Honestly, I don't prefer the coding output of Claude models. This includes Opus 4.5. Frankly, I have trouble understanding why people think it's so superior. I use gpt-5.2-codex on High reasoning almost exclusively, and I much prefer the work it does. Not sure what I'm seeing differently here.

I was reading through the docs for GPT 5.2 and stumbled across this *extremely* interesting little tiny snippet in there that I somehow had always missed before (was it in 5.1?). Turns out you can force GPT 5.2 to respond to you with a DSL! Am I the last one to learn this?

Last night I was at a local emerging tech meetup, and the presenter was showing how he used Claude Code to do his data analysis workflow. That's cool and all, but wasn't really news to me. What was interesting was the questions that people asked. 1/x

I think too many people focus on whether or not a model can "one shot" a project. I understand the excitement of the idea, like "what could I get with just a single wish", but I believe approaching AI-driven development this way misses a ton of extremely useful capabilities. 1/x

"enshittfying our potable water" truly is the enshittification of "enshittification"

This tracks.

I build a lot of stuff, and I want people to see it, but I just never have the instinct to post about it anywhere. I don't really know why. I'm going to start doing that, especially now that there's an AI community here. I just need to actually make a point of sharing what I build.

OpenAI aren't talking about it yet, but it turns out they've adopted Anthropic's brilliant "skills" mechanism in a big way Skills are now live in both ChatGPT and their Codex CLI tool, I wrote up some detailed notes on how they work so far here: simonwillison.net/2025/Dec/12/...

Possibly medium-temperature post: I'm a child of the 80's. There are certain films that were "core" to that identity. One of those was Flashdance, which I had never actually seen. We've all seen clips. We've all seen "Maniac". So I finally watched it. It's bad. It's terrible. Not a good film.

A series of Opus 4 self-portraits, from a conversation with itself