Mercury 2.5 Preview and KAT-Coder-Pro V2.5 are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Mercury 2.5 Preview, from inception, has a 260,000-token context window and is priced at $0.04/M tokens input, $0.15/M tokens output on OpenRouter.
KAT-Coder-Pro V2.5, from kwaipilot, has a 262,144-token context window and is priced at $0.74/M tokens input, $2.96/M tokens output on OpenRouter.