Anthropic

GLM-5.3 and the spread of advanced cyber capabilities

Anthropic Frontier Red Team on GLM-5.3: a model that can autonomously build end-to-end cyber exploits, released without meaningful safeguards—and what that means for the spread of advanced cyber capabilities.

Research · AI Safety · Security · Research · AI

Introducing Claude Sonnet 5.5

Anthropic introduces Claude Sonnet 5.5, a faster and lower-cost complement to Opus 5.5 that improves agentic coding and everyday task performance versus Sonnet 5.

Announcement · AI · LLMs · Announcements · Machine Learning

Automating eval design and hillclimbing with Claude

Lance Martin (claude.dev) explains principles for production-like evals with held-out sets, then shows how the claude-api skill’s build-eval and hillclimb commands automate design and overfitting-aware improvement—including cost and performance case studies.

Tutorial · AI · LLMs · Tutorials · Benchmarks

What a task costs on Opus 5.5

claude.dev puts numbers on why two same-priced models can cost very different amounts: every turn resends the conversation, so retries and harness shape dominate the bill.

Blog post · AI · LLMs · Claude · Developer Tools

Claude discovers a novel enzyme system with CRISPR-like repeats

Anthropic’s new life sciences lab reports Claude agents autonomously finding an RT-associated enzyme system (ART) with CRISPR-like RNA-repeat arrays in jumbo-phage DNA—early, still-uncharacterized biology shared to invite follow-on work.

Research · AI · Biology · Research · Machine Learning

How we made claude.ai 3x faster in two weeks

Anthropic’s performance sprint cut claude.ai and desktop p75 time-to-typeable from 3.1s to 0.55s: Claude Tag measured journeys, built benchmarks, and shipped thousands of guarded changes in Slack-driven loops.

Blog post · AI · Performance · Engineering · Web Development

Measurements for understanding the pace of AI development inside frontier labs

Anthropic proposes public metrics for the pace of frontier AI development so outsiders can see what is happening inside labs—beyond marketing and model cards.

Announcement · AI Safety · AI Policy · Research · LLMs

Introducing Claude Opus 5.5

Anthropic’s launch page for Claude Opus 5.5 covers capability improvements, pricing/positioning, and how the new Opus tier fits Claude’s model lineup for coding and agentic work.

Announcement · AI · LLMs · Product Management

Prompting Claude Opus 5.5

Anthropic’s guide to prompting Claude Opus 5.5: how the model behaves, patterns that work for complex agentic and coding tasks, and practical prompt-engineering advice for builders.

Guide · AI · LLMs · AI Agents · Tutorials