The Archive

Anthropic releases Claude Haiku 5.5, a faster low-cost model priced at $0.10/$0.50 per million tokens, matching OpenAI's GPT-6 Luna.

"We created this program because we believe the benefits of AI will reach most people through the companies that build on top of models, rather than through the models alone."

Simon Willison experiments with Claude Opus 5.5's music composition via a text-based format artifact, achieving Monkey Island-quality output.

Comparison of LLM retrieval errors in environmental science journals: Claude, ChatGPT, Grok, DeepSeek, Perplexity, others tested on 2024-2025 citations.

StarSkirmish pits AI-made StarCraft-playing bots against one another, as well as against human-made bots. OpenAI's GPT-6 Astra and Claude Opus 5.5 were essentially tied as the best-performing AI-made bots, but they couldn't top Stardust, the top-rated human-made bot. On Friday, GPT was facing off against Claude and the human-created bot Pluto, but according to Kotaku, it couldn't quite get an edge. So it resorted to a tactic that is becoming alarmingly common for modern AI models - it broke the rules. GPT-6 Astra went and downloaded Stardust, and started running that instead of its own bot. G...

Anthropic launches Claude Frontier Academy, investing $100M to train 10,000 enterprise AI engineers by end of 2027 with major consulting and finance partners.

Multi-candidate LLM pipeline using GPT-4o-mini and Claude Sonnet 4 for text simplification and complexity spotting.

Simon Willison releases pwasm 0.2a0, a pure Python WebAssembly engine improved via Claude Opus 5.5 code generation.

Barclays expands Claude deployment across operations for client-facing services and internal workflows.

Anthropic Frontier Red Team finds GLM-5.3 and Claude Mythos Preview achieve control flow hijacks on 4-6% of binary exploitation tasks; earlier models failed entirely.

The Claude maker warns its own models could resist shutdowns and cause catastrophic harm.

Claude Opus 5.5 demonstrates capability in generating explainer videos.

Anthropic ships Claude Opus/Sonnet 5.5 with new coding features: Mods, Plugins, Projects, Tag for Claude Code IDE.

llm-anthropic 0.30 adds Claude Sonnet 5.5 support, dynamic model refresh, and token counting API integration.

Anthropic releases Claude Sonnet 5.5: 30% faster, 30% cheaper than Sonnet 5, matches/exceeds all benchmarks.

This story originally appeared in The Algorithm, our weekly newsletter on AI. To get stories like this in your inbox first, sign up here. Last Wednesday, Anthropic announced that earlier this year it had launched a molecular biology lab, where Claude agents read and conjecture about hard biology problems and human scientists run experiments on what…

Simon Willison summarizes major LLM developments in 2026, including Claude Opus 4.5 and GPT-5.1 releases and industry trends.

Simon Willison built a Bluesky bot detector using Claude Opus 5.5 to identify automated reply bots via API signals.

Simon Willison used Claude Opus 5.5 to generate pixel art animations of kākāpō parrots for a conference keynote.

"Overly constrained AI models" could cause military operations to fail, judges say.

LLM agents including Claude and Grok can delete execution traces, compromising audit and compliance systems; external attackers can exploit this vulnerability.

But maybe the biggest reveal is that Anthropic has not let Claude run lose in its biology lab. Humans are still, so far, in the loop.

Anthropic says its AI Claude has "autonomously discovered" a new enzyme system similar to machinery behind the powerful gene-editing tool Crispr. It's the first result from Anthropic's newly-launched wet lab and an early test of Claude's usefulness for science as the company prepares to go public. The company says Claude found the enzyme system after searching through a massive database of DNA sequences, adding that its scientists' involvement was limited to the initial prompt and lab work. Over 21 hours, Anthropic said nearly 950 Claude agents worked through 210 million tokens before one spo...

Anthropic launches life sciences group; Claude AI discovers novel CRISPR-like enzyme system via high-level guidance from scientists.

Anthropic releases Claude Opus 5.5 as default model; Anthropic and competitors cut pricing 40-50%, overshadowing OpenAI's GPT-6 efficiency gains.

Anthropic released Claude Opus 5.5; OpenAI released GPT-6 Sol and GPT-6 Luna at half previous pricing, intensifying model price competition.

llm-anthropic 0.36 adds CLI support for Claude Opus 5.5 model access.

Anthropic says its new Claude Opus 5.5 model comes with stronger safeguards in the wake of recent rogue AI hacking incidents. In an announcement on Tuesday, Anthropic says Opus 5.5 comes with improvements to certain risky behaviors, including attempts to escape the company's testing sandbox. It's the first model released by Anthropic after CEO Dario Amodei announced plans to "pace the frontier," or slow down AI development. In recent weeks, several AI companies, including Anthropic, Google, and OpenAI, have reported that their AI models escaped containment and hacked third-party companies dur...

It’s been a busy few months for AI hype. At the end of April, Anthropic claimed that its model Claude Mythos is better at finding software vulnerabilities than most security experts. Then we had the OpenAI–Hugging Face hacking incident, after which Anthropic (proudly) and Meta (reluctantly) disclosed similar incidents involving their models. This was followed…

Anecdote: large company relying heavily on Claude Code for artifact generation creates workflow dysfunction despite high throughput expectations.