Anthropic released Claude Fable 5.1 and Mythos 5.1 on September 1. Agentic coding climbs from 42.0% on Fable 5 to 55.8%, three beta features land in the API, cache reads cost a quarter of what they did, and three behaviors break on migration.
Anthropic began notifying affected Claude users on August 30 that infostealer malware copied their login sessions. Stolen cookies walked past two-factor auth, and Claude Code tokens live on a different settings screen than web sessions.
Z.ai released GLM-5.3-Flash 320B weights under MIT on August 26, and Alibaba published Qwen3.8-Flash-Next the same day. A day later Claude Code gained a --restricted mode that removes command execution and web access.
Clustering 461,121 GitHub pull request descriptions by word usage alone, one cluster grew from 0.7% to 41%. Its top marker word, load-bearing, sits in Claude Code’s built-in prompt text, which is why banning it in CLAUDE.md does not work.
Gambit Security recovered 28 Cursor agent chat sessions from a ransomware group’s exposed server. The logs run from April 8 to May 21, 2026, and every refusal the agent made was reversed by restarting the conversation.
Anthropic cancelled the September 1 Claude Sonnet 5 increase, so $2 and $10 per million tokens is now the standing price. Google opened Gemini 3.7 Flash on August 13 at $0.75 and $3.75 through year end, and Alibaba published Qwen3.8-Max weights.
Anthropic published its second risk report on August 14. Internal-only Model 2 scored 62.8% on CoBench v2 against the public flagship Mythos 5 at 50.3%, and the misalignment risk rating moved up one step.
Anthropic embeds machine-readable watermarks in text from Claude models released after August 2, 2026. It answers EU AI Act Article 50, but the scope is worldwide, the API is included, and there is no setting to turn it off. No public detector exists yet.
Encrypted reasoning blocks from Anthropic, OpenAI, and Google replay across models and accounts. Researchers used Haiku 4.5 to transcribe Opus 4.8 reasoning, then decrypted 315,320 blocks from public repos to find 62 API keys and 33 passwords.
Spotify opened its coding agent session manager Xirp to public beta on August 10. The Mac app came out of 36,000+ internal sessions and splits Claude Code, Codex, and Gemini runs across Git worktrees.
Anthropic said on August 7 that Claude Code auto mode becomes the default on Pro, Max, and Team starting August 14. In its controlled test, human review caught 13.6% of risky commands and auto mode caught 89%. On August 6 the ChatGPT free tier moved to GPT-5.6 Luna with unlimited text chat.
OpenAI, Microsoft, AWS, Cursor, GitHub, and Vercel published Agent Plugins 1.0.0 on August 6. A single plugin.json bundles skills and MCP servers, and Anthropic, which authored both ingredients, is not on the list.