Module retriever 

The retrieval pipeline: plan in, prepared snapshot out.

Search order is L0 prepared-query cache → session overlay → canonical BM25 → optional semantic fallback. Each stage is cheaper than the next, and the expensive one is reached only when the cheap ones genuinely could not serve the query.

Structs

IndexHandle

Shared, swappable index state.

LocalMemoryRetriever

The default retriever: local, in-process, no network on the happy path.

RetrievalBudget

A time budget for a retrieval.

RetrievalRequest

A request to prepare context for a turn.

Traits

MemoryRetriever

Prepares and serves memory context.

SemanticFallback

An optional paraphrase-tolerant backend.