OpenAI just dropped GPT-5.5 and GPT-5.5 Pro live on OpenRouter, pushing state-of-the-art performance for long-running tasks across code, data, and tools. This follows the GPT-5.4 release in September 2025, ramping up agentic coding and reasoning capabilities in a unified API gateway that simplifies LLM access for developers chasing AI industry impact and OpenRouter integration. Greg Brockman flagged the Pro version's edge in complex analysis, positioning it as a game-changer for knowledge work amid GPT-5.5 release buzz.