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Overview

Launch includes a production-ready file upload system that supports:
  • Secure uploads via S3 presigned URLs (no credentials exposed to client)
  • Resumable multipart uploads for large files
  • Native background uploads for iOS/Android (survives app backgrounding)
  • Parallel uploads for multiple files
  • Progress tracking with persistence across navigation

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Prerequisites

  • S3 bucket and credentials
  • Backend running with S3 env vars (copy from apps/api/example.env)
  • File uploads feature enabled in apps/mobile/features/feature-registry.tsx

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Architecture

┌─────────────────────────────────────────────────────────────────┐
│                        Upload Flow                               │
├─────────────────────────────────────────────────────────────────┤
│                                                                  │
│   Mobile App                    Backend API              AWS S3  │
│   ──────────                    ───────────              ──────  │
│                                                                  │
│   1. Select file ──────────────►                                 │
│                                                                  │
│   2. Request URL ──────────────► Validate user                   │
│                                  Check quota                     │
│                                  Generate presigned URL ◄──────► │
│                    ◄──────────── Return URL                      │
│                                                                  │
│   3. Upload file ──────────────────────────────────────────────► │
│                                                                  │
│   4. Confirm ──────────────────► Mark as uploaded                │
│                                  Update user storage             │
│                    ◄──────────── Success                         │
│                                                                  │
└─────────────────────────────────────────────────────────────────┘

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Upload Strategies

Launch automatically selects the best upload strategy based on file size:
File SizeStrategyDescription
< 10 MBSimple UploadSingle presigned URL PUT request
10-40 MBMultipart UploadChunked upload with 5MB parts, resumable
> 40 MBNative BackgroundiOS URLSession / Android coroutines

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Features

Presigned URLs

Secure, time-limited URLs. No S3 credentials on client.

Resumable

Multipart uploads can resume after network interruption.

Background Uploads

Native iOS/Android uploads continue when app is backgrounded.

Progress Tracking

Per-file progress with UI persistence across navigation.

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Steps

  1. Configure S3 and backend env vars: Backend Setup
  2. Integrate the mobile UI: Mobile Setup
  3. Enable the feature flag:
apps/mobile/features/feature-registry.tsx → featureFlags.fileUploads = true

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How It Works

  • Mobile requests presigned URLs from the API
  • Uploads go directly to S3
  • The API confirms and records uploads

Backend Setup

Configure S3, environment variables, and API endpoints.

Mobile Setup

Integrate file uploads in your React Native app.

Native Uploads

Deep dive into iOS/Android background upload module.

API Reference

Complete API documentation for upload endpoints.

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Test Checklist

  • Select a photo and upload successfully
  • Large file triggers multipart or native upload
  • Uploaded file appears in the list

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Troubleshooting

Start with Troubleshooting and verify S3 credentials and CORS configuration.

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Remove / Disable

To disable uploads while you configure S3, set: apps/mobile/features/feature-registry.tsx → featureFlags.fileUploads = false For production removal guidance, see Removing Features.

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Next Steps