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

# List Metadata Fields

> Returns the list of all metadata fields (both custom and built-in) for the knowledge base, along with the count of documents using each field.



## OpenAPI

````yaml /en/api-reference/openapi_knowledge.json get /datasets/{dataset_id}/metadata
openapi: 3.0.1
info:
  title: Knowledge API
  description: >-
    API for managing knowledge bases, documents, chunks, metadata, and tags,
    including creation, retrieval, and configuration. **Note:** A single
    Knowledge Base API key has permission to operate on all visible knowledge
    bases under the same account. Please pay attention to data security.
  version: 1.0.0
servers:
  - url: '{apiBaseUrl}'
    description: The base URL for the Knowledge API.
    variables:
      apiBaseUrl:
        default: https://api.dify.ai/v1
        description: Actual base URL of the API
security:
  - ApiKeyAuth: []
tags:
  - name: Knowledge Bases
    description: >-
      Operations for managing knowledge bases, including creation,
      configuration, and retrieval.
  - name: Documents
    description: >-
      Operations for creating, updating, and managing documents within a
      knowledge base.
  - name: Chunks
    description: Operations for managing document chunks and child chunks.
  - name: Metadata
    description: >-
      Operations for managing knowledge base metadata fields and document
      metadata values.
  - name: Tags
    description: Operations for managing knowledge base tags and tag bindings.
  - name: Models
    description: Operations for retrieving available models.
  - name: Knowledge Pipeline
    description: >-
      Operations for managing and running knowledge pipelines, including
      datasource plugins and pipeline execution.
paths:
  /datasets/{dataset_id}/metadata:
    get:
      tags:
        - Metadata
      summary: List Metadata Fields
      description: >-
        Returns the list of all metadata fields (both custom and built-in) for
        the knowledge base, along with the count of documents using each field.
      operationId: listMetadataFields
      parameters:
        - name: dataset_id
          in: path
          required: true
          schema:
            type: string
            format: uuid
          description: Knowledge base ID.
      responses:
        '200':
          description: Metadata fields for the knowledge base.
          content:
            application/json:
              schema:
                type: object
                properties:
                  doc_metadata:
                    type: array
                    description: List of metadata field definitions.
                    items:
                      type: object
                      properties:
                        id:
                          type: string
                          description: Metadata field identifier.
                        name:
                          type: string
                          description: Metadata field name.
                        type:
                          type: string
                          description: Metadata field type.
                        count:
                          type: integer
                          description: Number of documents using this metadata field.
                  built_in_field_enabled:
                    type: boolean
                    description: >-
                      Whether built-in metadata fields are enabled for this
                      knowledge base.
              examples:
                success:
                  summary: Response Example
                  value:
                    doc_metadata:
                      - id: b5c6d7e8-f9a0-1b2c-3d4e-5f6a7b8c9d0e
                        name: author
                        type: string
                        count: 3
                    built_in_field_enabled: true
components:
  securitySchemes:
    ApiKeyAuth:
      type: http
      scheme: bearer
      bearerFormat: API_KEY
      description: >-
        API Key authentication. For all API requests, include your API Key in
        the `Authorization` HTTP Header, prefixed with `Bearer `. Example:
        `Authorization: Bearer {API_KEY}`. **Strongly recommend storing your API
        Key on the server-side, not shared or stored on the client-side, to
        avoid possible API-Key leakage that can lead to serious consequences.**

````