/v1/rerank speaks the Cohere v2 rerank shape — a query, a list of documents, a
rerank model — and is the one path on the LLM plane that is not OpenAI-shaped.
/v2/rerank, which the gateway does not serve, so
this path is called with a plain HTTP client.
Which registries can serve it
Cohere, and nothing else. Every other provider is excluded from the pool automatically, so an application that reranks needs a Cohere registry attached — alongside whatever serves its chat, which is fine.How it routes
The pool narrows to Cohere registries; routing runs on what is left. With one Cohere registry that is trivially one target. Pinning anything else is a400, no Cohere registry is a 503.