agrag.evidence.rerank.reranker_from_settings

reranker_from_settings(settings:RetrievalSettings) -> CrossEncoderReranker | None

Build the reranker the retrieval settings configure, or None.

Never loads the model; loading happens on the first rerank call or an explicit warm_up.

Parameters:

• settings (RetrievalSettings) – The retrieval settings to read.

Returns:

• CrossEncoderReranker | None – A CrossEncoderReranker when rerank is enabled and
• CrossEncoderReranker | None – sentence-transformers is installed. None when rerank is
• CrossEncoderReranker | None – disabled, or when it is enabled but the embed-local extra is
• CrossEncoderReranker | None – missing (one warning is logged; hybrid search runs without rerank).