iOS + Transloadit

Build the integration

This Swift helper creates an Assembly from one Template, queues a local file for upload, and polls its status. Your app supplies the authenticated signing integration described in the TransloaditKit guide.

1. Install TransloaditKit exactly 3.5.0 with Swift Package Manager or CocoaPods. Swift Package Manager pins TUSKit to 3.6.0; keep the resolved dependency versions with your project.
2. Create a server-owned Template with Step overrides disabled and require Signature Authentication. Configure the backend to allow only the intended workflow, following the TransloaditKit signing and usage guide.
3. Replace the Auth Key, Template ID, and local file path placeholders, then call createAssembly with your app’s synchronous SignatureGenerator and handlers for completion and statusChanged.
4. Call createAssembly off the main thread, retain the returned Transloadit client for the operation, and dispatch UI updates to the main queue. Handle failures in both callbacks.

// Swift Package Manager:
// .package(url: "https://github.com/transloadit/TransloaditKit", exact: "3.5.0")
// Or CocoaPods: pod 'Transloadit', '3.5.0'
// Pin its dependency too: pod 'TUSKit', '3.6.0'

import Foundation
#if canImport(TransloaditKit)
import TransloaditKit
#else
import Transloadit
#endif

// TransloaditKit 3.5.0. Supply your app’s authenticated signing integration.
// Its backend must authorize params, expiry, processing and destination policy,
// then sign the exact original UTF-8 bytes. Do not reserialize them.
// The signing completion is nonescaping: call it synchronously exactly once
// before the signature generator returns, including denial and timeout.
// Use synchronous transport with a finite timeout, off the main thread.
// The SDK fixes a 24-hour expiry; use backend creation if policy requires less.
// Retain the returned client for the operation’s lifetime.
// Signing guide: https://transloadit.com/docs/sdks/transloaditkit/#user-content-transloaditkit-usage
func createAssembly(
  signatureGenerator: @escaping SignatureGenerator,
  configuration: URLSessionConfiguration = .default,
  completion: @escaping (Result<Assembly, TransloaditError>) -> Void,
  statusChanged: @escaping (Result<AssemblyStatus, TransloaditError>) -> Void
) -> Transloadit {
  let transloadit = Transloadit(
    apiKey: "YOUR_TRANSLOADIT_KEY",
    sessionConfiguration: configuration,
    signatureGenerator: signatureGenerator
  )

  // Replace these paths with local file URLs from your app.
  let filesToUpload: [URL] = [
    URL(fileURLWithPath: "/path/to/file.jpg"),
  ]

  transloadit.createAssembly(templateId: "YOUR_TRANSLOADIT_TEMPLATE_ID", andUpload: filesToUpload, completion: completion)
    .pollAssemblyStatus(completion: statusChanged)
  return transloadit
}

Authentication

• Pass the public Auth Key and your app’s authenticated SignatureGenerator to the helper. Keep the Auth Secret on the backend and require Signature Authentication for the Workspace or Template.
• The backend must authenticate the user and authorize the exact Auth Key, Template, fields, processing, destinations, and expiry before signing the original UTF-8 params bytes. Reject extra Steps and unknown options; matching template_id alone is insufficient.
• TransloaditKit 3.5.0 uses a nonescaping signing completion. Call it exactly once before the SignatureGenerator returns, including denial and timeout, using synchronous transport with a finite timeout off the main thread.

Limitations and operational notes

• The SDK fixes auth.expires at 24 hours and the signing callback cannot replace the params. If your policy requires a shorter expiry, reject the request and use backend Assembly creation.
• This helper covers one Template and local files. TransloaditKit 3.5.0 cannot combine a Template with Step overrides or set arbitrary Assembly and auth options; use backend Assembly creation when those controls are required.
• The create callback means the Assembly exists and uploads were scheduled; it does not mean file upload or processing has finished.
• The SDK’s expected file count is outside signed params and is not an authorization limit. Enforce quotas and file restrictions through the server-owned workflow; use backend Assembly creation if the Template cannot enforce your requirements.
• The helper requires your app’s login and signing transport. Background scheduling, resumability, lifecycle handling, and file access need integration and testing on your target devices.