Weekly digest
Claude Fable 5.1 sets the week's agenda. It leads the Artificial Analysis Intelligence Index at 66, and per task it runs 20% more than Fable 5, even with the 75% cut to cache read pricing. As of September 5, GPT-6 Astra sits 35 points above it on WebDev Arena, 1,797 to 1,762, at the same $40/Mtoken.
The other item a developer will use is computer use, now in beta in Claude Cowork and Claude Code for Pro and Max subscribers on the macOS desktop app. Questions about usage come up again too: the 20x plan's weekly limit works out at 10x, and a reported iOS warning puts a "1.5 more usage" label beside Max effort.
Leading the Artificial Analysis Intelligence Index carries a bill: per task, Claude Fable 5.1 runs 20% more than Fable 5, despite the 75% cut to cache read pricing that shipped with it. At max effort it scores 66 on the index, the top result on Artificial Analysis's board.
Artificial Analysis says it supported Anthropic with pre-release evaluation of Claude Fable 5.1.
As of September 5, OpenAI's GPT-6 Astra sits on top of Code Arena's WebDev leaderboard, 35 points ahead of the recently released Claude Fable 5.1. The gap reads 1,797 to 1,762 on a crowdsourced Elo-style rating.
The write-up credits Astra with reshaping the Pareto frontier as "the best-performing model at $40/Mtoken", pricing that matches the latest Claude model. Fable 5.1 arrived days earlier and took first place in the Artificial Analysis Intelligence Index.
An artifact called "Claude's Nevers", posted by @vivek, gathers the "Never do this" lines from what it presents as the Claude Fable 5.1 system prompt, so a developer building on Claude can read the hard refusals in one place. Neither the artifact nor its provenance is independently verified, and it reaches far beyond the song-lyrics section published on September 2. The file, ANTHROPIC/Claude-Fable-5.1.md, runs 2,196 lines and 40,046 words.
Claude can work your desktop in the background now, clicking, typing and opening apps while you do something else. The beta runs on Pro and Max plans in the macOS desktop app, and it's switched on in Settings → General → Computer use.
The update fixes Remote Control sessions hosted by Claude Desktop or VS Code that stalled for minutes after a tool finished when the connection to claude.ai was degraded. It also fixes Bash failures on some Macs and project settings that didn't save "always allow."
According to a Threads post, Claude Code on iOS will get support for / commands, with no rollout confirmation from Anthropic and the poster asking whether anyone has them already. Running a command in the mobile app means typing its full name: the GitHub issue tracker still listed the missing autocomplete as a known usability gap in March 2026.
The 20x in Claude's top plan applies to the 5-hour limits, while the weekly allowance works out at 10x, so one label covers two meters that scale differently.
The comparison it's set against is Codex. Per the quoted clarification, both Codex plans called 20X apply specifically to weekly usage limits, and there are no "5h limits for both Pro plans". Codex's Pro 20X is described there as "quite precisely 20X the usage of the Plus subscription".
The reported Claude iOS interface puts a "1.5 more usage" warning beside Max effort, giving subscribers a stated usage cost before they choose it. Anthropic's documentation says higher effort uses more tokens and reaches usage limits faster, but it doesn't substantiate the reported multiplier or iOS change.
Federal Judge Rita Lin ruled in San Francisco that the Department of Defense violated the First Amendment by designating Anthropic a supply chain threat. The threat status remains in effect while litigation continues, Bloomberg reports.
The Pentagon placed Anthropic on the blacklist in March after negotiations broke down. Anthropic had sought guarantees that Claude would not be used in fully autonomous weapons systems.
Judge Lin stated that the Defense Department created the designation out of a desire to make a public example of the company.
The Financial Times pins a $200 billion figure on the Wall Street financing Google has assembled around Anthropic, calling it a finance machine in its headline. The rest of the report sits behind the FT's paywall, so the breakdown of that sum stays with subscribers.
