Claude Opus 5 (Fast) and Qwen3.8 27B are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
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.
Qwen3.8 27B, from Qwen, has a 1,000,000-token context window and is priced at $0.35/M tokens input, $2.75/M tokens output on OpenRouter.