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

# Get a private download URL

> Obtain a short-lived private GET URL for an attachment. preview:true returns an inline image/PDF. Do not log returned URLs.

Read access: a read-enabled personal or team REST API key, or a signed-in user. OAuth clients use the corresponding MCP tool through /mcp.

Obtain a short-lived private GET URL for an attachment. preview:true returns an inline image/PDF. Do not log returned URLs.

URLs expire after five minutes and are private capabilities. preview:true requests inline image/PDF display; otherwise the URL downloads the attachment.

MCP clients can use [`get_attachment_download`](https://www.mill.fyi/mcp-reference/get_attachment_download) for this operation.

[Request conventions](https://www.mill.fyi/api-reference/overview.md) · [API keys](https://www.mill.fyi/api-keys.md) · [MCP connections](https://www.mill.fyi/mcp-connections.md)


## OpenAPI

````yaml api-reference/openapi.json GET /api/tasks/{taskId}/attachments/{attachmentId}/download
openapi: 3.1.0
info:
  title: Mill HTTP API
  version: 1.0.6
  description: >-
    All registered task-board, account, OAuth, MCP transport and health
    operations. MCP tool schemas come from runtime validators; account
    operations follow their server handlers. Example data is fictional.
    Generation imports routes without issuing requests or connecting to a
    database.
servers:
  - url: https://mill-api.example.com
security: []
paths:
  /api/tasks/{taskId}/attachments/{attachmentId}/download:
    get:
      tags:
        - Attachments
      summary: Get a private download URL
      description: >-
        Obtain a short-lived private GET URL for an attachment. preview:true
        returns an inline image/PDF. Do not log returned URLs.


        URLs expire after five minutes and are private capabilities.
        preview:true requests inline image/PDF display; otherwise the URL
        downloads the attachment.


        Read access: a read-enabled personal or team REST API key, or a
        signed-in user. OAuth clients use the corresponding MCP tool through
        /mcp.
      operationId: get_api_tasks_by_taskId_attachments_by_attachmentId_download
      parameters:
        - name: taskId
          in: path
          required: true
          schema:
            type: string
            format: uuid
          description: >-
            The taskId from the corresponding list, record or authorization
            response.
        - name: attachmentId
          in: path
          required: true
          schema:
            type: string
            format: uuid
          description: >-
            The attachmentId from the corresponding list, record or
            authorization response.
        - name: preview
          in: query
          required: false
          schema:
            type: boolean
          description: boolean
      responses:
        '200':
          description: >-
            Successful response. Examples are illustrative; field values vary by
            record.
          content:
            application/json:
              schema:
                type: object
                properties:
                  url:
                    type: string
                  expiresAt:
                    type: string
                additionalProperties: true
                description: >-
                  Illustrative response shape. Fields can be absent in alternate
                  successful flows; see the operation description and example.
              example:
                url: >-
                  https://storage.example.test/private-download?signature=example
                expiresAt: '2027-01-18T09:30:00.000Z'
        default:
          description: >-
            Request failure. Inspect code, message and requestId; respect
            Retry-After on HTTP 429.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
      security:
        - bearerAuth: []
        - sessionCookie: []
components:
  schemas:
    Error:
      type: object
      required:
        - error
      properties:
        error:
          type: object
          required:
            - code
            - message
            - requestId
          properties:
            code:
              type: string
            message:
              type: string
            requestId:
              type: string
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: Personal or team Mill REST API key
    sessionCookie:
      type: apiKey
      in: cookie
      name: mill_session
      description: >-
        Signed-in human browser session; mutation requests also need the exact
        UI Origin

````

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