Simon Willison — Week of 2026-04-18 to 2026-05-01#

Highlight of the Week#

The alpha release of llm 0.32a0 marks a foundational architectural pivot for Simon’s ecosystem of CLI tools. By moving away from a simple text-in/text-out abstraction to one that natively models complex message sequences and typed streams, the library is now future-proofed to handle the realities of modern frontier models. This opens the door for seamless integration of server-side tool calls, multi-modal inputs, and reasoning tokens.

Simon Willison — 2026-05-15#

Highlight#

Simon’s latest AI-assisted project is a lightweight QR code generator built entirely with the help of Claude. It perfectly highlights his ongoing exploration of “vibe-coding” to quickly spin up practical, small-scoped utilities for everyday tasks.

Posts#

[QR code generator] · Source Simon used Claude to write a custom tool for instantly generating QR codes. The utility gracefully handles standard text and URL inputs, and also features a dedicated mode for generating QR codes that connect mobile devices to WiFi networks. It serves as another practical demonstration of using generative AI to rapidly build, iterate, and ship helpful little tools.

Simon Willison — 2026-05-01#

Highlight#

Simon demonstrates the power of mobile AI-assisted development by building a complete, multi-component tracking application entirely on his phone while camping using Claude Code for web. It’s a perfect example of chaining small, sharp tools—Python CLIs, Git scraping, and AI-generated static frontends—into a highly practical personal utility.

Posts#

[iNaturalist Sightings] · Source Simon wanted to consolidate and view his iNaturalist observations across multiple accounts, grouped by when and where they occurred. To solve this, he used Claude Code for web to write inaturalist-clumper, a Python CLI that groups sightings within a 2-hour and 5km radius. He then set up a Git scraping repository to regularly run the tool and generate a clumps.json file hosted via GitHub. Finally, he prompted an AI against his tools repository to build a static HTML frontend that fetches the CORS-friendly JSON and displays the sightings in a gallery with lazy-loaded thumbnails and full-size modal images.

Simon Willison — Week of 2026-05-08 to 2026-05-15#

Highlight of the Week#

The standout development this week is Simon’s rapid adaptation to the latest frontier model capabilities, most notably releasing llm 0.32a2 to expose and visualize the new interleaved reasoning tokens of GPT-5 class models directly in the terminal. This perfectly pairs with his hands-on explorations of embedding LLM calls deeply into developer workflows, such as executing prompts via script shebangs and leveraging models to output rich HTML rather than just Markdown.