I asked Gemini, Google’s AI tool, to take the CASX elements (Capability, Autonomy, Scale, and Access) and create an operational definition for each of them that would allow us to apply them to products, product announcements, and related material. The purpose was to provide context and examples for the categories described in the book.
Based on the 2026 research landscape and the CASX framework, here are the criteria for each level and representative examples. Note that Gemini was using its built-in weights and data, so the “2026” date on this is more like mid-2025, when the model was frozen. It should be straightforward to re-do this table with web search enabled and get more up-to-date examples. I kept this version as a “baseline” that we can run a comparison on, perhaps every six months or so.
I asked Gemini to find me five recent papers (or product announcements) for each of the four thresholds for Tool - Actor Gradient: Capability, Autonomy, Scale, and Access (CASX). This is the raw research results. Use at your own risk.
Capability
The demonstrable ability to solve novel problems across diverse domains without specific training.The degree to which a system initiates and pursues multi-step plans without human-in-the-loop confirmation.
Yesterday we heard about the new version of Anthropic’s latest AI, Claude. Named Claude Mythos - replacing the awkwardly-named Claude Capybara that leaked out a few weeks ago when Anthropic mistakenly published its own source code to the internet - the new model is reportedly a “step change” from what we’ve had before.
I’m trying to imagine what that might be like. I am a regular user of the current Claude and (to save money) often “dial it back” to the prior version (Claude Sonnet 4.6). I am perfectly happy with that. What could they be building? Or, have they built?
Today, April 2, 2026, Google’s Deepmind division released a new open source model, called Gemma4. Although I have the ability to run open source (or even commercial) models on my laptop, using Ollama, I typically don’t use those for real work, as they tend to be of “modest” capacity. Not to mention that my laptop, while “top of the line” in 2021, is no longer a strong platform for running a language model of any major size. Or so I thought.
Welcome to the companion website for From Tool to Actor: Artificial Intelligence and Human Extinction Risk. This site will serve as a living extension of the book, with ongoing commentary on developments in AI safety, governance, and risk assessment.
After the book appears, we’ll be publishing regular updates here, organized around the book’s analytical frameworks. Categories include commentary aligned with the book’s chapters, along with cross-cutting themes: “What We Got Wrong” (corrections and updated thinking), “What’s Changed” (new developments since publication), and “Canadian AI” (Canadian-specific developments and policy).