Archive - Simon Willison’s Newsletter

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 •

October 2025

Building a tool to copy-paste share terminal sessions using Claude Code for web

Plus Living dangerously with Claude, and prompt injection risks for ChatGPT Atlas

Oct 24 •

Claude Code for web - a new asynchronous coding agent from Anthropic

Plus OpenAI's new browser, and getting DeepSeek-OCR working on an NVIDIA Spark via brute force

Oct 21 •

Claude Skills are awesome, maybe a bigger deal than MCP

Plus Claude Haiku 4.5

Oct 17 •

NVIDIA DGX Spark: great hardware, early days for the ecosystem

Plus Claude can write complete Datasette plugins now

Oct 15 •

Vibe engineering

Plus news from OpenAI DevDay, GPT-5 Pro, gpt-image-1-mini, and Python 3.14

Oct 8 •

Embracing the parallel coding agent lifestyle

Plus prompt injection attacks against Sora 2 cameos and notes on DSPy and Litestream 0.5.0

Oct 6 •

Designing agentic loops

Plus coding agent PR stats and AI-assisted tooling that finds genuine security issues in curl

Oct 2 •

September 2025

Claude Sonnet 4.5 is probably the “best coding model in the world” (at least for now)

Plus video models are zero-shot learners and reasoners

Sep 30 •

GPT-5-Codex, plus updated Gemini 2.5 Flash and Flash Lite

And a flurry of new models from Qwen

Sep 25 •

I think "agent" may finally have a widely enough agreed upon definition to be useful jargon now

Plus GPT-5-Codex, Qwen3-Next-80B, Claude Memory and more

Sep 18 •

Claude's new Code Interpreter

Plus: Recreating the Apollo AI adoption rate chart with GPT-5, Python and Pyodide

Sep 9 •