatGPT on June 27, 2026 and o3 on August 26. No API changes. Here's what it means for you.
Google has pushed the Vertex AI retirement date for Gemini 2.5 Pro, Flash, and Flash-Lite to October 16, 2026, giving developers more time to migrate to Gemini 3.x.
As of June 12, 2026, GPT-5.2 Instant, Thinking, and Pro are retired from ChatGPT, with all conversations auto-migrated to GPT-5.5 equivalents.