OpenAI launches GPT-5.6 Sol with four-agent reasoning system

OpenAI has launched GPT-5.6 across ChatGPT, Codex, and its API, introducing GPT-5.6 Sol with a four-agent reasoning system and two lower-cost models as the rollout begins worldwide. According to OpenAI, the GPT-5.6 family introduces a new three-tier lineup consisting of…