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.

Tech News — Week of 2026-04-18 to 2026-05-01#

Story of the Week#

The intersection of artificial intelligence and national hard power dominated this week as the US government aggressively bypassed its own guardrails to integrate commercial AI into classified military networks. While the Pentagon signed sweeping, consequence-free deals with tech giants like Google and OpenAI, it notably blacklisted Anthropic over supply-chain disputes, even as the NSA secretly utilized Anthropic’s “Mythos” model for cybersecurity. This fractured, frantic procurement strategy highlights a decisive shift: Silicon Valley has largely abandoned its hesitancy regarding military applications, cementing a lucrative, hyper-militarized future for frontier AI development.

Hacker News — Week of 2026-06-13 to 2026-06-19#

Story of the Week#

The week was dominated by the US government’s panicked, abrupt suspension of Anthropic’s Fable 5 and Mythos 5 models over supposed “national security concerns”. The drama quickly devolved from genuine geopolitical tension to regulatory farce when it was revealed that the “jailbreak” triggering the ban was just a standard defensive prompt asking the model to “fix this code”. As Anthropic executives scrambled in D.C. for damage control, the community ruthlessly debated the irony of the company’s “safety superpower” posturing, pointing out how the incident highlights the technological cluelessness of regulators handicapping the very tools defenders use to patch vulnerabilities.

Tech News — 2026-07-11#

Story of the Day#

Apple has filed a major lawsuit against OpenAI, accusing the AI giant of systematically poaching employees to steal trade secrets for its nascent hardware division. The suit claims former Apple engineers brought proprietary technical documents and unreleased device prototypes to OpenAI, exposing deep fault lines in the escalating battle for AI and hardware dominance.

Simon Willison — 2026-07-09#

Highlight#

The standout update today is Simon’s deep dive into the newly released GPT-5.6 family, where he unpacks OpenAI’s new API features like programmatic tool calling and analyzes their latest benchmark rivalry with Anthropic. It is a highly substantive read for developers trying to track the rapidly evolving landscape of agentic workflows and advanced API-level orchestration.

Posts#

The new GPT-5.6 family: Luna, Terra, Sol · Source OpenAI launched its GPT-5.6 flagship models in three sizes (Luna, Terra, Sol) alongside claims of superior long-running agentic performance compared to Claude Fable 5. Simon highlights the fascinating benchmark drama, noting that while Fable 5 beat GPT-5.6 Sol on SWE-Bench Pro, OpenAI recently published an article claiming that ~30% of that specific benchmark is broken. For developers, the most valuable part of the post is Simon’s exploration of new API capabilities, including a built-in multi-agent pattern, explicit prompt cache breakpoints, and “Programmatic Tool Calling” that lets models write JavaScript to orchestrate sub-tools. He also generated 18 different pelican images across the models and reasoning levels to test exact token costs.

Simon Willison — 2026-04-08#

Highlight#

The most substantial piece today is a deep-dive into Meta’s new Muse Spark model and its chat harness, where Simon successfully extracts the platform’s system tool definitions via direct prompting. His exploration of Meta’s built-in Python Code Interpreter and visual_grounding capabilities highlights a powerful, sandbox-driven approach to combining generative AI with programmatic image analysis and exact object localization.

Posts#

Meta’s new model is Muse Spark, and meta.ai chat has some interesting tools Meta has launched Muse Spark, a new hosted model currently accessible as a private API preview and directly via the meta.ai chat interface. By simply asking the chat harness to list its internal tools and their exact parameters, Simon documented 16 different built-in tools. Standouts include a Python Code Interpreter (container.python_execution) running Python 3.9 and SQLite 3.34.1, mechanisms for creating web artifacts, and a highly capable container.visual_grounding tool. He ran hands-on experiments generating images of a raccoon wearing trash, then used the platform’s Python sandbox and grounding tools to extract precise, nested bounding boxes and perform object counts (like counting whiskers or his classic pelicans). Although the model is closed for now, infrastructure scaling and comments from Alexandr Wang suggest future versions could be open-sourced.

Tech News — 2026-04-29#

Story of the Day#

OpenAI is facing a highly disturbing lawsuit from the families of Canadian school shooting victims after the company allegedly overruled its own safety team’s recommendation to report the shooter to law enforcement. According to whistleblowers, OpenAI opted to deactivate the user’s account to protect their privacy instead of flagging the credible threat of gun violence to authorities, even going so far as to instruct the shooter on how to circumvent the ban.

Tech News — 2026-05-05#

Story of the Day#

Apple is facing a harsh reality check on its AI promises, agreeing to a $250 million settlement for misleading iPhone buyers about its delayed Apple Intelligence features. Forced to adapt, the company will reportedly open iOS 27 to third-party AI models, allowing users to swap out Siri for alternative chatbots system-wide.

Hacker News — 2026-06-16#

Top Story#

SpaceX has acquired AI coding startup Cursor (Anysphere) for a staggering $60 billion in an all-stock deal, pushing Elon Musk’s company to a $2.78 trillion valuation. The acquisition signals a massive shift where frontier aerospace infrastructure is aggressively absorbing the top enterprise AI developer tooling to build out a trillion-dollar training ecosystem.

Front Page Highlights#

I Could’ve Rickrolled the FIFA World Cup. All I Needed Was My ID A masterclass in why client-side authorization is practically negligence. A security researcher registered as a football agent on a public portal and bypassed an Angular router to access the live streaming management panel for the 2026 World Cup, exposing live RTMP ingest URLs and stream keys. The writeup is terrifying, hilarious, and a stark reminder that even the highest-stakes global broadcast events run on deeply flawed API architecture.