#Alucinação

GPT-6 Sol and Luna arrived at half the price of GPT-5.6, Claude Opus 5.5 delivers Fable 5.1 level at $4/$20 with four breaking changes in the API, and Google says Gemini 4 ships before the end of the year. What each one brings that's different, the catches (Luna regresses on agentic coding, Opus default effort dropped to medium), and which one to use now.

TypeSafe launched Jev, the first System One model: it doesn't complete text, it takes your program's state and returns a typed decision in a single parallel pass. No parser, no retries, no broken JSON. In this post: what Jev actually is, why it can't hallucinate (and why that doesn't mean it can't be wrong), the real math on $0.042 per million tokens with free output, the three primitives with running Python code, and the 5 traps the docs themselves admit to.

Grounding isn't RAG, it's the property you want: the answer pinned to data that's yours. The techniques that tether the LLM, structured output with a strict schema, the faithfulness check that runs before delivery to the paying customer, and what will still slip through after all of that.