Find nearest vectors

Returns the k stored vectors nearest to a query vector, optionally filtered by metadata.

POST /v1/tenants/{tenant}/vector/{table}/topk

Find embeddings nearest to a queryScores depend on the distance metric; k is a result limit.

Prepare a compatible query vectorMatch the stored embeddings' dimension and metric.
Search with optional filtersLimit candidates to the metadata you need.
Read IDs and scoresUse each ID to retrieve the source data.

Before you start

Use your database bearer token.

Store dense vectors in the collection before searching it. The example uses demo_vectors; scores depend on your data and distance metric.

Path parameters

Field	Type	Required
`tenant`	`string`	Required
`table`	`string`	Required

Headers

Field	Type	Required	Description
`x-oc-db-user`	`string`	Optional	Acting database user (role, grant and row-policy checks). Send with x-oc-db-key.
`x-oc-db-key`	`string`	Optional	API key of the x-oc-db-user user.

Request body

application/json

Limits and accepted values

The query vector field is `query` (not `vector`).
mode: fast | high_recall (default);
index: hnsw (default) | ivf | ivf_pq;
nprobe (1-256) applies to ivf / ivf_pq;
refine_k_factor (1-64) applies to ivf_pq with raw vectors kept;
engine "bruteforce" forces an exact scan.
k above the server ceiling (default 4096) is a 400.
`filter` is a strict-equality metadata map ({field: value});
`filter_expr` is the typed operator filter (e.g. {"tag": {"$eq": "a"}}) and cannot be combined with a non-empty `filter`;
`require_complete: true` turns an underfilled filtered answer into a 422.

Field	Type	Required
`dim`	`integer`	Required
`embedder`	`string`	Optional
`filter`	`object`	Optional
`filter_expr`	`object`	Optional
`index`	`string`	Optional
`k`	`integer`	Required
`metric`	`string`	Optional
`mode`	`string`	Optional
`nprobe`	`integer`	Optional
`query`	`number[]`	Required

Fields in query

Field	Type	Required
`query`	`number`	Optional

Field	Type	Required
`refine_k_factor`	`integer`	Optional
`require_complete`	`boolean`	Optional

Each hit contains a vector ID and score. Interpret the score using the requested metric and use the ID to retrieve source data. A requested k is a limit, not a guarantee that enough matching records exist.

Response statuses

HTTP status reference

Status	What to do
200	OK
400	Correct the request before retrying.
401	Check the credential and Authorization header.
402	Check feature access or available credits.
403	Check tenant access, roles and permissions.
408	Reduce query work or adjust the timeout.
409	Resolve the conflict before retrying.
413	Split or reduce the request body.
415	Send the required Content-Type.
422	Correct the values or unsupported combination.
429	Honor Retry-After when present; back off.
499	The client cancelled the request.
500	Check the outcome before retrying a write.
501	Check deployment support for this operation.
503	Honor Retry-After when present; check write outcomes.

Request example

curl --include --request POST "${OC_BASE_URL}/v1/tenants/${OC_TENANT}/vector/demo_vectors/topk" \
  --header "Authorization: Bearer ${OC_TOKEN}" \
  --header "Content-Type: application/json" \
  --data-binary '{
  "query": [
    0.1,
    0.2,
    0.3
  ],
  "dim": 3,
  "metric": "cosine",
  "k": 5
}'

Response example

Examples use synthetic values to show the response format.

Response status

[
  {
    "id": "v1",
    "score": 1
  }
]

Illustrates a collection with only the quickstart vector v1; scores depend on your data.

Download the OpenAPI specification for the complete response schemas.

Before you startCopy Anchor Link

Path parametersCopy Anchor Link

HeadersCopy Anchor Link

Request bodyCopy Anchor Link

Read the resultCopy Anchor Link

Response statusesCopy Anchor Link

Before you start

Path parameters

Headers

Request body

Read the result

Response statuses