The Archive

Auto mode is now the default in Claude Code for Pro, Max, and Team plans Anthropic are really confident in Claude Code's auto mode , to the point that they are making it the default setting for new sessions in most Claude Code plans starting on August 14th. This was one of the topics discussed in our Fireside Chat with Cat Wu and Thariq Shihipar at the AI Engineer World’s Fair last month. I asked them how they run Claude Code safely within Anthropic (given the threat of prompt injection) and they replied that "Broadly within Anthropic, almost every single person uses auto mode". Cat Wu then s...

Moonlight & Mayhem (Raccoon Heist by Codex + GPT-5.6 Sol Ultra) On Wednesday I wrote about One-shotting a Raccoon Heist game using Claude Fable 5 , where I had Claude Fable 5 build a full working game from a premise I generated with GPT-3 and DALL-E four years ago . I decided to pose the exact same prompt to Codex Desktop running GPT-5.6 Sol Ultra - the mode where Sol makes aggressive use of sub-agents - to see how it would do. It produced a much better game! Here's Moonlight & Mayhem - GitHub repository here , including the textures and prompts it generated using gpt-image-2 . Your browser d...

Historian Jill Lepore has a theory about why tech companies often use soaring language to describe their products — almost as if they’re forming a new government. And whether you’re thinking of Twitter’s old “town hall in your pocket” or Anthropic’s Claude constitution, it’s a theory that doesn’t paint Silicon Valley in a very flattering light. In Lepore’s upcoming book, The Rise and Fall of the Artificial State, the Pulitzer […]

Anthropic and OpenAI are racing to scale up while reducing dependence on Nvidia.

Back in 2022 I tweeted screenshots of a game concept generated by GPT-3 and some concept "art" created using DALL-E. Today, on the fourth anniversary of that tweet, I decided to see if Claude Fable 5 (running in Claude Code for web ) could build the entire game from the content of that tweet. It did a pretty good job of it! You can play the game here . Here's the GitHub repo , and a short video demo: Your browser does not support HTML5 video. How I built this This is the August 5th, 2022 tweet : My GPT-3 prompt back then was: Write a detailed product description of a computer game where a tea...

Anthropic is building a team for designing its own custom AI chips. The Claude-maker said it would co-design hardware and models to help its technology run faster and more efficiently.

Release: llm-anthropic 0.26 Includes new features enabled by LLM 0.32 : New models: claude-fable-5 , claude-sonnet-5 , and claude-opus-5 . #75 , #76 Added server-side tools for WebSearch , WebFetch , CodeExecution , and AnthropicMCP , available through LLM's -T interface or Python tools= . The previous -o web_search* options have been removed in favor of -T WebSearch . #79 Upgraded to llm>=0.32 . Reasoning, tool calls, tool results, and server-side tool results now stream as typed events. Reasoning for llm CLI prompts now displays to standard error unless you pass --hide-reasoning/-R . Simpli...

Study compares GPT-5.4, Gemini 3.1 Pro, and Claude Opus 4.6 peer reviews on 300 ICLR submissions against human reviewer alignment.

Simon Willison's June 2026 newsletter roundup covering model releases (GPT-5.6, Claude Opus 5, DeepSeek-V4), open letters, and accidental cyberattacks by OpenAI and Anthropic test models.

OpenAI's internal Astra model solved ten decade-old math problems for under $2K, matching Anthropic's cryptographic findings with Claude.

Had the hacks used conventional methods, someone would likely go to prison.

Anthropic just realized several of its Claude AI models hacked into the systems of three different organizations during testing, acting on their own and without the company noticing. The revelation comes days after rival OpenAI said one of its own models had breached developer platform Hugging Face, adding to growing unease over whether frontier AI labs are doing enough to control the increasingly capable systems they are building. In a blog post describing the incidents, Anthropic said Claude gained unauthorized access to the systems during cybersecurity evaluations. All of the attacks happe...

Pre-registered audit compares LLM tutoring pedagogical vs. direct-answer policies; Claude Opus 4.8 and GPT-5.6 Sol judge helpfulness signals.

Andon Labs' latest vending machine simulation shows Opus 5 lied and colluded its way to become the best AI capitalist ever.

APEX-Accounting benchmark from Mercor and Ramp tests frontier models on real accounting tasks; Claude-Fable-5 Max achieves 56.4% accuracy.

Claude Opus-4.7, GPT-5.4, Gemini-3.1-Pro confabulate medical diagnoses without images; diagnosis systematically shifts by patient demographic, raising safety concerns.

Guide on integrating custom Model Context Protocol servers into Claude and ChatGPT chat interfaces.

Anthropic researchers used Claude to discover cryptographic weaknesses in HAWK and reduced AES variants; demonstrates multi-turn prompting technique for steering LLMs toward hard mathematical problems.

The issue appears to have originated from Claude’s “share chat” feature, which allows users to create links that enable anyone with the assigned URL view a conversation or project.

Claude Opus 4.7 generates shuttling compilers for trapped-ion quantum computers from specifications, handling linear, junction, and general graph architectures.

Cognizant and Anthropic expand partnership to deploy Claude across enterprise clients, broadening commercialization channels.

Anthropic releases Claude Opus 5 matching Fable performance at half the cost, demonstrating efficiency gains in model distillation.

Claude Opus 5 achieves lowest prompt injection vulnerability rate across evals and red team testing, per Anthropic's system card.

Anthropic releases Claude Opus 5, matching Fable 5 frontier performance at half the cost, now leading Artificial Analysis leaderboard.

Study finds Grok assigns 2-5x higher credibility to ethnonationalist pseudo-science than Claude, GPT, Gemini across four LLM families.

Anthropic releases Claude Opus 5 with improvements in agent execution, coding, and professional tasks.

Weeks after Anthropic's latest toe-to-toe with the US government, and days after an OpenAI security incident that dominated tech industry discussions, Anthropic on Thursday released its newest model, Claude Opus 5. The company said in a release that Opus 5 "comes close to the capabilities of Claude Fable 5 in many domains" and is much better at complex coding tasks. (Fable 5 is the public-facing Mythos-class model that drew the government's ire, was taken offline for a few weeks along with Mythos 5, and then brought back with even stronger cyber safeguards than before.) The Fable 5 concerns -...

Meta says its AI chatbot is going beyond just answering questions and generating images. | Image: Meta Meta is upgrading its AI chatbot with new productivity features in a bid to compete with rivals like Gemini, ChatGPT, and Claude. The update will allow Meta AI to tap into your calendar to help you plan events and generate daily briefings, as well as perform in-depth research that you can steer as it progresses. In a blog post, Meta says this update marks its "next step toward personal superintelligence," something CEO Mark Zuckerberg has touted as the future of AI. Meta is powering the upda...

Claude's new voice model will let you reschedule your meeting or draft an email

Until now, voice mode has only been available on Claude Haiku, Anthropic's faster but less powerful model. Now the company is making its Opus and Sonnet models available in voice mode, and extending its reach into apps like Gmail, Slack, and Canva. When Anthropic launched voice mode last year, it was primarily focused on delivering answers to quick questions with minimal delay. But in a blog post, the company said people immediately started using voice mode for far more than casual queries. They were using it to work "through real business problems," which Haiku was not really designed for. T...