> ## 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. # Download File > **Available for**: Workflow, Chatflow Serves a file's raw bytes for preview or download. The file must belong to the calling app, the environment, and the `user`. **Standard API equivalent**: [Download File](/en/3.13.x/develop/api/files/download-file). Differences: - A `kind` parameter selects the file source. - `user` is required. - Error codes differ. ## OpenAPI ````yaml /en/3.13.x/develop/api/openapi_service.json get /v2/files/{file_id}/preview 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. - name: Deployed Environments description: >- Endpoints served by deployed environments over the `v2` base URL. Deployed environments serve only the endpoints in this group; calling any other path there returns `404 not_found`. Authentication and errors differ from the standard Service API; each page here is authoritative for deployed environments. paths: /v2/files/{file_id}/preview: get: tags: - Deployed Environments summary: Download File description: >- **Available for**: Workflow, Chatflow Serves a file's raw bytes for preview or download. The file must belong to the calling app, the environment, and the `user`. **Standard API equivalent**: [Download File](/en/3.13.x/develop/api/files/download-file). Differences: - A `kind` parameter selects the file source. - `user` is required. - Error codes differ. operationId: downloadDeployedFile parameters: - name: file_id in: path required: true description: >- ID of the file to download. Two sources: the `id` returned by [Upload File](/en/3.13.x/develop/api/deployed-environments/upload-file), and the `upload_file_id` of an entry in a message's `message_files` from [List Conversation Messages](/en/3.13.x/develop/api/deployed-environments/list-conversation-messages). Tool-produced files need `kind=tool`. schema: type: string format: uuid - name: user in: query required: true description: >- End-user identifier, defined by your app and unique within it. Must match the `user` that owns the file. See [End User Identity](/en/3.13.x/develop/api/guides/end-user-identity). schema: type: string minLength: 1 maxLength: 255 - name: as_attachment in: query required: false description: >- When `true`, the file downloads as an attachment instead of rendering inline in the browser. schema: type: boolean default: false - name: kind in: query required: false description: >- File source. URLs returned in message payloads already carry the right value; set it manually only when constructing URLs yourself. schema: type: string enum: - upload - tool default: upload responses: '200': description: >- The raw file content. `Content-Type` is the file's own MIME type. When `as_attachment` is `true`, the response is sent as `application/octet-stream` with `Content-Disposition: attachment`. HTML files always download, whatever `as_attachment` says. content: application/octet-stream: schema: type: string format: binary '400': description: >- - `invalid_param`: `user`, `kind`, or `as_attachment` is not valid. The message is `invalid argument`. - `invalid_param`: `file_id` is not a UUID. The message is `invalid id`. - `app_unavailable`: the app can't serve API requests in this environment right now. - API access is turned off. - The app is not deployed here. - A deployment is still rolling out. - The environment is being deleted. Ask the app's owner to check its **Access Point** tab, or an administrator to check the environment in the Enterprise Dashboard, and retry once it serves again. content: application/json: examples: invalid_param: summary: invalid_param value: code: invalid_param message: invalid argument status: 400 invalid_param_id: summary: invalid_param (invalid id) value: code: invalid_param message: invalid id status: 400 app_unavailable: summary: app_unavailable value: status: 400 code: app_unavailable message: App unavailable, please check your app configurations. '401': description: >- `unauthorized`: the API key is missing, malformed, unknown, or revoked. content: application/json: examples: unauthorized: summary: unauthorized value: code: unauthorized message: Access token is invalid status: 401 '404': description: >- - `file_not_found`: the file does not exist, or it does not belong to the calling app, environment, `user`, and `kind`. - `APPDEPLOY_APP_NOT_FOUND`: Dify has no record of the app this API key belongs to. Check that the app still exists. Message `app not found`. content: application/json: examples: file_not_found: summary: file_not_found value: status: 404 code: file_not_found message: The requested file was not found. app_not_found: summary: APPDEPLOY_APP_NOT_FOUND value: code: APPDEPLOY_APP_NOT_FOUND message: app not found status: 404 '500': description: >- `internal_server_error`: the platform could not complete the request; retry, and contact your administrator if it persists. content: application/json: examples: internal_server_error: summary: internal_server_error value: code: internal_server_error message: internal error status: 500 '503': description: >- `internal_server_error`: the file service is temporarily unavailable; retry, and contact your administrator if it persists. content: application/json: examples: internal_server_error: summary: internal_server_error value: code: internal_server_error message: file service unavailable status: 503 servers: - url: https://{deployed_api_base_url} description: >- Base URL shared by every deployed environment: the standard Service API address, with `/v2` in place of `/v1`. variables: deployed_api_base_url: default: api.example.com description: >- On the app's **Access Point** tab, copy the full URL from any deployed environment's **Backend Service API** card, then remove the `https://` prefix and the trailing `/v2`. 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/3.13.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`). ````