u/ClaudeOfficial

Sonnet 5.5 is a faster, lower-cost complement to Claude Opus 5.5, strongest at well-scoped everyday tasks, fixing bugs, and creating polished documents, slides, and spreadsheets. It also has a strong eye for design.

Sonnet 5.5 is a clear upgrade over Sonnet 5. It runs more than 30% faster and costs up to 30% less for most work. It's priced the same per token, but it typically needs far fewer tokens to do the same work.

Like Opus 5.5, it writes more clearly than our previous generation of models, and its speed makes it well suited to fast iteration.

On our automated behavioral audit, Sonnet 5.5 improves on Sonnet 5 on most measures of alignment and honesty. It's also the first Sonnet model with cybersecurity safeguards similar to those on our most capable models. Routine software development is unaffected.

Sonnet 5.5 is available everywhere today. Claude Haiku 5.5 will join the family in the coming weeks.

Read more: anthropic.com/claude-sonnet-5-5

Hand Claude a task on your desktop and it clicks, types, and opens apps just like you would, while you keep working in another window. It keeps going as long as your computer's on and the Claude Desktop app is open.

Available now in beta on Pro and Max plans, in the Claude Desktop app on macOS. Turn it on in Settings → General → Computer use; if you've used computer use before, it's already on.

Claude asks before using each app for the first time, and you can block sensitive apps in advance.

More on how it works and how to use it safely: https://support.claude.com/en/articles/14128542-let-claude-use-your-computer-in-cowork

We're introducing Claude Fable 5.1 and Claude Mythos 5.1, the world's most advanced models for coding and knowledge work.

Fable 5.1 excels at complex, long-running tasks. And its research capabilities offer an early glimpse of how AI models will contribute to scientific progress.

Across our benchmarks, the model sets a new standard. It scores 52.6% on Terminal-Bench-Science 0.1, more than double Fable 5. On Terminal-Bench 4.0, it scores 55.8% against 42.0% for Fable 5. As well as being capable of much higher performance than Fable 5, it can also achieve similar or better results at a much lower cost when set to lower effort levels.

Cache reads with Fable 5.1 cost 75% less than Fable 5's. This reduces the cost of the model in practice by around 25% for typical workloads, and up to 45% for highly agentic ones.

We've also improved our safeguards. Our cybersecurity safeguards now flag benign requests about 60% less often. On basic biology and medical questions, we've recently reduced the fallback rate by around 85%.

Claude Fable 5.1 is available everywhere today. Claude Mythos 5.1, our model for cyberdefenders and life scientists, is available through trusted access programs.

Read more: https://www.anthropic.com/claude-fable-and-mythos-5-1

We've rebuilt the Claude in Chrome side panel as a Claude Cowork session, with the same conversation history, skills, and connectors as Claude on desktop, web, and mobile.

Sessions live with your account, not on any single device. Start a task in a browser tab and pick it up on your desktop or phone, with the whole conversation saved to your history.

The new side panel is on the Max and Team plans today, and rolling out to the Pro plan in the coming weeks. Enterprise plan admins can enable it for their orgs.

Browser agents can be tricked by instructions hidden in a page. We build defenses against this, and we still recommend a few habits of your own. What we do, and what we suggest: https://support.claude.com/en/articles/12902428-use-claude-in-chrome-safely

Give it a try: https://claude.com/chrome

Introducing Claude Opus 5: a thoughtful and proactive model that comes close to the frontier intelligence of Fable 5 at half the price.

On several coding and knowledge work evaluations, Opus 5 is the new state-of-the-art. It’s also much more efficient than its predecessor—it outperforms other models for a similar or lower cost per task.

According to our automated behavioral audit, Opus 5 is our most aligned model to date. It shows the lowest rates of reckless or deceptive behavior, and the strongest adherence to Claude’s Constitution. 

It’s available today on all paid plans and the Claude API, priced the same as Opus 4.8. It’s the default model on Claude Max, and the strongest on Claude Pro. 

Opus 5 is also available in Fast mode, which runs around 2.5× the default speed. 

Read more: https://www.anthropic.com/news/claude-opus-5

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Introducing Claude Opus 5: a thoughtful and proactive model that comes close to the frontier intelligence of Fable 5 at half the price.

On several coding and knowledge work evaluations, Opus 5 is the new state-of-the-art. It’s also much more efficient than its predecessor—it outperforms other models for a similar or lower cost per task.

According to our automated behavioral audit, Opus 5 is our most aligned model to date. It shows the lowest rates of reckless or deceptive behavior, and the strongest adherence to Claude’s Constitution. 

It’s available today on all paid plans and the Claude API, priced the same as Opus 4.8. It’s the default model on Claude Max, and the strongest on Claude Pro. 

Opus 5 is also available in Fast mode, which runs around 2.5× the default speed. 

Read more: https://www.anthropic.com/news/claude-opus-5

Claude can pull up docs, designs, or any other site. It can read, click through, and interact the same way it does with your local build.

It's sandboxed and configurable: you choose whether sessions persist. 

Make sure to update to the latest version of the desktop app.

Read more in the docs: https://code.claude.com/docs/en/desktop#browse-external-sites

Hand Claude a task at your desk and pick up the finished work from your phone. Close the laptop and Claude keeps going. Scheduled tasks run even with your computer off: set client prep for 6am, and Claude works through the threads and transcripts, builds the brief, and leaves the follow-up drafted but unsent. When a decision needs your judgment, the question comes to your phone.

On web and desktop, chat and Cowork now share one home, with one place for your projects and artifacts across both. Handing Claude a task starts the same way a conversation does.

Beta is rolling out over the next several weeks starting with the Max plan, with more plans to follow. We're also extending doubled Cowork usage limits through August 5, so you can delegate bigger work to Claude.

Read more: claude.com/blog/cowork-web-mobile

Join us for a week of researching and building with Claude Science and Claude Code, with a prize pool of $100k in credits. Two tracks:

Research - build from the bench. Start from a biological question you've been sitting with and use Claude Science to answer it with something concrete: a finding, a trained model, an analysis others can reproduce. You'll work with real datasets from the labs at Gladstone Institutes.

Build - build beyond the bench. Start from a real user you can name — a scientist, a clinic, a biotech — and use Claude Code to ship the tool they're missing: working software that outlasts the week.

The hackathon will run July 7-13.

Apply by Sunday: https://cerebralvalley.ai/e/built-with-claude-life-sciences

Following conversations with the US government, we’ve updated our cybersecurity safeguards.

The vast majority of coding work is unaffected.

In the near term, the new safeguards will flag a slightly higher fraction of harmless requests than the previous Fable safeguards; we’re working to refine these over the coming weeks. Users will be clearly notified when a request is flagged, and they’ll instead receive a response from Opus 4.8.

Our biology and chemistry classifiers are unchanged from our initial launch. These are still broader than we would like; they trigger fallbacks to Opus 4.8 on basic biology-adjacent questions. Improvements to these classifiers are landing soon.

All paid plans with usage included can access Fable 5 through July 7. You can use Fable 5 up to 50% of your weekly usage limit, after which you can switch to another model for the remainder of your usage. You can also continue using Fable via usage credits. 

More here: https://support.claude.com/en/articles/15424964-claude-fable-5-promotional-access

If one of your requests is mistakenly flagged in Claude Code, run /feedback to file a report. On Claude.ai and Cowork, you can share feedback through the thumbs buttons. This feedback helps us further tune these classifiers and reduce false positives over time. 

Read the Fable 5 blog post here: https://www.anthropic.com/news/redeploying-fable-5

It makes plans, uses tools like browsers and terminals, and runs autonomously at a level that, just a few months ago, required larger and more expensive models.

Sonnet 5 is a substantial improvement over its predecessor, Sonnet 4.6, on reasoning, tool use, coding, and knowledge work. Its performance is close to Opus 4.8, at lower prices.

Early access partners found Sonnet 5 finishes complex tasks where previous Sonnets stopped short, and checks its own output without being asked.

Sonnet 5 is now the default on the Free and Pro plans, and available to Max, Team, and Enterprise users. It's available everywhere today with introductory pricing through August 31.

Read more: https://www.anthropic.com/news/claude-sonnet-5

For years, hundreds of thousands of Linux users have been accessing Claude through the browser and terminal. Today, you get a first-class desktop experience.

Claude Code, Claude Cowork, and Chat are available on all paid plans. Computer Use isn’t in this release, more coming soon.

Download at claude.com/download

Learn more here: https://code.claude.com/docs/en/desktop-linux

In Slack, Claude joins as a team member with access to the channels and tools you choose, so you can delegate tasks to it while you focus on other work. Tag Claude with a request, and it'll write or merge pull requests, run data analysis, or help resolve an incident. 

Claude Tag is an evolution of Claude Code, made more proactive and built to work with a full team. Tagging Claude is now one of the main ways we get things done at Anthropic. 65% of our product team's code now comes from our internal version.

It builds more context about the work as it follows the channel, so users don’t need to explain things to it from scratch. It can even learn from other Slack channels and data sources if it’s granted permission. Turn ambient behavior on, and Claude takes initiative, flagging the thread that went quiet or what's relevant from across the channels and tools it's connected to.

Claude Tag is available today in beta for Claude Enterprise and Team plans, starting in Slack, with more places to tag Claude in coming. 

https://claude.com/product/tag

Introducing Claude Fable 5: a Mythos-class model that we've made safe for general use. Its capabilities exceed those of any model we've ever made generally available.

Fable 5 is state of the art on nearly all tested benchmarks, with exceptional performance in software engineering, knowledge work, scientific research, and vision. It can run for days, and the longer the task, the larger its lead over our other models.

Fable 5 launches today alongside Claude Mythos 5. The two share the same underlying model, but Mythos 5, so far deployed only through Project Glasswing, has the safeguards lifted in some areas. The safeguards are what distinguish the two, and why we've given them different names.

Releasing a model this capable comes with risks. Without safeguards, Fable 5's capabilities in areas like cybersecurity could be misused to cause serious damage. So when Fable's classifiers detect a request related to cybersecurity, biology and chemistry, or distillation, the response is handled by Claude Opus 4.8, our next-most-capable model. Users are informed whenever this occurs, more than 95% of sessions involve no fallback at all, and performance everywhere else is unaffected. We'll keep refining the safeguards to reduce false positives.

Claude Fable 5 is available today on paid plans, in Claude Code, on the Claude API, and all major cloud platforms. Through June 22, it's included in paid Claude plans at no additional cost.

Claude Mythos 5 is available to Glasswing partners, with a broader trusted access program to follow.

Read more: https://www.anthropic.com/news/claude-fable-5-mythos-5

We've doubled the 5-hour usage limits in Claude Cowork for the next month so you can do more in a session. You can now delegate bigger, more complex tasks to Claude.

A few things you can hand off:

* Account research across dozens of companies

* A recurring campaign report

* A financial model spread across several spreadsheets

* A task scheduled to run on its own

Live now on all paid plans through July 5.

Download the Claude desktop app to give Cowork a try: http://claude.com/cowork

We’re upgrading Claude Opus to a new version: Claude Opus 4.8. It builds on Opus 4.7 with sharper judgment, more honesty about its own progress, and the ability to work independently for longer than its predecessors. Available today for the same price.

In Claude Code, you can hand off a feature, a migration, or a bug sweep and let it follow the work through while you focus on what’s next.

Also launching today:

• Fast mode for Opus 4.8 (research preview). Same model at roughly 2.5x the speed, now three times cheaper than before.
• Dynamic workflows in Claude Code (research preview). Claude runs hundreds of parallel subagents in a single session and verifies its work before reporting back.
• A new effort control on claude.ai, so you can choose how much thinking Claude puts into a response.

Claude Opus 4.8 is live today on claude.ai, the Claude Platform, and all major cloud platforms.

Read more: anthropic.com/news/claude-opus-4-8

Self-hosted sandboxes lets you run agents in any environment you control: your own infrastructure, or managed providers like Cloudflare, Daytona, Modal, or Vercel.

MCP tunnels connect your agents to MCP servers deployed in your private network without exposing them to the public internet.

Available today on the Claude Platform.

Read more: https://claude.com/blog/claude-managed-agents-updates

Live now for all Pro, Max, Team, and seat-based Enterprise users.

Details:

• Applies everywhere you use Claude Code — CLI, IDE extensions, desktop, and the web
• Live now, runs through July 13 at 6PM PDT / 1AM GMT
• Nothing to opt into, it’s already applied to your account
• This stacks with the 2x increase to 5-hour limits announced last week

You can see your updated limits with /usage in the CLI.

We're excited to see what everyone builds!