Download System
How Continuata's download system works from the user's perspective and technical implementation details.
User Experience
Downloads work directly in Chrome and Edge — no installation required. Safari and Firefox users install the free Continuata Bridge for the same experience.
Click Download Link
Customer receives download URL via email or customer portal
Choose Location
Browser prompts for download folder using native file picker
Download with Progress
Real-time progress, speed indicators, and pause/resume controls
Verification & Completion
Automatic integrity verification and completion summary
Technical Architecture
Pack-Based Downloads
Files are grouped into ~8MB packs for transport. The downloader fetches packs sequentially, verifies each pack's SHA-256, then extracts and verifies each individual file before writing it to disk:
Benefits
- • Fewer HTTP requests (e.g. 150 packs vs 5,000 files)
- • Resume from last completed pack
- • Per-pack and per-file integrity verification
- • Automatic retry with backoff on failure
How It Works
- • Download pack → verify SHA-256
- • Extract files using segment offsets
- • Verify each file's SHA-256
- • Write verified files to disk
File System Integration
Different approaches based on browser capabilities:
File System Access API (Chrome, Edge)
Direct file system access allows writing files to user-selected folders in real-time during download.
Origin Private File System (OPFS)
For browsers without direct access, files are staged in OPFS then exported as a ZIP when complete.
Continuata Bridge
Free desktop app provides native file system access for Safari and Firefox.
Progress Tracking
Real-time download progress with detailed metrics:
Overall Progress
Percentage complete, bytes downloaded, total size
Current File
Active file name, file progress, circular indicator
Performance
Download speed, ETA, active connections
Browser Compatibility
Chrome
Full native support
Edge
Full native support
Firefox
Bridge required
Safari
Bridge required
Resume Downloads
Download progress is automatically persisted in the browser's IndexedDB. If the page is closed, refreshed, or the connection drops mid-download, a Resume Download button appears on the next visit. The download picks up from the last completed pack — no data needs to be re-downloaded.
- • Works across page refresh, tab close, and browser restart
- • Progress tracked at the pack level — completed packs are never re-fetched
- • The same download folder is re-used automatically (no folder picker prompt on resume)
Security Features
Data Integrity
- • SHA-256 verification per pack (after download)
- • SHA-256 verification per file (after extraction)
- • Automatic retry with backoff on pack failure
- • Cryptographically signed manifests
Access Control
- • Time-limited download tokens
- • IP-based restrictions (optional)
- • Download count limits
- • Token revocation capabilities
Next Steps
Learn how to create download tokens or explore download analytics to track usage.