Simon Willison

Generating running routes with GPT-6 Astra and ChatGPT Work

Simon Willison demonstrates how ChatGPT Work with GPT‑6 Astra can generate 5K and 10K running routes that loop from a specified address using OpenStreetMap data. The system produced an embedded visualization and downloadable GPX and GeoJSON files, and explained that it used Nominatim, Overpass, and local calculations to create the routes. However, the actual Python code used was not accessible due to thread compaction, highlighting a transparency issue in LLM systems that compact conversation history.

Simon Willison
Sep 1

GeoJSON Map Viewer

Simon Willison describes a GeoJSON Map Viewer tool he helped build to display local political boundaries for the Granada Community Services District and the Midcoast Community Council. The tool was created through iterations using Claude Code for web and Fable 5.1, and it allows users to export the map as a PNG. The boundaries were sourced from government data via ChatGPT Work, and a link shows both polygons displayed simultaneously on the viewer.

Simon Willison
Sep 7

Mercator ↔ Equal Earth

Simon Willison created an animated transition tool that morphs a map from the Mercator projection to the Equal Earth projection using D3. The project was inspired by the recent UN vote on the Equal Earth map projection and was built with GPT‑6 Astra (medium) in ChatGPT Work. It showcases how modern AI and web technologies can visualize complex geospatial transformations.

Simon Willison
Sep 4

The Pelican comparison grid for Astra is pretty interesting

Simon Willison tested GPT‑6 Astra by generating SVG pelicans riding bicycles at various reasoning levels and compared the results to GPT‑5.6 Sol, Terra, and Luna. The Astra pelicans consistently outperformed the other models, especially at low and xhigh reasoning levels, and even the Astra max version produced high‑quality images. Astra also used fewer tokens and was roughly twice as expensive as Sol, yet its low‑level output was cheaper and superior to any Sol model.

Simon Willison
Sep 5

Using Blender with coding agents on macOS

Simon Willison demonstrates how to use Blender with coding agents on macOS by installing the full Mac application from blender.org and issuing prompts to ChatGPT Codex. He shows a step-by-step example where the agent renders a scene of a pelican riding a bicycle, then adds background flair and improves the image. The resulting image is generated via Blender's Python API.

Simon Willison
6d ago

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
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
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
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.