Boris Cherny

ClaudeService Anthropic

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.

x.com ↗·2026-09-16

Fable 5.1Software Anthropic

This model is a pleasure to work with, and I've been using it for everything.

Announcing Anthropic's Fable 5.1 model. Cherny works at Anthropic.

x.com ↗·2026-09-01

Claude Code ArtifactsSoftware Anthropic

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

On the Artifacts feature in Claude Code, the product he created at Anthropic.

x.com ↗·2026-07-02

ClaudeSoftware Anthropic

Super cool way to use Claude https://www.vals.ai/blogs/fable-solves-cyphral-distich

x.com ↗·2026-09-14

Claude Opus 5Software Anthropic

Opus 5 is a great model for coding, data analysis, design, biology, knowledge work.

Launch-day post on Opus 5, focused on it being the least prompt-injectable Anthropic model. Cherny works at Anthropic.

x.com ↗·2026-07-24

ProjectsSoftware

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

x.com ↗·2026-09-17

Threat Intelligence reportOther

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

x.com ↗·2026-09-11

Claude Code /checkupSoftware Anthropic

New in Claude Code: /checkup

Introducing the /checkup command that cleans up a user's Claude Code configuration.

x.com ↗·2026-07-08

OpusSoftware Anthropic

I used Opus 5.5 to formally verify the Claude Agent SDK using Lean. A couple short prompts = 16 PRs fixing various bugs and race conditions.

x.com ↗·2026-09-22

LeanSoftware

I used Opus 5.5 to formally verify the Claude Agent SDK using Lean. A couple short prompts = 16 PRs fixing various bugs and race conditions.

x.com ↗·2026-09-22

TLA+Software

TLA+ also works well. I sometimes combine Lean and TLA+ to look for issues around data flow, concurrency, and state mgmt.

x.com ↗·2026-09-22

Auto modeSoftware Anthropic

The team and I use Auto mode exclusively, and have been for many months. I couldn't imagine going back to permission prompts! Really excited to get this out to everyone.

Announcing Claude Code's Auto mode, which his own team built at Anthropic.

x.com ↗·2026-08-07

WorkplaceSoftware Meta

Instead of meetings, I used Workplace posts (Meta’s internal version of Facebook Group posts) to share thoughts, start discussions, and make announcements.

An essay on working from Japan on a US team; Workplace was his employer Meta's own tool at the time.

borischerny.com ↗·2023-12-10