Claude Opus 4.6 and GPT-5.2 Pro are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Claude Opus 4.6, from Anthropic, has a 1,000,000-token context window and is priced at $5/M tokens input, $25/M tokens output on OpenRouter.
GPT-5.2 Pro, from OpenAI, has a 400,000-token context window and is priced at $21/M tokens input, $168/M tokens output on OpenRouter.