# Claude defaults to Sonnet 5.5

> Agno's Claude() moves off the retiring Sonnet 4.5 to a newer default model, and drops temperature, top_p and top_k with a warning on Claude models that reject them.

- Published: 2026-10-21
- Author: Kaustubh Shukla
- Categories: Changelog
- Canonical: https://www.agno.com/blog/claude-defaults-to-sonnet-5-5
- Markdown: https://www.agno.com/blog/claude-defaults-to-sonnet-5-5.md

Agno's `Claude()` now builds requests for `claude-sonnet-5-5` when you leave out `id`. Earlier releases defaulted to `claude-sonnet-4-5-20250929`, which Anthropic deprecated and retires on 30 November 2026, and every `Claude()` without an `id` would have failed from that day.

Sonnet 5.5 answers any request carrying `temperature`, `top_p` or `top_k` with a 400, so Agno now strips them on Sonnet 5.5, Opus 4.7 and any Claude ID it doesn't recognise, and logs a warning.

On those same models, Harsh Sinha's companion fix sends `thinking={"type": "enabled", "budget_tokens": 1024}` as `{'type': 'adaptive', 'display': 'summarized'}`, with a warning that points you to `output_config={'effort': ...}`.

See the [cookbook](https://github.com/agno-agi/agno/blob/main/cookbook/90_models/anthropic/adaptive_thinking.py), and learn more about [Claude models](https://docs.agno.com/models/providers/native/anthropic/overview) in the documentation.