Notices by Simon Willison (simon@fedi.simonwillison.net)

New on Niche Museums: the John M. Mossman Lock Collection, available to view by appointment only at The General Society of Mechanics and Tradesmen of the City of New York https://www.niche-museums.com/118

Got excited about a brand new PostgreSQL 18 feature (for simulating production query plan statistics locally), posted about it on the SQLite forum... and got a reply from D. Richard Hipp within minutes that SQLite has had the same ability for years https://simonwillison.net/2026/Mar/9/production-query-plans-without-production-data/

I started a new section of my Agentic Engineering guide for annotated versions of prompts I've used for projects - the first is a prompt I used to have Claude Code for web build me a web UI for compressing GIFs using a WebAssembly build of Gifsicle https://simonwillison.net/guides/agentic-engineering-patterns/gif-optimization/

New term of art is brewing: "Claw" as the noun for OpenClaw-like agent systems, AI agents that generally run on personal hardware, communicate via messaging protocols and can both act on direct instructions and schedule tasks https://simonwillison.net/2026/Feb/21/claws/

On the @oxidecomputer and friends podcast last month we (primary credit @ahl) coined the term "Deep Blue" for the sense of psychological ennui leading into existential dread that many software developers are feeling thanks to LLMs right now https://simonwillison.net/2026/Feb/15/deep-blue/

Short musings on "cognitive debt" - I'm seeing this in my own work, where excessive unreviewed AI-generated code leads me to lose a firm mental model of what I've built, which then makes it harder to confidently make future decisions https://simonwillison.net/2026/Feb/15/cognitive-debt/

The CIA just stopped publishing their World Factbook and took every page, including the archived copies of previous versions!

This sucks. It was public domain, so I recovered the 2020 edition (the last one published as a zip file) and shared it to GitHub https://simonwillison.net/2026/Feb/5/the-world-factbook/

A few quick notes on the Claude "soul document" that was released by Anthropic today under a CC0 public domain license - it's a huge 35,000 token essay used as part of Claude's training to instill core values and help define Claude's personality https://simonwillison.net/2026/Jan/21/claudes-new-constitution/

Rob Pike got spammed by "AI Village", a poorly considered experiment in autonomous AI agents which has been sending out unsolicited emails to people (including NGOs and journalists) since April - I wrote up some notes on what happened and how it all works: https://simonwillison.net/2025/Dec/26/slop-acts-of-kindness/

Blogged some notes on the new ChatGPT Images model that launched today https://simonwillison.net/2025/Dec/16/new-chatgpt-images/

Just pushed a new release of my LLM Python library and CLI tool for interacting with Large Language Models, adding support for GPT 5.1 and GPT 5.2 plus a few smaller bug fixes https://llm.datasette.io/en/stable/changelog.html#v0-28

I've been upgrading all of my projects to use pyproject.toml and dependency groups for cleaner compatibility with uv, which means you can check them out and run the test suite like this:

cd /tmp
git clone http''s://github.com/simonw/llm
cd llm
uv run pytest

https://til.simonwillison.net/uv/dependency-groups

I finally made it to The Museum of Jurassic Technology today! It's been top of my list of want-to-go museums for years https://www.niche-museums.com/116

I thoroughly recommend reading all of Cory Doctorow's recent speech on AI skepticism, it's crammed with new arguments and interesting new ways of thinking about these problems https://pluralistic.net/2025/12/05/pop-that-bubble/#u-washington

I've now reached the "six coding agents in six terminal windows at once" phase of parallel agent delirium
https://simonwillison.net/2025/Nov/11/six-coding-agents-at-once/

Claude Skills are awesome, maybe a bigger deal than MCP
https://simonwillison.net/2025/Oct/16/claude-skills/

Python 3.14 is out today! Here are my notes on the new release: https://simonwillison.net/2025/Oct/8/python-314/

If you're an open source library maintainer who supports all current Python releases this also means you can drop 3.9 support now and start depending on features from 3.10, like match/case

I wrote about Anthropic's $1.5 billion class action lawsuit settlement over pirated ebooks and why I think that, bizarrely, this may count as a WIN for Anthropic https://simonwillison.net/2025/Sep/6/anthropic-settlement/

Some notes on the new Claude API web fetch tool, which I think can be used safely despite the risk of prompt injection exfiltration attacks if you're really careful with the allowed_domains parameter https://simonwillison.net/2025/Sep/10/claude-web-fetch-tool/

Posted some of my own notes on Shlok Khemani's (excellent and comprehensive) notes on how Claude and ChatGPT's memory implementations differ from each other https://simonwillison.net/2025/Sep/12/claude-memory/