Simon Willison’s Weblog

4th January 2026

It genuinely feels to me like GPT-5.2 and Opus 4.5 in November represent an inflection point - one of those moments where the models get incrementally better in a way that tips across an invisible capability line where suddenly a whole bunch of much harder coding problems open up.

Posted 4th January 2026 at 11:21 pm

Recent articles

One-shotting a Raccoon Heist game using Claude Fable 5 - 5th August 2026
New release of LLM adds support for reasoning traces, OpenAI Responses, server-side tools, and smarter logging - 4th August 2026
Stateless MCP has recaptured my interest (and inspired mcp-explorer and datasette-mcp) - 31st July 2026

This is a note by Simon Willison, posted on 4th January 2026.

ai 2,171 openai 443 generative-ai 1,922 llms 1,889 ai-assisted-programming 401 anthropic 324 claude 299 claude-4 14 gpt-5 31 november-2025-inflection 15 gpt 130

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