GPT-5 Codex and multi-qa-mpnet-base-dot-v1 are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
GPT-5 Codex, from OpenAI, has a 400,000-token context window and is priced by the provider serving it on OpenRouter.
multi-qa-mpnet-base-dot-v1, from sentence-transformers, has a 512-token context window and is priced at $0.005/M tokens on OpenRouter.