Mercury 2.5 Preview and Sonar Pro Search 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.
Sonar Pro Search, from Perplexity, has a 200,000-token context window and is priced at $3/M tokens input, $15/M tokens output on OpenRouter.