Claude Opus 5(anthropic.com)
1715 points by alvis | 1186 comments
Anthropic announcement page for the Claude Opus 5 model, with the poster linking its system card; the captured page failed to load a PDF.
#system-card on Hacker News
6 stories tagged system-card, newest first.
![Screenshot of www-cdn.anthropic.com: System Card: Claude Mythos Preview [pdf]](https://hn.urlbox.com/shots/renders/2026/4/7/41bab4f5-97a2-4216-a678-7447d06ddf8b.jpg)
System Card: Claude Mythos Preview [pdf](www-cdn.anthropic.com)
811 points by be7a | 610 comments
Anthropic's PDF system card for the Claude Mythos Preview model, documenting its capabilities, evaluations, and safety assessments.
GPT-5.4(openai.com)
960 points by mudkipdev | 754 comments
OpenAI's announcement page for GPT-5.4, shown here as the GPT-5.4 Thinking System Card publication dated March 5, 2026.
GPT-5: Key characteristics, pricing and system card(simonwillison.net)
609 points by Philpax | 270 comments
Simon Willison's blog post covering GPT-5's key characteristics, its place in the OpenAI model family, pricing, and notes from the system card.
Claude 4 System Card(simonwillison.net)
638 points by pvg | 237 comments
Simon Willison's blog post highlighting notable details from Anthropic's 120-page system card for Claude Opus 4 and Claude Sonnet 4.
OpenAI o1 system card(openai.com)
395 points by meetpateltech | 287 comments
OpenAI's system card for o1 and o1-mini describing safety work, external red teaming, and frontier risk evaluations under its Preparedness Framework.