Muse Spark 1.2 and Hermes 4 70B are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Muse Spark 1.2, from Meta, has a 1,048,576-token context window and is priced at $1.25/M tokens input, $4.25/M tokens output on OpenRouter.
Hermes 4 70B, from Nous Research, has a 131,072-token context window and is priced at $0.13/M tokens input, $0.40/M tokens output on OpenRouter.