Boris Cherny

Projects have changed not only how I interact with Claude but how I code.

I stopped managing sessions. I just send thoughts as they come, Claude splits them into threads, and the project remembers how I work. It's where I do a ton of my coding now.

[screenshot: my actual prompts for claude code cli yesterday]

Projects are how I write a lot of my code these days. Really excited for everyone to try the new experience! Rolling out now

Also today: Claude Docs, Claude Slides, and Claude Design are in every conversation.

Ask Claude for a presentation and you get one you can open, edit, and export as PowerPoint or PDF. Same for a document or a design. There's no separate tool to navigate to. They're just in the chat.

Claude Code showed that AI could do real work, not just answer questions. Developers hand Claude a feature, come back to shipped code. That's where much of the industry's serious engineering runs now.

Cowork proved knowledge workers could do the same: hand Claude the brief, come back to finished files.

Today, chat and Cowork start merging into one Claude. The direction: one Claude that carries context across everything you're working on, wherever you are. Simple enough for everyone to access Claude's full capabilities.

I've been using this experience every day for the last few weeks, and it feels awesome. Simpler, faster, and more powerful.

We're rolling this out slowly. We'll be fine-tuning the experience as we go to ensure it is fast and reliable. Can't wait to hear what you think.

Claude Mods are landing now. Someone already built a Tetris-in-Claude mod 🤯

See issue for the latest community update, technical details, and more cool demos

The latest Threat Intelligence report is an absolutely terrifying and important read.

As models become more intelligent, without the right safeguards and monitoring they also become more dangerous. Many capabilities are dual use: a model that codes well can be used to hack critical infrastructure; a model that assists with biology research can also be used to engineer the next pandemic.

These issues are complex, thorny, and increasingly important for everyone to understand so that the world can weigh in and respond to rapidly escalating risks.

Every day, I get a lot of of emails and messages like this one. I try to respond to as many as I can.

Sharing my response below, for anyone else in a similar situation. What do you think?

Hey ████,

I think there is room for both.

1. Prototypes and other throw-away code can be treated as totally black box. If you’re going to throw it away anyway, and if the blast radius of it breaking is low, it doesn’t need to be perfect.
2. Production code written by Claude should have a higher bar than if it was written by a human. At Anthropic, we have many guardrails in place to make sure this is happening: lots of lint rules, lots of tests, Claude-driven end to end tests, Claude-powered fuzzers running daily, automated code reviews and security reviews, automated code refactoring, and so on. Without these, you can end up with a mess that is hard to maintain down the line. Luckily, the model makes it increasingly easy to do these well — run a few daily routines, use Claude Code Review, etc.

Your job is to hold the bar on code quality. If Claude’s code doesn’t meet the bar, try:
- Using the latest frontier model (Opus 5 or Fable 5.1)
- Increase effort to high or xhigh
- Invest in your CLAUDE.md and skills to succinctly teach Claude how to work in your codebase

If all else fails, steer Claude more when you work with it, or have Claude fix accumulated debt and rewrite your codebase to make it easier to work with. Or, wait for the next model.

Best,
Boris

wait what

Just landed: /diff is now a persistent pane that you can scroll and click. It updates in real-time.

For the times when you want to see the code without having to switch windows.

Enjoy!

The small quality of life improvements keep coming. When you’re using Desktop every day, slow startup makes the app feel sluggish. Working on improving this even more!

Small quality of life improvements like this add up. More on the way

New in Claude Code: /checkup

Run /checkup to:

1. Clean up unused skills/MCPs/plugins and save context
2. Dedup your local CLAUDE.md against the checked in CLAUDE.md
3. Break up root CLAUDE.md into nested CLAUDE.md's + skills
4. Turn off slow hooks
5. Update your Claude Code to the latest version
6. Enable auto mode by default
7. Pre-approve frequently denied read-only commands

.. And a few other goodies.

/checkup confirms with you before making any changes. Enjoy!

Here's what happened when I ran /checkup

This is our first time telling the story of how we first built and launched Claude Code, starting with its origins in Anthropic safety research.

So much more to do. We are 1% done.

Artifacts in Claude Code have been life changing. Excited to expand to Pro and Max!

Agree