---
title: "Unlink Measurement"
method: POST
path: "/api/v1/measurements/{measurement_id}/unlink"
tags: ["measurements"]
---

# Unlink Measurement

`POST /api/v1/measurements/{measurement_id}/unlink`

## Request

- Base URL: `https://api.rudus.ai` (the document declares no server; this is the origin it was published from)
- URL: `https://api.rudus.ai/api/v1/measurements/{measurement_id}/unlink`
- Auth: none declared
- TypeScript: <https://skmtc.dev/rudus/apis/rudus-api/docs/api/v1/measurements/:measurement_id/unlink/post.ts> (a function with typed inputs; its response is checked against the schema)

Fork one member out of its link group, keeping its current geometry as a
private copy.

Returns every row whose membership changed, so the client can reconcile the
remainder too — unlinking from a two-member group dissolves the other member
as well (spec §7.3). 409 if the measurement is not in a group.

## Path parameters

- `measurement_id` string, uuid, required

## Response `200`

Successful Response

- MeasurementListEnvelope: Every measurement PATCH returns this: one item for an ordinary measurement, N in member id order for a link group (RUD-263 spec §7.1). One stable envelope rather than two shapes — pre-launch, the clean break beats a compat shim that every future caller would have to remember.
  - `items` Measurement[], required
    - `id` string, uuid, required
    - `condition_id` string, uuid, required
    - `page_id` string, uuid, required
    - `scale_region_id` string, uuid, nullable
    - `geometry` union, required
      - PointGeometryOutput
        - `type` 'point', required
        - `x` string, required
        - `y` string, required
        - `rotation` string, nullable
      - PolylineGeometryOutput
        - `type` 'polyline', required
        - `points` array[], required
          - unknown[]
            - unknown
        - `bulges` string[], nullable
      - PolygonGeometryOutput
        - `type` 'polygon', required
        - `points` array[], required
          - unknown[]
            - unknown
        - `holes` array[], nullable
          - array[]
            - unknown[]
              - …
        - `grid` GridAlignmentOutput: Rebar-grid pose for an area measurement (spec 2026-07-13 §5.2). Stored inside geometry JSONB — additive, no DDL (ADR-0097 precedent). angle_deg is CCW-positive PDF user-space, normalized to [0, 180): a line family has 180° symmetry, unlike marker glyphs' [0, 360). New normalizer — borrows only the round-then-normalize technique from ADR-0097.
          - `origin` unknown[], required
            - unknown
          - `angle_deg` string
    - `name` string, nullable
    - `computed_value` string, nullable, required
    - `computed_derivations` DerivationValue[]
      - `ordinal` integer, required
      - `result_type` 'count' | 'total_height' | 'perimeter' | 'surface_area_top_or_bottom' | 'surface_area_top_and_bottom' | 'surface_area_all_sides' | 'surface_area_full' | 'volume' | 'length' | 'segment_count' | 'surface_area_single_side' | 'surface_area_both_sides' | 'surface_area_single_end' | 'surface_area_both_ends' | 'surface_area_all_side_duct' | 'area' | 'grid_length_visible' | 'grid_length_x_visible' | 'grid_length_y_visible' | 'grid_intersection_count' | 'tile_count_average' | 'tile_count_visible' | 'area_counts', required
      - `uom` 'EA' | 'LF' | 'IN' | 'FT' | 'SF' | 'SY' | 'CF' | 'CY', required
      - `value` number, required
    - `effective_multiplier` string
    - `extension_values` object
    - `bid_area_id` string, uuid, nullable
    - `ambiguous` boolean
    - `link_group_id` string, uuid, nullable
    - `created_at` string, date-time, required

## Other responses

- `4XX`: Client Error
- `5XX`: Server Error

---

[API](https://skmtc.dev/rudus/apis/rudus-api.md) - [All operations](https://skmtc.dev/rudus/apis/rudus-api/llms.txt) - [OpenAPI document](https://skmtc.dev/rudus/apis/rudus-api/revisions/5673f72c8a5d?raw)