DeepSeek V4 Pro 0813 and Claude Opus 5 (Fast) are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
DeepSeek V4 Pro 0813, from DeepSeek, has a 1,048,576-token context window and is priced at $0.435/M tokens input, $0.87/M tokens output on OpenRouter.
Claude Opus 5 (Fast), from Anthropic, has a 1,000,000-token context window and is priced at $10/M tokens input, $50/M tokens output on OpenRouter.