Simon Willison

Highlight

Simon’s breakdown of the recent AI open letters is a must-read, capturing the growing industry fracture over open-weights, distillation, and the existential anxiety surrounding automated AI research. It provides a sharp, concise summary of where the major frontier labs currently stand on AI governance and regulation.

Posts

Open letters about AI development Simon unpacks the recent flurry of open letters from AI companies, highlighting a Microsoft-led petition defending open-weight models as a safeguard against single points of failure. Interestingly, the Microsoft letter explicitly defends model distillation, whereas Anthropic notably abstained and published their own response calling for a crackdown on the practice. He concludes by pointing to the “Pacing the Frontier” letter, where employees from frontier labs express intense concern over the accelerated progress caused by AI increasingly automating its own research.

condense-json 1.0 Simon is working on getting “braver at releasing 1.0 versions” and just minted the 1.0 release for condense-json, a year-and-a-half-old Python library. The tool compresses JSON by replacing duplicated data strings with a special $r replacement syntax, which he actively uses to optimize SQLite log storage space in his popular LLM CLI tool.

July 2026 newsletter Simon published his sponsors-only monthly newsletter for July. The comprehensive edition covers massive recent model releases like GPT-5.6, Claude Opus 5, and Kimi K3, while also diving into his reignited interest in MCP and his latest personal projects.

Project Pulse

Simon continues to balance high-level commentary on AI industry friction with steady, practical improvements to his local developer tools, demonstrating his ongoing focus on efficient local AI logging with the condense-json updates for his LLM project.