Simon Willison

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
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
Oct 16

Quoting Addy Osmani, Morgan Westlee Lunt, and Qing Wang

The article discusses a shift in code review practices, moving from a final gate to continuous review that functions like spellcheck during coding. It highlights how the Claude Code team uses the Claude AI to catch routine mistakes before human reviewers intervene, allowing developers to focus on higher-level issues. The piece references insights from Addy Osmani, Morgan Westlee Lunt, and Qing Wang on this evolving approach.

Simon Willison
Aug 24

llm-anthropic 0.27

The release of llm‑anthropic 0.27 updates the Anthropic plugin for LLM to be compatible with the newly released anthropic v1.0.0 Python library, which has switched from httpx to httpx2. This mirrors a similar change made by OpenAI in their v3.0.0 release two weeks prior. The update includes a migration guide and a pull request that ensures tests pass after upgrading to anthropic>=1.

Simon Willison
Oct 22

Quoting Armin Ronacher

Simon Willison reflects on the long history of flawed software development, noting that the proliferation of bad code over the past three decades is now being penalized by the universe. He cites Armin Ronacher’s perspective that the rise of AI, while entertaining, has amplified the consequences of these past mistakes. The piece underscores the growing importance of addressing security and reliability in the age of generative AI.

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
Oct 28

The October inflection point for vibe game development

Simon Willison discusses a new inflection point in October 2026 for creating video games using AI, noting that Claude Opus 5.5 now reliably produces compelling 3D models, music, and especially game design. He reports having successfully "vibe coded" four enjoyable games without inspecting the code, and highlights that the real challenge is now generating novel, delightful concepts that AI alone could not conceive. The author compares Opus 5.5’s fun factor to GPT‑6 Astra, which he finds lacking in that regard.

Simon Willison
Oct 26

Quoting Jason Koebler

The article discusses how users of major tech platforms, frustrated by the lack of human customer support, are increasingly turning to ChatGPT for help with everyday tech issues. ChatGPT is reportedly suggesting that these users have uncovered a noteworthy story and that 404 Media can assist them. The piece highlights the growing role of AI in both troubleshooting and journalism.

Simon Willison
Oct 15

LaTeX renderer

Tool: LaTeX renderer Inspired by Paul Ford and Aboard Foundary's new web app Tiny Little Office, which provides a suite of web app content editors (a Word Processor, Outliner, Presentation Bui...

Simon Willison
Aug 16

Markdown SVG upgrades

I started building my markdown-svg-renderer tool in May , but I've since added enough features to it that it's worth talking about here again. It's evolved into my ideal tool for sharing Markdown transcripts that include SVG documents.

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
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.