Retrieval Modes

Issue #639 formalizes two retrieval paths with explicit module ownership.

1) Interactive Recall Path

• Mode name: interactive-recall-path
• Owner: extensions/memory-hybrid/lifecycle/stage-recall.ts
• Contract: latency-bounded hot path for chat turns
• Policy highlights:
  • strict stage timeout and vector-step timeout
  • budget capped by both autoRecall.maxTokens and retrieval.ambientBudgetTokens
  • HyDE/query expansion skipped by default when queryExpansion.skipForInteractiveTurns=true
  • graph expansion and LLM reranking are disallowed

2) Explicit/Deep Retrieval Path

• Mode name: explicit-deep-retrieval-path
• Owner: extensions/memory-hybrid/services/retrieval-orchestrator.ts
• Contract: richer retrieval for explicit tool requests and deeper analysis
• Policy highlights:
  • uses retrieval.explicitBudgetTokens by default
  • query expansion, graph strategy, RRF fusion, and reranking are allowed
  • graceful fallback behavior is preserved when enrichment steps fail

Policy Source of Truth

extensions/memory-hybrid/services/retrieval-mode-policy.ts defines mode names and allowed behavior. Both owner modules consume this file to avoid emergent, duplicated retrieval-policy logic.