> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ionworks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# List the JSON metadata fields measurements in a scope carry

> List metadata leaves usable as `meta` filters on the matching list endpoint.

Pass exactly one scope. The project scope covers measurement, instance and
spec metadata; the spec scope measurement and instance metadata; the
instance scope measurement metadata only.



## OpenAPI

````yaml https://api.ionworks.com/openapi.json get /cell_measurements/metadata_fields
openapi: 3.1.0
info:
  title: FastAPI
  version: 0.1.0
servers:
  - url: https://api.ionworks.com
    description: Production
security: []
paths:
  /cell_measurements/metadata_fields:
    get:
      tags:
        - Cell Measurements
      summary: List the JSON metadata fields measurements in a scope carry
      description: >-
        List metadata leaves usable as `meta` filters on the matching list
        endpoint.


        Pass exactly one scope. The project scope covers measurement, instance
        and

        spec metadata; the spec scope measurement and instance metadata; the

        instance scope measurement metadata only.
      operationId: list_measurement_metadata_fields_cell_measurements_metadata_fields_get
      parameters:
        - name: project_id
          in: query
          required: false
          schema:
            anyOf:
              - type: string
                format: uuid
              - type: 'null'
            title: Project Id
        - name: cell_specification_id
          in: query
          required: false
          schema:
            anyOf:
              - type: string
                format: uuid
              - type: 'null'
            title: Cell Specification Id
        - name: cell_instance_id
          in: query
          required: false
          schema:
            anyOf:
              - type: string
                format: uuid
              - type: 'null'
            title: Cell Instance Id
      responses:
        '200':
          description: Successful Response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MeasurementMetadataFieldsResponse'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    MeasurementMetadataFieldsResponse:
      properties:
        fields:
          items:
            $ref: '#/components/schemas/MeasurementMetadataField'
          type: array
          title: Fields
      type: object
      required:
        - fields
      title: MeasurementMetadataFieldsResponse
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
    MeasurementMetadataField:
      properties:
        source:
          type: string
          title: Source
          description: >-
            Which JSON it lives in, e.g. `test_setup`, `instance`, `spec_anode`.
            Used verbatim as the `<source>` of a `meta` filter.
        path:
          type: string
          title: Path
          description: Dot-separated key path, e.g. `anode.loading`.
        kind:
          type: string
          enum:
            - number
            - text
          title: Kind
        quantity:
          type: boolean
          title: Quantity
          description: >-
            True when the leaf is a `{value, unit}` object; filter on
            `<path>.value` then.
        unit:
          anyOf:
            - type: string
            - type: 'null'
          title: Unit
          description: Most common unit across rows, for Quantities.
        mixed_units:
          type: boolean
          title: Mixed Units
          description: Rows disagree on the unit; values are not converted.
          default: false
        count:
          type: integer
          title: Count
          description: Number of measurements in scope carrying it.
        min:
          anyOf:
            - type: number
            - type: 'null'
          title: Min
          description: Smallest value, for number fields.
        max:
          anyOf:
            - type: number
            - type: 'null'
          title: Max
          description: Largest value, for number fields.
        decimals:
          anyOf:
            - type: integer
            - type: 'null'
          title: Decimals
          description: Fractional digits to display, the most any value stores (max 4).
        histogram:
          anyOf:
            - items:
                type: integer
              type: array
            - type: 'null'
          title: Histogram
          description: Counts in equal-width bars from `min` to `max`, for number fields.
      type: object
      required:
        - source
        - path
        - kind
        - quantity
        - count
      title: MeasurementMetadataField
      description: >-
        One JSON leaf that the measurement tables can show and filter as a
        column.
    ValidationError:
      properties:
        loc:
          items:
            anyOf:
              - type: string
              - type: integer
          type: array
          title: Location
        msg:
          type: string
          title: Message
        type:
          type: string
          title: Error Type
        input:
          title: Input
        ctx:
          type: object
          title: Context
      type: object
      required:
        - loc
        - msg
        - type
      title: ValidationError

````

This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.