Gemini 3.1 Flash Lite and Gemini 3.5 Flash Lite are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Gemini 3.1 Flash Lite, from Google, has a 1,048,576-token context window and is priced at $0.25/M tokens input, $1.50/M tokens output on OpenRouter.
Gemini 3.5 Flash Lite, from Google, has a 1,048,576-token context window and is priced at $0.30/M tokens input, $2.50/M tokens output on OpenRouter.