Archive - Simon Willison’s Newsletter

FastRender: a browser built by thousands of parallel agents

In this newsletter:

19 mins ago • Simon Willison

First impressions of Claude Cowork, Anthropic’s general agent

Plus Fly’s new Sprites.dev addresses both developer sandboxes and API sandboxes at the same time

Jan 13 • Simon Willison

LLM predictions for 2026, shared with Oxide and Friends

With promising news for Kākāpō parrot breeding season

Jan 9 • Simon Willison

2025: The year in LLMs

Plus introducing gisthost.github.io

Jan 2 • Simon Willison

December 2025

A new way to extract detailed transcripts from Claude Code

and How Rob Pike got spammed with an AI slop “act of kindness”

Dec 28, 2025 • Simon Willison

OpenAI are quietly adopting skills, now available in ChatGPT and Codex CLI

Plus using coding agents to port Rust to Python and then Python to JavaScript

Dec 17, 2025 • Simon Willison

GPT 5.2 and useful patterns for building HTML tools

Plus a YouTube video, a podcast appearance and more

Dec 12, 2025 • Simon Willison

November 2025

Claude Opus 4.5, and why evaluating new LLMs is increasingly difficult

Plus Nano Banana Pro is the best available image generation model

Nov 25, 2025 • Simon Willison

Trying out Gemini 3 Pro with audio transcription and a new pelican benchmark

Plus what happens if AI labs train for pelicans riding bicycles?

Nov 19, 2025 • Simon Willison

Code research projects with async coding agents like Claude Code and Codex

Plus reverse engineering Codex CLI to get GPT-5-Codex-Mini to draw me a pelican

Nov 11, 2025 • Simon Willison

A new SQL-powered permissions system in Datasette 1.0a20

Plus MCP on the file system and security updates for Datasette 0.65.x

Nov 6, 2025 • Simon Willison

New prompt injection papers: Agents Rule of Two and The Attacker Moves Second

Plus hacking the WiFi-enabled color screen GitHub Universe conference badge

Nov 3, 2025 • Simon Willison

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