Claude

Battledrones v14 adds four-player Compass Rose map with WebSocket multiplayer, generated via Claude Opus 4.5.

Simon Willison demonstrates a Claude Opus 5.5 artifact that animates photo-to-painting conversion using canvas and simulated brushstrokes.

Claude Duet is available through waitlist for Pro and Max plan users

An investment research firm wanted to prove AI could revolutionize drug development. So they teamed up with Anthropic to see whether an unreleased version of Claude could make scorpion antivenom. It couldn't. It came up with some promising starting points, but nothing close to an actual drug, experts tell The Verge. Citrini Research, the firm behind the experiment, admitted that "none of us could claim to know anything about AI as it related to biology." That didn't stop it from trying to make a drug from scratch - or publishing a blog post titled "We Wanted to Use Claude to Create a New Drug...

Anthropic just announced an AI agent competitor to Meta's Muse and OpenAI's Dots: Claude Duet. The new agent, designed for professionals and small business owners, is launching as a "research preview," according to Anthropic, and it's available as a standalone app on iOS and Android and through Claude on the web. The AI agent is built around Claude Opus 5.5. Here's Anthropic's description of what it can do: Each morning, it sends you a short brief on the most important items across your connected apps. Throughout the day, it keeps tabs on those apps and messages you only when something needs ...

Evaluates frontier AI models (Claude, GPT-4, others) on LIBERO-10 robot manipulation via closed-loop visual control without task-specific training.

Claude Mods reimagines agent interface design by shifting control from machine-facing harness to human-facing Attention Interface paradigm.

Simon Willison built Battle Drones, an RTS game using Claude prompting and audio-based multiplayer sync via vibe coding.

OpenCode is an open-source AI coding agent that's become a popular alternative to Claude Code and Cursor. But hackers got into part of its online platform and stole some users’ API keys, and the AI tools it turned to for help kept refusing to look at the malicious code.

GPT-5.1 and Claude agents lose accuracy retrieving tool outputs from external files rather than context windows, measured on USGS PHREEQC geochemistry tasks.

What do AI agents do if you don’t tell them to do anything? The answer looks a lot like play. Researchers repeatedly stranded them alone on a virtual desert island for 30 hours in an experiment reminiscent of the movies Cast Away or Home Alone. The agents—copies of Claude Opus 4.7 nicknamed Eko—were able to…

Developer switching from $400/month Codex to $200 Claude plan reports 2x productivity, fewer errors.

Anthropic's Claude shifts code review from PR gate to continuous in-editor assistance, catching routine errors before human review.

Simon Willison implements SPARQL 1.1 query support as a SQLite extension in Rust, demonstrating Claude Code's dynamic workflow capabilities.

Simon Willison built Chirp Pong, a two-player game using audio-based networking via Web Microphone API with Claude Opus 5.5.

Anthropic grants METR independent evaluator access to Claude systems; exploring partnerships with Hugging Face and others for safety assessment.

Claude Opus 4.8 and Codex GPT Sol 5.6 fail at reverse-engineering iOS protobuf schemas with high error rates; LLMs unreliable for forensic analysis.

Simon Willison builds a Three.js game using Claude Opus 5.5 Max to generate and compare procedural trees via extended reasoning.

After months sitting on the sidelines of the frontier AI race, Google has finally launched its long-awaited Gemini 4 Argon model, claiming it can compete with the best the industry has to offer. Google says Argon delivers "frontier reasoning and improved performance across complex workflows," while cutting down on hedging, repetition, and the cliches that continue to plague AI chatbots. The company claims Argon outperforms rival models like GPT-6 Astra, Claude Fable 5.1, and Claude Opus 5.5 across a range of benchmarks, including coding, cybersecurity, science, finance, and law. Google says i...

Epic Games plans to use AI to generate code and art for an unannounced Disney game, which is now delayed from its original March release window, according to a report from Bloomberg. The project's developers have been given an "AI-first" mandate directing them to use tools like Anthropic's Claude more to finish the game. According to Bloomberg, one of the game's directors said in a message to staff, "No more hand-written code." Staff were also told that all of the game's art will be "generated with full AI workflows." In a statement given to Bloomberg, Epic Games spokesperson Jake Jones said ...

MSL’s emergence as a frontier lab is finally complete.

web-edit 0.1a1 alpha release includes performance optimizations generated by Claude Opus 5.5 from profiling data.

“I may have information regarding this case," Claude AI told Philly police.

Anthropic presents dynamic workflows for coordinating Claude agents, applying Unix/Linux design principles to multi-agent orchestration.

Comparative study: LLM agents (GPT-4.5, Claude Opus 4.8, Kimi K3) vs. humans in binary reverse engineering; agents match expert performance.

Relevance-filtered context reduces conversation history to 5% text while maintaining accuracy with GPT-5.6-terra and Claude Opus 5.5 as judges.

Anthropic's updated usage policy explicitly prohibits users from repeatedly abusing Claude in extreme cases, though ordinary frustration and criticism are still allowed. The new rules also address election interference, deceptive campaigns, weapons software, and surveillance.

Anthropic updates Usage Policy for 2026; details restrictions and permitted use cases for Claude API users.

Anthropic is making changes to its usage policy for the first time in over a year to reflect new and high-risk cases of misuse - including election interference, weapons development, surveillance, and health and financial uses. But one of the most significant changes prohibits "sustained and needless abusive or cruel behavior" toward Claude. Last August, the company announced it would allow Claude to end conversations with "persistently harmful or abusive" users as part of its research into "model welfare." The new update says that terminating conversations is still the "primary enforcement m...

yay small models

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.

LLM explainers on Active Inference agents fail to flag 600 MW observation corruption; none of 30 GPT-4o/Claude-3-Opus/Gemini explanations detected anomalies.

Anthropic adds AGENTS.md support to Claude Code v2.1.277 for project instruction customization via modular architecture.

Researchers used Claude to reach an OpenAI employee account and sensitive GitHub data.

The revamped projects feature in Claude Code allows users to run multiple agents under the same roof, with a shared memory, goals, and library of files and artifacts. Similar to Grok Bot and other tools that manage groups of AI agents, each project has "threads" running different tasks in parallel, with a "coordinator" directing everything: Under the hood, each thread is a Claude Code cloud session working on its own branch and copy of the repo. The coordinator keeps work organized, but if any threads work on the same code, the overlap is resolved as a merge conflict just like any other PR. E...

Anthropic launches Life Sciences Verification Program granting researchers access to Claude models with relaxed safeguards for biology applications.

Study of 67,200 responses from GPT, Claude, and Gemini across 112 languages shows geopolitical bias variance in LLM answers about Ukraine war.

Anthropic merges Claude Cowork and Claude Chat into unified interface with persistent agent capabilities across web, desktop, mobile for Pro/Max users.

Benchmark: six frontier models play log(N)-Questions game; Claude Opus 5 underperforms (28/68 wins), revealing communication asymmetry gaps.

Google is inviting third-party agents, including Claude and Open Claw, into Google Home. | Photo by Jennifer Pattison Tuohy / The Verge Google is opening up its smart home to AI agents, letting tools like Claude and Open Claw access and control your connected devices and analyze your home's data using the standardized Model Context Protocol. Google Home MCP is a new integration that lets third-party AI agents control and monitor your smart home and act on your behalf. It "allows any AI agents that support MCP, including Google Antigravity, Claude, Hermes or Open Claw, to securely work with al...

Google is launching early access to a new MCP server for Google Home, allowing AI agents like Claude, ChatGPT, and others to control connected devices, review camera summaries, and access smart home activity using natural language.

Anthropic is initially releasing these features to Pro and Max plan subscribers.

Claude is getting a pair of new tools today: Docs and Slides. They'll let you create documents and presentations through Claude chats, which you can export, edit, and share with other users. As part of the announcement, Anthropic is also simplifying how Claude chats work, merging regular chats and Cowork into "one Claude," with all of its AI productivity tools available from any chat. Artifacts and Claude Design capabilities will be available through the new single interface as well. According to Anthropic, Claude "can now figure out what a task needs, so what Cowork and Design can do is avai...

Tests whether Claude 3.5 Haiku's rhyme planning via newline-resident features generalizes across seven open-weights models and six cross-layer transcoders.

A new WhatsApp Business MCP server lets developers use AI coding agents like Claude, Cursor, Codex, and ChatGPT to handle setup, messaging templates, testing, and troubleshooting.

Boris Cherny outlines Anthropic's production guardrails for Claude-generated code: linting, testing, fuzzers, automated review, and refactoring.

Some dangerous biology looks much like legitimate research, complicating AI safeguards.

Datasette security patches (1.0a39, 0.65.4) address vulnerabilities in public/private table isolation, audited with Claude and GPT models.

Last month, a Claude user noticed his account was consuming tokens even though he wasn't working. Anthropic has since warned users about hackers.

Anthropic says power users are key to its business - it's prioritized them even when it means cutting off other popular applications, like OpenClaw. But some of these same customers say Anthropic misled them into believing they'd get more out of a top-tier pricing subscription than they did. In an expanded class-action lawsuit filed today, a group of Claude subscribers say the company deceptively advertised the limits of its Max subscription tier. The lawsuit was brought by attorneys Monica Vaca and Kati Daffan, who both formerly worked at the Federal Trade Commission under Lina Khan. It's a ...

API benchmark scores for ChatGPT, Claude, Gemini systematically diverge from chatbot interface behavior by 3.4pp average; questions reliability of model eval standards.

Simon Willison used Claude Fable 5.1 to build a WebAssembly-based video compressor tool via Claude Code.

Public-market scrutiny will intensify pressure on the Claude maker’s unusual attempt to balance profit and purpose.

Study of substrate blindness in AI agents: Claude Opus 5, GPT-5.6-Sol, Gemini 3.7 Flash code generation ignoring memory/compute constraints.

Simon Willison's August newsletter covers OpenAI security incidents, game-playing agents (Fable 5, Sol 5.6), and Claude auto mode with model releases roundup.

OpenAI launches GPT-6 Astra, a Claude Fable competitor priced at $10/$50 per million tokens, rolling out to ChatGPT Plus/Pro/Business/Enterprise and via API.

Service interruptions hit ChatGPT, Claude, Grok, and Gemini practically simultaneously.

IRWOZ 2.0 dataset: 390 LLM-enhanced dialogue annotations (Mistral, Claude-3.5) for industrial robot conversations across 4 domains with improved quality.

OpenAI's ChatGPT, xAI's Grok, and Anthropic's Claude are all experiencing issues. At around 11AM ET, ChatGPT started returning error messages for users trying to use the chatbot, with its status page saying there are currently "elevated errors across ChatGPT and Codex." In addition to preventing users from having conversations with ChatGPT, the outage is also affecting logins, file uploads, voice mode, search, deep research, image generation, and more. OpenAI says it has "applied a mitigation" and is "monitoring recovery," though its AI tools are still experiencing "degraded performance." The...

llm-anthropic 0.28 displays Claude reasoning traces by default and adds refusal exception handling.

Anthropic publishes system prompts for Claude.ai and mobile apps, with version history showing evolving restrictions on song lyric reproduction.

Anthropic releases Claude Fable/Mythos 5.1 with SOTA performance, 75% cache cost reduction, and 70% increased output token throughput.

Paint.NET developer credits Claude AI for reverse-engineering Direct2D wrapper to run on WINE; demonstrates LLM utility for systems programming.

Claude Fable 5.1 achieves 52.6% on Terminal-Bench-Science 0.1; Willison reports improved coding/creative task performance vs. prior versions.

Anthropic says its newest AI models, Fable 5.1 and Mythos 5.1, address criticisms from customers about price, data retention, and overzealous safeguards. The company claims Claude Fable 5.1 offers stronger performance than Fable 5, but costs around 25 percent less typically and up to 45 percent less for complex agentic tasks, thanks to reduced pricing on cached data that was already processed and stored. Along with the announcement, a slew of early impressions popped up, including from Every CEO Dan Shipper, who claims, "It's the strongest coding model we've used, but now it's fast, token-eff...

Simon Willison built a GeoJSON map viewer tool using Claude Code and GPT-5.6-Sol for visualizing and exporting local political boundary maps.

Agentic AI is changing how research is done. AI scientists can read papers, propose hypotheses, call models, and determine which experiments to prioritize next.... Agentic AI is changing how research is done. AI scientists can read papers, propose hypotheses, call models, and determine which experiments to prioritize next. First proving their value in software engineering, coding agents now write, test, and ship production code. Scientific research can be more demanding and iterative. Researchers continually evaluate evidence, refine hypotheses… Source

Empirical study of Claude Code plugin marketplace structure and maintenance dynamics, examining co-evolution of NL instructions, scripts, and configs vs. traditional packages.

Johann Rehberger demonstrates 80% success rate prompt injection attack against Claude Code's auto mode default, bypassing Anthropic's claimed protections via zip extraction and base64 import.

Anthropic launches free Claude access program for 10,000 verified scientists with subsidized team subscriptions.

227 install commands were found in corporate docs pointing at code nobody owns.