OpenAI has released the GPT-5.6 model family, comprising three sizes: Luna (smallest), Terra, and Sol (largest). These models feature a one million token context window, 128,000 maximum output tokens, and a knowledge cutoff of February 16th, 2026. Key updates to the API include programmatic tool calling via JavaScript orchestration, native multi-agent support for parallel task execution, explicit prompt cache breakpoints, and an option to receive unresized images in requests.
* Three model tiers: Luna, Terra, and Sol
* Improved performance in long-running agentic professional workflows
* New API features including programmatic tool calling and multi-agent orchestration
* Three model tiers: Luna, Terra, and Sol
* Improved performance in long-running agentic professional workflows
* New API features including programmatic tool calling and multi-agent orchestration
Simon Willison tests OpenAI's newly released ChatGPT Images 2.0 model using a complex Where's Waldo style prompt involving a raccoon holding a ham radio. By comparing results against previous versions and competitors like Google's Nano Banana, the article evaluates the model's ability to handle high-detail illustrations and specific text elements.
Starlette 1.0 has been released, and Simon Willison explores its new features by leveraging Claude’s skill‑building capabilities. He demonstrates how Claude can clone the Starlette repository, generate a comprehensive skill document with code examples, and even create a fully functional task‑management app complete with database, API endpoints, and Jinja2 templates—all generated and tested by Claude itself. The article highlights the practical benefits of integrating an LLM as a coding agent, showcases the new lifespan mechanism, and reflects on the growing popularity of Starlette as the foundation of FastAPI.
Steerling-8B is an interpretable causal diffusion language model that combines masked diffusion language modeling with concept decomposition, enabling generation, attribution, steering, and extraction of hidden representations. It offers features like block-causal attention and decomposition of hidden states into known and unknown concepts.
Simon Willison discusses Toad, a new terminal coding assistant built by Will McGugan using Textual. It aims to improve upon existing tools like Claude Code and Gemini CLI by avoiding flicker and offering better interaction with terminal output. Toad is currently in private preview, available through GitHub sponsorship.
