Rerank

import { createRerankedRetriever, voyageReranker } from '@agentskit/rag'

const retriever = createRerankedRetriever(rag, {
  candidatePool: 20,
  topK: 5,
  rerank: voyageReranker({ apiKey: process.env.VOYAGE_API_KEY! }),
})

createRerankedRetriever(base, { candidatePool?, topK?, rerank? }) pulls candidatePool hits from the base retriever (default 20), re-scores them, and returns topK (default 5). Omit rerank and the default is bm25Rerank.

#Rerankers

• voyageReranker({ apiKey, model? }) — Voyage AI; defaults to rerank-2. Pass rerank-2-lite for cheaper / faster runs.
• jinaReranker({ apiKey, model? }) — Jina AI; defaults to jina-reranker-v2-base-multilingual.
• bm25Rerank — zero-dep fallback.

There is no cohereReranker or bgeReranker export. To call Cohere, BGE, or anything else, pass a custom RerankFn — see Recipe: RAG reranking.

All rerankers are drop-in RerankFn values — they share the same createRerankedRetriever API so you can swap them without changing call sites.

#Related

• Hybrid · Recipe: RAG reranking