Gemini 2.5 Flash Preview 09-2025 and Grok 4 Fast are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Gemini 2.5 Flash Preview 09-2025, from Google, has a 1,048,576-token context window and is priced by the provider serving it on OpenRouter.
Grok 4 Fast, from SpaceXAI, has a 2,000,000-token context window and is priced by the provider serving it on OpenRouter.