Release: llm-anthropic 0.29
Simon Willison’s Weblog
Subscribe
22nd September 2026
Release
llm-anthropic 0.29 — LLM access to models by Anthropic, including the Claude series
Adds support for Claude Opus 5.5:
llm -m claude-opus-5.5 "prompt goes here"
Recent articles
Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price war - 22nd September 2026
Jev introduces a new shape of LLM - System One, aka Decision Models - 21st September 2026
Generating running routes with GPT-6 Astra and ChatGPT Work - 12th September 2026
This is a beat by Simon Willison, posted on 22nd September 2026.
llm 635
anthropic 340
Monthly briefing
Sponsor me for $10/month and get a curated email digest of the month's most important LLM developments.
Pay me to send you less!
Sponsor & subscribe
Disclosures
Colophon
©
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026