Simon Willison

Claude Cowork and chat are now one Claude

Claude Cowork and the standard chat interface are merging into a single Claude experience, allowing users to hand over tasks or ask quick questions that the system will continue to handle even after the laptop is closed. The rollout will begin with Pro and Max plan users across web, desktop, and mobile, and will extend to new users on these plans over the coming weeks. This integration suggests Claude is evolving into a general agent, simplifying the distinction between Cowork and regular Claude usage.

Simon Willison
Aug 21

Stop Making TUIs

Stop Making TUIs Thomas Ptacek advocates for building real native user interfaces for even the smallest of personal tools, because coding agents have reduced the cost of getting a usable-enough GUI up and running to almost nothing. I wrote about my vibe-coded bandwidth and GPU monitoring macOS task bar apps back in March , and I'm still using both of those on a daily basis.

Simon Willison
Sep 5

Introducing GPT-6 Astra for developers

Simon Willison introduces GPT‑6 Astra, a new model that offers improved attention to detail, better prompt comprehension, and the ability to generate more sophisticated outputs. The model excels at creating 3D renderings, producing detailed scenes such as gardens, shipyards, animals, cityscapes, and even Dyson spheres. Willison highlights its whimsical creativity, noting examples like a pelican wearing a red neckerchief riding a bicycle.

Simon Willison
Sep 11

Quoting Boris Cherny

The article discusses how production code generated by Claude, Anthropic’s AI, should meet higher standards than human-written code. Anthropic enforces this through numerous guardrails such as lint rules, extensive testing, Claude-driven end‑to‑end tests, daily fuzzers, automated code and security reviews, and automated refactoring. These measures aim to prevent the code from becoming difficult to maintain.

Simon Willison
Sep 11

Feeling sad about AI

Simon Willison reflects on the emotional impact of AI tools that can produce code quickly, noting that many developers experience an initial sense of disheartenment. He argues that recognizing the shift from coding to higher‑level problem solving allows experienced engineers to leverage new tools and add greater value. Willison emphasizes that software engineering has always faced rapid change, so adapting to AI is part of the profession’s ongoing evolution.

Simon Willison
4d ago

Quoting Thariq Shihipar

The article announces that Claude Code will now support AGENTS.md files starting with version 2.1.277. If a CLAUDE.md file is absent in a folder, Claude will automatically look for and use AGENTS.md, leveraging Claude Code mods to customize the harness. The built‑in mod is available for use, and users can also create their own custom project instructions.

Simon Willison
Aug 22

Quoting Linus Torvalds

The article recounts a challenging debug session that was significantly aided by an AI assistant. Despite the AI initially claiming the problem was unsolvable and suggesting a report be written instead, it persisted, adding debug code and analyzing it as the author pushed forward. Ultimately, the author credits the AI with writing the commit message for the fix.

Simon Willison
Aug 25

EVE Online: The Move to Python 3 Begins!

EVE Online is beginning its transition to Python 3, a move that will involve using the futurize script on 2.4 million lines of code and a manual review of about 20,000 differences between Python 2 and Python 3. The company has historically run on Stackless Python since 2003, with the last major upgrade in 2010 to Stackless Python 2.7. While the announcement does not detail how Stackless will be replaced, the team previously showcased a shift away from Stackless in their Carbon engine for EVE Frontier, leveraging the open‑source carbonengine/scheduler library.

Simon Willison
Aug 23

Quoting Drew Breunig

The article reflects on the shift in perspective after the release of Fable, a new model that promised to solve many coding challenges at a comparable or lower cost. Prior to Fable, developers felt it was pointless to invest heavily in coding tools or context strategies, as newer models would likely render them obsolete. However, Fable’s performance was so impressive that, despite its high cost, it prompted a reevaluation of how work was distributed across different models such as Opus, 5.6, K3, and GLM.

Simon Willison
Aug 30

Understanding ChatGPT Work

OpenAI launched ChatGPT Work on July 9, offering two distinct products: Work Cloud, accessed via chatgpt.com or the mobile apps, and Work Local, available through the desktop app that can run programs on a user’s computer. Work Cloud is a paid‑only feature for $20/month and up subscribers, providing advanced capabilities such as code execution with internet access, a headless Chrome browser, and a persistent filesystem across sessions. The author notes that while ChatGPT Work claims to be better for tasks with clear outcomes, many users find the distinction unnecessary and prefer the standard Chat interface for most use cases.

Simon Willison
Sep 4

August newsletter is out

Simon Willison announces that the August edition of his sponsors‑only monthly newsletter is now available. The issue covers topics such as OpenAI’s accidental cyberattacks, new game releases, Claude auto mode, ChatGPT work model updates, and miscellaneous projects and tools he’s using. A preview of the July newsletter is also provided, and sponsors can access the full content for $10 per month.

Simon Willison
5d ago

How To Write With An LLM

The article "How To Write With An LLM" by Thomas Ptacek explains how to use large language models (LLMs) as copyeditors rather than writing assistants. Ptacek advocates a strict rule: never use any single word or phrase suggested by an LLM, treating it as intellectual personal protective equipment. He shares his own practice of using LLMs for fact‑checking, spelling, grammar, and occasional thesaurus help, and provides a screenshot of his personal LLM copyediting tool along with a prompt to help readers build their own.