# Changes in the system prompt between Claude Opus 4.6 and 4.7

<https://simonwillison.net/2026/Apr/18/opus-system-prompt/#atom-everything>

- Host: [simonwillison.net](https://links.thingelstad.xyz/hosts/simonwillison.net/)
- Saved: April 21, 2026 (2026-04-22T00:09:13Z)
- Record: https://links.thingelstad.xyz/links/1d174141f23a/
- JSON: https://links.thingelstad.xyz/links/1d174141f23a.json

## What Jamie wrote

It is super interesting to see the changes that AI models get between releases.

## Facts

- Kind: [Page](https://links.thingelstad.xyz/kinds/page/)

## Appears in

- [WT345: Weekly Thing 345 / Codex, Headless, Wikiwise](https://weekly.thingelstad.com/archive/345/), Briefly

## Same host

- [Interactive explanations - Agentic Engineering Patterns - Simon Willison's Weblog](https://links.thingelstad.xyz/links/92c76d5af4ef/) (simonwillison.net, March 3, 2026)
- [A quote from claude.com/import-memory](https://links.thingelstad.xyz/links/0c55a3e7235b/) (simonwillison.net, March 3, 2026)
- [Anthropic’s Project Glasswing—restricting Claude Mythos to security researchers—sounds necessary to me](https://links.thingelstad.xyz/links/642a7b3884b4/) (simonwillison.net, April 9, 2026)
- [Anthropic’s Project Glasswing—restricting Claude Mythos to security researchers—sounds necessary to me](https://links.thingelstad.xyz/links/db3d2f24908f/) (simonwillison.net, April 9, 2026)
- [Notes on Pope Leo XIV's encyclical on AI](https://links.thingelstad.xyz/links/fb3bcf08bfae/) (simonwillison.net, May 25, 2026)

## Saved the same week

- [On Ada, Its Design, and the Language That Built the Languages](https://links.thingelstad.xyz/links/64cc1572ae8d/) (iqiipi.com, April 21, 2026)
- [Wikiwise — Build your own Wikipedia](https://links.thingelstad.xyz/links/d4eb583067fd/) (wiki-wise.com, April 21, 2026)
- [Headless everything for personal AI](https://links.thingelstad.xyz/links/105f06c6907d/) (interconnected.org, April 21, 2026)
- [Introducing Claude Design by Anthropic Labs](https://links.thingelstad.xyz/links/0573c40907ec/) (anthropic.com, April 21, 2026)
- [Daring Fireball: 'Community Letter From Tim'](https://links.thingelstad.xyz/links/d32147103f12/) (daringfireball.net, April 21, 2026)

## Elsewhere

- Wayback Machine: https://web.archive.org/web/*/https://simonwillison.net/2026/Apr/18/opus-system-prompt/#atom-everything