GPT-5.4 Pro and GPT-5.5 Pro are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
GPT-5.4 Pro, from OpenAI, has a 1,050,000-token context window and is priced at $30/M tokens input, $180/M tokens output on OpenRouter.
GPT-5.5 Pro, from OpenAI, has a 1,050,000-token context window and is priced at $30/M tokens input, $180/M tokens output on OpenRouter.