Qwen3.7 Flash 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.
Qwen3.7 Flash, from Qwen, has a 1,000,000-token context window and is priced at $0.03/M tokens input, $0.13/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.