# Presigned R2 GET for a file

`POST /v1/datasets/download/presign`

**Deprecated.**

Deprecated: only SDKs before 0.6.9 call this, and it is removed at the
date in its `Sunset` header. Use
`POST /v1/datasets/download/presign-exact-batch`, which plans a whole page
of files of one immutable snapshot, as the current SDK does.

Presigned GET plan for one file. The file_id MUST belong to the caller's
own org — qds-api's tenant-scope gate 404s a foreign file_id, so a customer
can't presign another account's chunks by guessing one (no tree pre-fetch).

- Base URL: `https://junction-api.qualiastudios.dev`
- Authentication: an API key in the `X-API-Key` header, or `Authorization: Bearer …`

## Request body

Required: `application/json` `DownloadPresignBody`

## Responses

- `200` Successful Response: `application/json` `any`
- `401` Invalid or missing API key: `application/json` `ErrorResponse`
- `422` Validation Error: `application/json` `HTTPValidationError`

## Schemas

```yaml
DownloadPresignBody:
  properties:
    name:
      type: string
    file_id:
      type: string
    ttl_seconds:
      type: integer
      default: 300
  type: object
  required:
    - name
    - file_id
  title: DownloadPresignBody
ErrorResponse:
  properties:
    detail:
      type: string
      description: Error message describing what went wrong
  type: object
  required:
    - detail
  title: ErrorResponse
  description: Standard error response.
HTTPValidationError:
  properties:
    detail:
      items:
        $ref: "#/components/schemas/ValidationError"
      type: array
  type: object
  title: HTTPValidationError
ValidationError:
  properties:
    loc:
      items:
        type:
          - string
          - integer
      type: array
      title: Location
    msg:
      type: string
      title: Message
    type:
      type: string
      title: Error Type
    input: {}
    ctx:
      type: object
      title: Context
  type: object
  required:
    - loc
    - msg
    - type
  title: ValidationError
```