Anthropic change
Claude Codeclaude-sonnet-4-5-20250929 retires November 30, 2026
claude-sonnet-4-5-20250929 retires on the Claude API on November 30, 2026, and Anthropic's model deprecations page names claude-sonnet-5-5 as its replacement. Requests to a model past its retirement date fail, as requests to the already retired models in the table below fail now.
Next step in your repo: run npx -y viberaven@1.7.8 changes. It lists claude-sonnet-4-5-20250929 and eight of the retired IDs below, wherever your code or env templates name them, as anthropic-claude-model-retirements, with the file and line: on a fixture repo on 2026-11-03 it printed "lib/claude.ts:7: uses claude-sonnet-4-5-20250929 (retires 2026-11-30)". Its checks are scoped to Vercel + Supabase apps and read repository files only: advice, not a gate, and not a live database test.
OpenAI is removing models on three dates as well. See the OpenAI model shutdown dates and replacements.
Why it matters
Who the date applies to
Anthropic deprecated Claude Sonnet 4.5 on September 30, 2026. Its policy gives at least 60 days' notice before a publicly released model retires, and the dates apply to the platforms Anthropic operates: the Claude API, Claude Platform on AWS, Claude Models on Google Cloud (Anthropic managed) and Microsoft Foundry. Amazon Bedrock and Claude Models on Google Cloud (Google managed) set their own schedules. Checked against Anthropic's model deprecations page on 2026-11-03.
Find the model IDs in your code
Search the code, env templates and config for the dated IDs in the table. Model names often sit in an environment variable such as ANTHROPIC_MODEL, so also check the values set in your hosting provider, which the repository does not show.
grep -rnE --exclude-dir=node_modules "claude-(sonnet-4-5-20250929|sonnet-4-20250514|opus-4-20250514|opus-4-1-20250805|3-[57]-sonnet|3-5-haiku|3-haiku|3-opus|3-sonnet|2\.[01]|1\.[0-3]|instant)" .Switch to claude-sonnet-5-5 and remove sampling parameters
Change the model string, then run each AI feature once and compare the output, token use and cost. Anthropic's deprecations page also lists temperature, top_p and top_k as removed in API version 2026-10-21, where they return a 400 error; on earlier API versions they return the 400 when set to a non-default value on Claude 4.7 and later models. Code that sends temperature to claude-sonnet-4-5-20250929 can start failing when only the model ID changes, so remove those parameters in the same change and guide the output with the prompt instead.
Amazon Bedrock, Google Cloud and gateways
Bedrock model IDs such as anthropic.claude-sonnet-4-5-20250929-v1:0 and IDs sent through a gateway such as OpenRouter follow that platform's schedule, not the dates above. Check the platform's own model lifecycle page before you change them.
Checklist
Before November 30, 2026
- 01Search the code, env templates and your hosting provider's environment variables for each model ID in the table.
- 02Replace claude-sonnet-4-5-20250929 with claude-sonnet-5-5, and each retired ID with its recommended replacement.
- 03Remove temperature, top_p and top_k from the same requests.
- 04Run each AI feature once: compare the output, the token use and the cost per request.
- 05Deploy before November 30, then watch the logs for errors that name a model.
Retirement table
Claude model IDs that are retired or retiring
Copied from Anthropic's model deprecations page on 2026-11-03. A date in the past means requests to that model already fail on Anthropic-operated platforms.
Model ID, retirement date and recommended replacement
| Model ID | State | Retirement date | Recommended replacement |
|---|---|---|---|
| claude-sonnet-4-5-20250929 | Deprecated | November 30, 2026 | claude-sonnet-5-5 |
| claude-opus-4-1-20250805 | Retired | August 5, 2026 | claude-opus-4-8 |
| claude-sonnet-4-20250514 | Retired | June 15, 2026 | claude-sonnet-5-5 |
| claude-opus-4-20250514 | Retired | June 15, 2026 | claude-opus-4-8 |
| claude-3-haiku-20240307 | Retired | April 20, 2026 | claude-haiku-4-5-20251001 |
| claude-3-7-sonnet-20250219 | Retired | February 19, 2026 | claude-sonnet-5-5 |
| claude-3-5-haiku-20241022 | Retired | February 19, 2026 | claude-haiku-4-5-20251001 |
| claude-3-opus-20240229 | Retired | January 5, 2026 | claude-opus-4-8 |
| claude-3-5-sonnet-20240620 | Retired | October 28, 2025 | claude-sonnet-5-5 |
| claude-3-5-sonnet-20241022 | Retired | October 28, 2025 | claude-sonnet-5-5 |
| claude-3-sonnet-20240229 | Retired | July 21, 2025 | claude-sonnet-5-5 |
| claude-2.0, claude-2.1 | Retired | July 21, 2025 | claude-opus-4-8 |
| claude-1.0 to claude-1.3, claude-instant-1.0 to claude-instant-1.2 | Retired | November 6, 2024 | claude-haiku-4-5-20251001 |
Related
Related guides
Sources
Official docs behind this checklist
Browse all launch guides · Read resources · How to make and check your next change
FAQ
FAQ for builders before launch
What does a request to a retired Claude model return?
Anthropic's page says requests to models past the retirement date fail. It does not document the error body, so we do not quote one here.
Does Anthropic email me before a retirement?
Anthropic says it notifies customers with active deployments of a model with an upcoming retirement, at least 60 days before, by email and in its documentation.