Downloads a supporting document attachment by ID. Returns the file bytes stored when the attachment was uploaded on create or update.
This endpoint is separate from Download Sale Invoice PDF (/download-pdf), which returns the rendered invoice PDF only.
| Parameter | Type | Required | Description |
|---|---|---|---|
id | string | Required | The UUID of the sales invoice. |
attachmentId | string | Required | The attachment id from the document response attachments array. |
Status code: 200 OK
Response headers:
| Header | Description |
|---|---|
Content-Type | Stored MIME type of the attachment (e.g. application/pdf). |
Content-Disposition | attachment; filename="..." using the stored file name. |
X-Suggested-Filename | Suggested file name for clients that prefer a dedicated header. |
Response body: Raw file bytes (not JSON).
| Status | Description |
|---|---|
| 401 Unauthorized | Authentication required or invalid token. |
| 404 Not Found | Invoice or attachment not found. |
| 500 Internal Server Error | An error occurred while processing the request. |
