not much happened today

**OpenAI** released **GPT-5.4 mini** and **GPT-5.4 nano**, their most capable small models optimized for coding, multimodal understanding, and subagents, featuring a **400k context window** and over **2x speed** compared to GPT-5 mini. The mini model approaches larger GPT-5.4 performance while using only **30% of Codex quota**, becoming the default for many coding workflows. Pricing concerns and truthfulness tradeoffs were noted, with mixed third-party evaluations on reasoning and resistance to false premises. OpenAI also addressed behavior tuning issues in a recent update. Meanwhile, agent infrastructure is evolving with secure code execution and orchestration tools like **LangChain's LangSmith Sandboxes** and **Open SWE**, inspired by internal systems at **Stripe, Ramp, and Coinbase**. Subagents and secure execution are now key product features, with releases like **Hermes Agent v0.3.0** showcasing plugin architectures, live Chrome control, and voice mode. Research on attention mechanisms, including **Attention Residuals** and vertical attention, is gaining traction.