Mistral Medium 3.5 and Ox Alpha are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Mistral Medium 3.5, from Mistral AI, has a 262,144-token context window and is priced at $1.50/M tokens input, $7.50/M tokens output on OpenRouter.
Ox Alpha, from Stealth, has a 1,048,576-token context window and is free to use on OpenRouter.