---
title: "Get a declared metadata column"
method: GET
path: "/metadata_columns/{key}"
tags: ["metadata-columns"]
---

# Get a declared metadata column

`GET /metadata_columns/{key}`

(reserved for future use) Returns a single declared metadata column.

Required scope: \`knowledge:write\`

## Response `200`

Metadata column

- MetadataColumn — A declared metadata column materialized as a typed LanceDB column.
  - `key` string, required — Metadata key name (also the LanceDB column source name).
  - `type` 'string' | 'integer', required — Column type. Only string / integer (scalar-indexable) are allowed.
  - `filter_only` boolean — When true, the value is kept only as a LanceDB column for filtering and is not included in chunk bodies or API responses.
  - `index_type` 'btree' | 'bitmap' — Scalar index type actually applied to the column. Defaults to BTREE for integer and BITMAP for string when not specified at creation; override for cardinality (e.g. high-cardinality string -> btree).
  - `created_at` string, nullable

## Other responses

- `401` — Unauthorized - Authentication failed
- `403` — Forbidden - the API key is missing the scope required by this endpoint
- `404` — Not found

## Changes

> 71 revisions in range; 18 not diffed.

- **2026-06-17** `05add33422b2` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/qlonolink/apis/qaip-apis/changes/metadata_columns/:key/get.md)

---

[API](https://skmtc.dev/qlonolink/apis/qaip-apis.md) · [All operations](https://skmtc.dev/qlonolink/apis/qaip-apis/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/qlonolink/qaip-apis/revisions/61dc40676905/schema)