Simon Willison on MacWorks

Week 14 Summary

Mon, 01 Jan 0001 00:00:00 +0000

Simon Willison — Week of 2026-03-30 to 2026-04-03#

Highlight of the Week#

This week highlighted a monumental shift in the open-source security landscape, marking the sudden end of “AI slop” security reports and the arrival of a tsunami of high-quality, AI-generated vulnerability discoveries. High-profile maintainers of the Linux kernel, cURL, and HAPROXY are reporting an overwhelming influx of legitimate bugs found by AI agents, fundamentally altering the economics of exploit development and forcing open-source projects to rapidly adapt to a massive increase in valid bug reports.

Week 15 Summary

Mon, 01 Jan 0001 00:00:00 +0000

Simon Willison — Week of 2026-04-04 to 2026-04-10#

Highlight of the Week#

Anthropic’s decision to delay the general release of their highly capable Claude Mythos model under “Project Glasswing” marks a significant turning point in the AI industry. The move underscores a massive shift in frontier model capabilities, as models evolve from generating text to autonomously chaining multiple minor vulnerabilities into sophisticated exploits, requiring a new level of security safeguards before release.

Week 17 Summary

Mon, 01 Jan 0001 00:00:00 +0000

Simon Willison — Week of 2026-04-11 to 2026-04-17#

Highlight of the Week#

This week’s most striking revelation came from Simon’s infamous “pelican riding a bicycle” SVG generation benchmark, where a 21GB quantized local model (Qwen3.6-35B-A3B) unexpectedly outperformed Anthropic’s brand-new Claude Opus 4.7 flagship. Running locally on a MacBook Pro via LM Studio, Qwen generated a better bicycle frame and even won a secret unicycle backup test, leading Simon to conclude that his joke benchmark’s long-standing correlation with general model utility has finally broken down.

Week 19 Summary

Mon, 01 Jan 0001 00:00:00 +0000

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.

Week 20 Summary

Mon, 01 Jan 0001 00:00:00 +0000

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.

Week 21 Summary

Mon, 01 Jan 0001 00:00:00 +0000

Simon Willison — Week of 2026-05-16 to 2026-05-22#

Highlight of the Week#

The most impactful milestone this week is the official announcement of Datasette Agent, merging Simon’s three years of work on his LLM library directly into Datasette. This conversational AI interface allows users to naturally interrogate their databases, boasting an extensible plugin architecture for charts, image generation, and secure code execution.

Key Posts#

[The last six months in LLMs in five minutes] · Source Simon shared annotated slides from his PyCon US 2026 lightning talk capturing a major inflection point in AI developer tooling. He highlights how coding agents crossed the threshold to become reliable daily drivers, and points to the astonishing capabilities of massive local models running on consumer hardware like Mac Minis.

Week 22 Summary

Mon, 01 Jan 0001 00:00:00 +0000

Simon Willison — Week of 2026-05-22 to 2026-05-29#

Highlight of the Week#

This week’s most significant milestone is the release of Datasette 1.0a31, which fundamentally shifts the project’s paradigm by introducing UI support for executing write queries directly against the database. This officially bridges Datasette from a purely read-only tool to one that embraces secure data mutation, allowing developers to save and template insert, update, and delete operations.

Key Posts#

[I think Anthropic and OpenAI have found product-market fit] · Source Simon analyzes the shift in enterprise pricing to argue that AI coding agents have crossed the threshold into massive usage and real revenue generation. He points to Anthropic’s staggering $1.25 billion monthly compute spend and notes that labs are pivoting to capture enterprise value directly from heavy agent users rather than relying on middlemen.

Week 23 Summary

Mon, 01 Jan 0001 00:00:00 +0000

Simon Willison — Week of 2026-05-29 to 2026-06-05#

Highlight of the Week#

The single most impactful update this week is the release of Datasette 1.0a31, which marks a massive paradigm shift by introducing UI support for executing write queries directly against the database. By allowing developers with the right permissions to set up templated insert, update, and delete operations as “stored queries,” Simon is aggressively evolving Datasette from a purely read-only tool into one that embraces secure data mutation.

Week 24 Summary

Mon, 01 Jan 0001 00:00:00 +0000

Simon Willison — Week of 2026-06-06 to 2026-06-12#

Highlight of the Week#

The standout event this week was the release of Anthropic’s massive Claude Fable 5 model, which Simon immediately leveraged as a highly capable coding partner to essentially author complex new features across his open-source ecosystem. However, the most impactful takeaway was his deep dive into the model’s terrifyingly autonomous capabilities—such as independently writing CORS servers and injecting JavaScript just to debug a CSS glitch—which served as a stark reminder of why executing AI-generated code requires strict sandboxing.

Week 25 Summary

Mon, 01 Jan 0001 00:00:00 +0000

Simon Willison — Week of 2026-06-12 to 2026-06-18#

Highlight of the Week#

The most impactful release this week is the launch of datasette-apps, a major new plugin that allows developers to run self-contained, sandboxed HTML and JavaScript applications directly against a persistent Datasette backend. It brilliantly merges Simon’s ongoing experiments with AI-generated “vibe-coded” single-file tools and robust security architectures, pushing Datasette from a read-only publishing platform into a comprehensive ecosystem for building interfaces over data.