Vectors, geo and RAG search. Substrio docs

{"where": {"embedding": {"$knn": {"vector": [0.1, 0.2, 0.3], "k": 10}}}}

Indexing a vector field

Declare a vector index before querying it, with index.create (kind: "vector", POST /v1/_indexes):

Field	Type	Default	Description
`collection`	string	required	The collection
`field`	string	required	The vector field
`dims`	integer	required (17-4096)	The vectors' dimensions, fixed once set
`metric`	string	`l2`	`l2` (squared Euclidean) or `cosine`
`bands`	array of 3 integers	chosen by `dims`	Dims coded at 3, 2 and 1 levels
`route`	integer	128 (at most `dims`)	Dims the index routes clusters on
`clusters`	integer	grows with the vectors	A fixed cluster count

curl -s -X POST $SUBSTRIO_URL/v1/_indexes -H "Authorization: Bearer $SUBSTRIO_KEY" \
  -H 'content-type: application/json' \
  -d '{"kind":"vector","collection":"docs","field":"embedding","dims":384,"metric":"cosine"}'

A vector of other dimensions is refused once the index is set.

Vector queries

{"where": {"embedding": {"$knn": {"vector": [0.1, 0.2, 0.3], "k": 10}}}}

{"where": {"embedding": {"$box": {"min": [0.0, 0.0, 0.0], "max": [1.0, 1.0, 1.0]}}}}

$knn returns the k nearest vectors to vector (default k 10) by the field's configured metric. $box matches vectors inside the per-dimension min/max bounds. For a sparse vector field, $sparseKnn takes the same k, with vector as {"indices": [...], "values": [...]}.

Geo queries

{"where": {"location": {"$near": {"lat": 40.7128, "lng": -74.0060, "k": 10}}}}

{"where": {"location": {"$geoWithin": {"$sphere": {"center": {"lat": 40.7128, "lng": -74.0060}, "radius": 5000}}}}}

$near returns the k nearest documents to a lat/lng point. $geoWithin with $box (sw/ne corners) or $sphere (center and radius in meters) matches points inside a region. See query-language.md for the full operator set.

RAG configuration

rag.collection.set (PUT /v1/{collection}/_rag) declares how a collection embeds and searches:

Field	Type	Default	Description
`source_field`	string	required	The text field to embed
`provider.type`	string	required	`openai`, `anthropic`, `ollama`, `groq`, `vllm`, `jina` or `hash`
`provider.model`	string	provider default	The embedding model
`provider.endpoint`	string	provider default	Override the provider's URL
`provider.api_key_ref`	string	none	A secret reference holding the API key
`provider.dimensions`	integer	provider default	Embedding size
`vector_field`	string	`source_field` + `_vector`	Where the embedding is stored
`search_mode`	string	`vector`	`vector`, `sparse` or hybrid
`auto_chunk`	boolean	`false`	Split long text before embedding
`chunk_size`, `chunk_overlap`	integer	provider default	Chunk sizing when `auto_chunk` is on

hash is a deterministic embedding with no semantic meaning: useful for repeatable tests, not for production relevance.

curl -s -X PUT $SUBSTRIO_URL/v1/docs/_rag -H "Authorization: Bearer $SUBSTRIO_KEY" \
  -H 'content-type: application/json' \
  -d '{"source_field":"body","provider":{"type":"openai","model":"text-embedding-3-small"}}'

rag.collection.get (GET /v1/{collection}/_rag) reads the configuration, and rag.collection.delete (DELETE /v1/{collection}/_rag) removes it. rag.get (GET /v1/_rag) reads the app configuration. rag.embed (POST /v1/{collection}/_rag/embed) embeds records without a vector, while rag.reembed (POST /v1/{collection}/_rag/re-embed) embeds every record again after a provider or model change. rag.drift (GET /v1/{collection}/_rag/drift) reports records whose stored embedding no longer matches the current configuration.

RAG search

$search searches the field configured by rag.collection.set. It supports vector, sparse, and hybrid modes; hybrid fuses dense, sparse, and text results:

{"$search": {"query": "refund policy", "mode": "hybrid", "k": 20}}

Field	Type	Default	Description
`query`	string	required	The search text
`mode`	string	`vector`	`vector`/`dense` (embedding only), `sparse` (sparse-only), anything else (hybrid: dense, sparse and text fused)
`k`	integer	`50`	Candidates considered before `limit`/`skip` apply
`decay`	object	none	Scores recent documents higher by a configured field
`strict_model`	boolean	`false`	Only match vectors from the current embedding model
`boost_feedback`	boolean or object	`false`	Re-rank using recorded search feedback

$search can take a bare string ({"$search": "refund policy"}) in place of the object form, and composes with a regular where clause.

ai.cross_search (POST /v1/{collection}/_cross_search) runs one query across several vector fields of the same collection and merges the results, k candidates per field:

curl -s -X POST $SUBSTRIO_URL/v1/docs/_cross_search -H "Authorization: Bearer $SUBSTRIO_KEY" \
  -H 'content-type: application/json' \
  -d '{"query":"refund policy","fields":["title_vector","body_vector"],"k":10}'

search.analytics (GET /v1/{collection}/_analytics/search) reads query volume and result counts for a collection's search traffic.