Prepare uploaded campaign images for review in Box

Define the review rendition and source of truth

Decide whether the upload is an editable master, a flattened export, or only a review candidate. This workflow creates a bounded JPEG for consistent preview and discussion; it does not preserve layers, transparency, every color characteristic, or the editability of the source. Keep the master in the system chosen by the creative team when those properties matter.

Create a campaign review record before processing. It should identify the campaign, source version, uploader, intended rendition policy, workflow version, and current approval state. A file appearing in Box is not by itself evidence that the correct campaign received it or that a reviewer approved it.

Build the JPEG-to-Box review Template

The Template receives one artwork upload, creates a JPEG derivative that fits within the chosen review dimensions, and stores only that derivative in Box. zoom is false so a small source is not enlarged, and strip removes embedded metadata from the review copy. The campaign-specific path also includes Assembly uniqueness to avoid collisions between repeated filenames.

Keep allow_steps_override false. Let the browser send only the file and a bounded campaign_id that the server has already authorized. The client must not choose the Box credential, folder root, sharing behavior, dimensions, or format. Template upload limits complement the application’s own type, tenant, quota, and campaign-state checks.

{
  "allow_steps_override": false,
  "auth": {
    "max_number_of_files": 1,
    "max_size": 104857600
  },
  "steps": {
    ":original": {
      "robot": "/upload/handle"
    },
    "review_jpeg": {
      "use": ":original",
      "robot": "/image/resize",
      "width": 2000,
      "height": 2000,
      "resize_strategy": "fit",
      "zoom": false,
      "format": "jpg",
      "quality": 88,
      "strip": true
    },
    "box_review": {
      "use": "review_jpeg",
      "robot": "/box/store",
      "credentials": "box-campaign-review",
      "path": "campaigns/${fields.campaign_id}/review/${assembly.id}/${file.url_name}",
      "create_sharing_link": false,
      "result": true
    }
  }
}

Prepare Box access before running production work

Box Template Credentials use a Platform App configured for Server Authentication with JWT. Store the downloaded JSON key configuration in the credential rather than source control, browser code, or Assembly Instructions. A Box administrator or co-administrator must authorize the app before it can operate.

The JWT identity is the app’s Service Account. /box/store walks the configured path from that account’s root and creates missing folder segments. For the sample, make the intended campaigns root available to the Service Account through Box collaboration, verify its folder ID and the campaign child’s identity, and grant the permissions needed to create the review subfolders and upload files. Sharing only a nested campaign folder does not make the sample’s full campaigns path resolve from the Service Account’s root. A missing path can create a separate private folder tree instead of failing, so verify the destination and collaborator access before notifying reviewers.

If the app configuration or scopes change, coordinate reauthorization and test a known folder before resuming unattended work. A valid JWT does not guarantee access to every enterprise folder.

Keep export, collaboration, and publication separate

Set create_sharing_link to false. Box collaboration membership, enterprise policy, and application authorization should determine who reviews the file. Enabling the flag makes /box/store explicitly request an open shared link, intended for anyone holding the URL, subject to Box policy. The Robot replaces the result URL with that link; it does not request a collaborators-only link.

If a campaign later needs a shared link, create it as a separate authorized action with an explicit access level, audience, expiry, and revocation owner. Verify the effective access under the enterprise’s Box policy before distributing the link.

Review fidelity and identity before approval

Test transparent PNGs, CMYK or profile-bearing images, text-heavy artwork, gradients, fine lines, orientation metadata, very large dimensions, and unusually small sources. Compare the JPEG against the source at realistic review sizes. A technically valid conversion may still introduce unacceptable color, transparency, or compression changes.

After export, persist the Assembly ID and expected destination path with the campaign review record. /box/store does not return the uploaded Box file ID; with create_sharing_link false, the result keeps the input file’s Transloadit identity and URL. Resolve the destination folders and exact filename through the Box API’s folder-items endpoint, following pagination, then save the matching Box file ID separately. Do not treat the Transloadit result ID or URL as a Box identity or review link. Folder names and filenames can change, so reconcile before moves or renames and use the resolved Box ID for later operations. Notify collaborators only after confirming the intended campaign and source version.

Recover from collisions and partial failure

Test an unauthorized app, missing-folder creation, a destination where the Service Account lacks create permission, duplicate uploaded names, processing failure, and a successful resize followed by Box failure. A missing folder is normally created, not reported as a clean failure; check for an unintended private folder tree as well as explicit export errors. Box requires names to be unique within a parent folder; Assembly uniqueness in the sample path prevents an unrelated existing file from becoming an accidental overwrite target.

A missed webhook or client timeout does not prove export failure. Reconcile the existing Assembly before retrying. If a new rendition is required, record it as a new campaign source or workflow version rather than silently replacing the file reviewers already discussed. Remove rejected and superseded review copies through a deliberate retention process.