> ## Documentation Index > Fetch the complete documentation index at: https://enterprise-docs.dify.ai/llms.txt > Use this file to discover all available pages before exploring further. # Update Document Metadata in Batch > Update metadata values for multiple documents in a single request. ## OpenAPI ````yaml /en/3.11.x/develop/api/openapi_service.json post /datasets/{dataset_id}/documents/metadata openapi: 3.0.1 info: title: Dify Service API description: >- REST API for Dify applications and knowledge bases. Application endpoints authenticate with an app API key; knowledge endpoints authenticate with a dataset API key. version: 1.0.0 servers: - url: https://{api_base_url} description: >- Base URL of the Dify Service API. Replace it with your deployment's API endpoint. variables: api_base_url: default: api.example.com/v1 description: Host and path of the API base URL, without the `https://` prefix. security: - ApiKeyAuth: [] tags: - name: Chat Messages description: Operations related to chat messages and interactions. - name: Files description: File upload and preview operations. - name: End Users description: Operations related to end user information. - name: Feedback description: User feedback operations. - name: Conversations description: Operations related to managing conversations. - name: Audio description: Text-to-Speech and Speech-to-Text operations. - name: Applications description: Operations to retrieve application settings and information. - name: Annotations description: Operations related to managing annotations for direct replies. - name: Human Input description: Endpoints for resuming paused workflows that require human input. - name: Workflow Runs description: Operations for executing and managing workflows. - name: Completion Messages description: Operations related to text generation and completion. - 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}/documents/metadata: post: tags: - Metadata summary: Update Document Metadata in Batch description: Update metadata values for multiple documents in a single request. operationId: batchUpdateDocumentMetadata parameters: - name: dataset_id in: path required: true schema: type: string format: uuid description: >- Knowledge base ID. See [List Knowledge Bases](/en/3.11.x/develop/api/knowledge-bases/list-knowledge-bases). requestBody: required: true content: application/json: schema: type: object required: - operation_data properties: operation_data: type: array items: type: object required: - document_id - metadata_list properties: document_id: type: string description: >- ID of the document to update. See [List Documents](/en/3.11.x/develop/api/documents/list-documents). metadata_list: type: array items: type: object required: - id - name properties: id: type: string description: >- Metadata field ID. See [List Metadata Fields](/en/3.11.x/develop/api/metadata/list-metadata-fields). name: type: string description: Metadata field name. value: description: >- Metadata value. Can be a string, number, or `null`. description: Metadata fields to set on the document. partial_update: type: boolean default: false description: >- Whether to partially update metadata, keeping existing values for unspecified fields. description: Document metadata update operations, one entry per document. responses: '200': description: Document metadata updated successfully. content: application/json: schema: type: object properties: result: type: string description: Operation result. examples: success: summary: Response Example value: result: success '400': description: >- `invalid_param` : A referenced document was not found, or another metadata operation is already running for a document in this request. content: application/json: examples: invalid_param_doc: summary: invalid_param (document) value: status: 400 code: invalid_param message: Document not found. '403': description: '- `forbidden` : Dataset api access is not enabled.' content: application/json: examples: forbidden: summary: forbidden (api access) value: status: 403 code: forbidden message: Dataset api access is not enabled. '404': description: '`not_found` : Dataset not found.' content: application/json: examples: not_found: summary: not_found value: status: 404 code: not_found message: Dataset not found. components: securitySchemes: ApiKeyAuth: type: http scheme: bearer bearerFormat: API_KEY description: >- Every request authenticates with an API key: `Authorization: Bearer {API_KEY}`. App endpoints take an app API key; knowledge endpoints take a knowledge base API key ([Get Started](/en/3.11.x/develop/api/guides/get-started)). Keep keys server-side; never embed them in client code. Requests with a missing or invalid key fail with HTTP `401` (`unauthorized`). ````