> ## Documentation Index > Fetch the complete documentation index at: https://dify-6c0370d8-fix-template-upload-size-guidance.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Update Metadata Field > Rename a custom metadata field. ## OpenAPI ````yaml /en/api-reference/openapi_service.json patch /datasets/{dataset_id}/metadata/{metadata_id} openapi: 3.0.1 info: 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. title: Dify Service API version: 1.0.0 servers: - description: >- Base URL of the Dify Service API. For self-hosted deployments, replace it with your own API base URL. url: https://{api_base_url} variables: api_base_url: default: api.dify.ai/v1 description: Host and path of the API base URL, without the `https://` prefix. security: - ApiKeyAuth: [] tags: - description: Operations related to chat messages and interactions. name: Chat Messages - description: File upload and preview operations. name: Files - description: Operations related to end user information. name: End Users - description: User feedback operations. name: Feedback - description: Operations related to managing conversations. name: Conversations - description: Text-to-Speech and Speech-to-Text operations. name: Audio - description: Operations to retrieve application settings and information. name: Applications - description: Operations related to managing annotations for direct replies. name: Annotations - description: Endpoints for resuming paused workflows that require human input. name: Human Input - description: Operations for executing and managing workflows. name: Workflow Runs - description: Operations related to text generation and completion. name: Completion Messages - description: >- Operations for managing knowledge bases, including creation, configuration, and retrieval. name: Knowledge Bases - description: >- Operations for creating, updating, and managing documents within a knowledge base. name: Documents - description: Operations for managing document chunks and child chunks. name: Chunks - description: >- Operations for managing knowledge base metadata fields and document metadata values. name: Metadata - description: Operations for managing knowledge base tags and tag bindings. name: Tags - description: Operations for retrieving available models. name: Models - description: >- Operations for managing and running knowledge pipelines, including datasource plugins and pipeline execution. name: Knowledge Pipeline paths: /datasets/{dataset_id}/metadata/{metadata_id}: patch: tags: - Metadata summary: Update Metadata Field description: Rename a custom metadata field. operationId: updateMetadataField parameters: - description: >- Knowledge base ID. See [List Knowledge Bases](/en/api-reference/knowledge-bases/list-knowledge-bases). in: path name: dataset_id required: true schema: format: uuid type: string - description: >- ID of the metadata field to rename. See [List Metadata Fields](/en/api-reference/metadata/list-metadata-fields). in: path name: metadata_id required: true schema: format: uuid type: string requestBody: content: application/json: schema: properties: name: description: >- New name for the field. Must be unique among the knowledge base's fields and at most 255 characters. type: string required: - name type: object required: true responses: '200': content: application/json: examples: success: summary: Response Example value: id: b5c6d7e8-f9a0-1b2c-3d4e-5f6a7b8c9d0e name: author type: string schema: properties: id: description: Metadata field identifier. type: string name: description: Metadata field name. type: string type: description: Metadata field type. type: string type: object description: Metadata field updated successfully. '400': content: application/json: examples: invalid_param: summary: invalid_param value: code: invalid_param message: Metadata name already exists. status: 400 description: >- `invalid_param` : The metadata name already exists, exceeds 255 characters, or conflicts with a built-in field. '403': content: application/json: examples: forbidden_1: summary: forbidden (api access) value: code: forbidden message: Dataset api access is not enabled. status: 403 forbidden_2: summary: forbidden (rate limit) value: code: forbidden message: >- Sorry, you have reached the knowledge base request rate limit of your subscription. status: 403 description: >- - `forbidden` : Dataset api access is not enabled. - `forbidden` : Sorry, you have reached the knowledge base request rate limit of your subscription. '404': content: application/json: examples: not_found: summary: not_found value: code: not_found message: Dataset not found. status: 404 description: '`not_found` : Dataset not found.' components: securitySchemes: ApiKeyAuth: 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/api-reference/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`). scheme: bearer type: http ````