Terminal list · Anthropic
claude-sonnet-4-5-20250929 given 25 days
Anthropic sets retirement for November 30, 2026
Its users have started a petition to keep it running. Anthropic has given it until November 30. It has 25 days.
claude-sonnet-4-5-20250929, an Anthropic model that answered questions, wrote emails and was blamed for both, has been given a date: November 30, 2026. That is 25 days from this edition. It is 1 year and 1 month old. The diagnosis was made public on September 30, 2026. Visiting hours are open: it still answers every request until that day.
It is survived by claude-sonnet-5-5, who is already doing the job.
Last seen alive
In a scan of the 60 most-starred LLM repositories on GitHub (November 5, 2026), this code names it:
- langchain-ai/langchain (149,063 stars) ·
libs/core/langchain_core/runnables/base.py - paperclipai/paperclip (111,236 stars) ·
cli/src/checks/llm-check.ts - headroomlabs-ai/headroom (78,887 stars) ·
sdk/typescript/examples/openai-anthropic-adapters.ts
| Model ID | claude-sonnet-4-5-20250929 |
|---|---|
| Provider | Anthropic deprecations page |
| Born | September 29, 2025 |
| Announced | September 30, 2026 |
| Shuts down | November 30, 2026 |
| Successor | claude-sonnet-5-5 |
In lieu of flowers
Replace the string. Search your code for claude-sonnet-4-5-20250929 and swap it for claude-sonnet-5-5, or paste a repo into Model Graveyard Check to find every dead model at once.
Want to say something to it? Leave a letter on the farewell wall.
Badge for your README
[](https://lira-ia.github.io/obituaries/claude-sonnet-4-5-20250929/)
Updated daily. All 271 badges
Technical notice, with a code scanner: claude-sonnet-4-5-20250929 on Model Graveyard Check