Semantic API

The Semantic surface searches the corpus by meaning rather than literal terms. It runs dense (PrIx-native μ embeddings) and sparse (TF-IDF) vectors over the same passages, then fuses them with Reciprocal Rank Fusion. Use it when the caller has a question or a fragment of plain text instead of a precise KWS query. Passage segmentation is exposed via the same surface because it shares the embedding store.

Method	Path	Summary	Key params	Response
POST	/semantic/explain	Per-line evidence for a set of pages	body: ExplainRequest	ExplainResponse
POST	/semantic/search	Semantic search (dense embedding + optional sparse hybrid)	body: SemanticSearchRequest	SemanticSearchResponse
POST	/semantic/search-with-lines	Semantic search + per-line evidence in one call	body: SearchWithLinesRequest	SearchWithLinesResponse

Examples

Semantic search by free text

curl -H "X-API-Key: $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query": "plague outbreak measures", "limit": 20}' \
  "$ARCHAIC/semantic/search"

See also

• /docs/concepts/probabilistic-indexing/