DeepSeek V3.1 Base and Mercury Coder are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
DeepSeek V3.1 Base, from DeepSeek, has a 163,840-token context window and is priced by the provider serving it on OpenRouter.
Mercury Coder, from inception, has a 128,000-token context window and is priced by the provider serving it on OpenRouter.