KOS — FRD: Query Engine¶

Parent: KOS PRD
Owner: Digital Office
Status: Phase 1b

Overview¶

The query engine retrieves relevant knowledge from the graph and optionally synthesises a prose answer using a local LLM.

Functional Requirements¶

FR-QRY-01: Hybrid Retrieval¶

Queries MUST use Graphiti's hybrid search: semantic similarity + BM25 keyword + graph traversal.

FR-QRY-02: Query Modes¶

Mode	Description	Used By
Raw	Returns structured chunks + citations, no LLM	Agent API
Synthesised	LLM composes a cited prose answer	Chat UI

FR-QRY-03: Authority Filtering¶

Callers MAY specify min_authority_score (0.0-1.0) to exclude low-authority sources from results.

FR-QRY-04: Jurisdiction Filtering¶

Callers MAY specify jurisdiction_filter (list of ISO codes). Validated against the systems catalogue. Invalid codes return 400.

FR-QRY-05: Wiki Context Injection¶

If a compiled wiki is available, relevant pre-compiled pages are injected into the retrieval context before LLM synthesis. Keyword scoring with section weighting (jurisdictions 1.4x, systems 1.2x).

FR-QRY-06: Web Search Fallback¶

If internal retrieval confidence is below 0.5 AND the request is in synthesised mode, a DuckDuckGo search is performed as supplementary context. Results are clearly labelled as external.

FR-QRY-07: Confidence Scoring¶

Every query result carries a confidence score: min(citations / 3, 1.0). This is a heuristic — not a calibrated probability.

FR-QRY-08: Conflict Tracking¶

Citation conflicts (contradictory facts from different sources) are tracked in the result. Resolution logic is deferred to Phase 2.

FR-QRY-09: Audit¶

Every query is logged: question, answer, mode, citations, confidence, latency_ms, audit_id.

Performance Requirements¶

Metric	Target
Raw query P95 latency	< 500ms
Synthesised query P95 latency	< 10s (LLM-bound)
Wiki context lookup	< 100ms