AI Weekly 2026-W12

If one word captures AI in 2026-W12, it is "infrastructure" — not the models themselves, but everything required to make them work in the real world. Simon Willison distilled a year's worth of scattered agent engineering lessons into a comprehensive pattern guide. Stratechery declared agents the third paradigm shift for large language models. OpenAI acquired both Promptfoo and Astral within ten days to close environment-management gaps in its coding agent stack. Stripe launched the Machine Payments Protocol (MPP) so agents can spend money autonomously. The entire industry is rapidly shifting from "what can agents do" to "how do agents run reliably, securely, and economically in production."