not much happened today

**Cursor** launched **Composer 2**, a frontier-class coding model with major cost reductions and strong benchmark scores like **61.3 on CursorBench** and **73.7 on SWE-bench Multilingual**. The model was improved via a **first continued pretraining run** feeding into reinforcement learning, trained across **3–4 clusters worldwide** by a **~40-person** team. **OpenAI** acquired **Astral**, the team behind Python tools **uv, ruff, and ty**, strengthening its developer platform. **Anthropic** expanded **Claude Code** with messaging app channels for persistent developer workflows. The focus in AI agents is shifting from single agents to managed fleets and runtimes, with **LangChain** launching **LangSmith Fleet** for enterprise agent management emphasizing **agent identity**, **credential management**, and auditability. Other launches include **Cognition's teams of Devins**, **AgentUI** by **lvwerra**, and discussions on agent runtimes with features like **checkpointing** and **rollback**. Security and permissions are emerging as critical constraints in agent system design.