Attach uploaded files to a customer

POST/v1/api/store/{team_slug}/customer/{hash_id}/media/attach

v1Operation ID v1_public_customer_upload_multiple_files

Attaches files you already uploaded to the customer, and returns them.

Upload each file first with Upload a file; then send its id here with the collection it belongs in. A file can be attached once: after that it belongs to the customer.

Permission

Needs the Manage Customers permission (either level). Whether the customer is assigned to you is not checked.

Business rules

• Each id must be a file uploaded with Upload a file and not attached to anything yet; an attached file fails the whole request.
• Customers synced from Shopify are read-only here: changes are refused with 422 validation_error "External customers are read-only. Manage changes from Shopify." System customers (is_system: true) are refused the same way ("System customer cannot be modified or deleted.").

Side effects

• Moves each upload onto the customer and builds its previews.

Path parameters

• team_slugstringrequired

  Your team slug, shown as Team ID next to your API key in Profile.

  • Example your-team
• hash_idstringrequired

  The customer's id (id from List customers or Create a customer). A hash id from an earlier answer; unique keys and document numbers (such as PO0042) don't work here.

  • Example EDhVUaC6jbLbed

Request body

application/json, required.

• attachmentarray of objectsrequired
  • At least 1 item
  Fields of each item (3)

  • idstringrequired

    The uploaded file's id.

  • collectionstring | null

    Where the file goes. Defaults to external_file, which the customer can see.

    • One of: "tax_exemption", "internal_file", "external_file"
  • file_namestring | null

    A display name. Defaults to the uploaded file name.

    • At most 255 characters

Response

200Successful response.

• dataarray of objectsrequired
  Fields of each item (18)

  • collectionstringrequired

    Customer files: tax_exemption, internal_file or external_file. Vendor files: default, mockup or production_file.

  • created_atstring (date-time)required
  • file_namestringrequired
  • idstringrequired
  • mime_typestring | nullrequired
  • namestring | nullrequired

    The display name.

  • sizeintegerrequired

    Bytes.

  • custom_propertiesobject | array
  • customer_idstring

    Customer files only.

  • dimensionsobject | null

    Pixel size of an image, read from its header; null for other files and for images uploaded before the size was recorded.

    Child fields (2)

    • heightinteger
    • widthinteger
  • is_imageboolean
  • positioninteger | null

    Where the file sorts.

  • previewobject | null

    Preview image links small, medium and large (250, 800 and 1200 px), or null when there is no preview.

  • preview_statestring

    ready: the preview links work. processing: an image over 10 MB whose stored preview a worker is still making (seconds); read the file again, or in the web app wait for media.preview_state_changed on the team channel. too_large: an image over 120 megapixels; it never gets a preview. failed: the worker gave up. none: not an image.

    • One of: "ready", "processing", "too_large", "failed", "none"
  • show_in_pdfboolean | null
  • source_media_idstring | null
  • urlstring | null

    Where to download the file.

  • view_urlstring | null

    A signed link to view the file. It expires: read it fresh, and don't store it.

• statusintegerrequired
• successbooleanrequired

Errors

• 401The API key is missing or wrong (unauthenticated).

• 403You are not allowed to do this. api_access_not_in_plan: your team's plan doesn't include API access (Pro and above, with an active subscription or trial), so every request answers this until the team upgrades. When your role lacks the permission the operation needs, the body is only {"message": "Insufficient Permission"}. Other refusals use the error envelope, with unauthorized or user_is_not_authorized.

  When

  Your role has no Manage Customers permission. This 403 has a short body, {"message": "Insufficient Permission"}, with no success or error.

  Fix

  Ask a team owner to give your role Manage Customers.

• 404Not found. page_not_found: the team slug is unknown, you are not a member of the team, or an id in the path is not one of this team's. code: null, with a message that starts "No query results for": there is no record with that id.

  When

  An upload id does not exist, or no live customer has this id. error.code is null and error.message names the record type.

  Fix

  Upload the file first, or check the customer id.

• 422The request was refused and changed nothing. validation_failed lists what to fix in error.fields; other codes name a business rule, explained in error.message. A few checks answer with only {"message": "..."}. An operation that calls another service (a payment provider, a carrier, an accounting app) can answer connect_timeout ("Please retry again") when that service does not answer in time: the change may or may not have happened there, so read the record back before you retry.

  When

  attachment is empty, an id is missing or not a valid id, a collection is not allowed, or a file_name is over 255 characters. error.code is validation_failed.

  Fix

  Send at least one file and a valid collection.

  When

  The customer comes from Shopify, or is a system customer (error.code validation_error, with the reason in error.message).

  Fix

  Change Shopify customers in Shopify. System customers cannot be changed.

• 500A business rule refused the request (see the operation's errors), or something failed inside YoPrint. Refusals use the error envelope with a code such as action_not_allowed; an unexpected failure answers {"message": "Server Error"}. Repeating a refusal gets the same answer; after an unexpected failure, read the record back before you retry a change.

  When

  An upload is already attached to something else. Nothing is attached.

  Fix

  Upload the file again and send the new id.

Related

• POSTUpload a file/v1/api/store/{team_slug}/async_upload
• GETList a customer's files/v1/api/store/{team_slug}/customer/{hash_id}/media

Example request

curl

curl -X POST 'https://secure.yoprint.com/v1/api/store/your-team/customer/EDhVUaC6jbLbed/media/attach' \  -H 'Authorization: Bearer YOUR_API_KEY' \  -H 'Accept: application/json' \  -H 'X-Yoprint-Decimal-Format: exact-v1' \  -H 'Content-Type: application/json' \  -d '{    "attachment": [      {        "collection": "tax_exemption",        "file_name": "Resale certificate 2026.pdf",        "id": "4GR9C3ZTMYtda5"      }    ]  }'

Example response 200

Response

{
  "data": [
    {
      "collection": "tax_exemption",
      "created_at": "2026-11-01T09:00:00+00:00",
      "custom_properties": [],
      "customer_id": "V4keXwwxMQyXw7",
      "file_name": "resale-certificate.pdf",
      "id": "4GR9C3ZTMYtda5",
      "is_image": false,
      "mime_type": "application/pdf",
      "name": "Resale certificate 2026.pdf",
      "position": 0,
      "preview": null,
      "show_in_pdf": null,
      "size": 48211,
      "source_media_id": null,
      "url": "https://example.com/media/4GR9C3ZTMYtda5/download",
      "view_url": "https://example.com/media/4GR9C3ZTMYtda5/view"
    }
  ],
  "status": 200,
  "success": true
}