Continuata • Downloader

Content-Addressed Storage

Traditional file storage uses human-readable names that can change or conflict. Content-addressed storage uses the file's cryptographic hash as its identifier, creating several powerful benefits:

How It Works

When you upload a file, Continuata calculates its SHA-256 hash
The file is stored using this hash as the key (e.g., a3c2b1...)
Multiple files with identical content share the same storage space
File integrity can be verified by recalculating the hash

Benefits

• Automatic deduplication
• Tamper detection
• Efficient delta updates
• Immutable references

Use Cases

• Sample library versions
• Plugin distributions
• Software updates
• Asset collections

Delta Updates

When you release a new version of your product, users only download the files that have changed. This dramatically reduces download times and bandwidth usage.

Example: Sample Pack Update

Version 1.0

Version 1.1

User Downloads

kick_01.wav

kick_02.wav

snare_01.wav

readme.txt

kick_01.wav (same)

kick_02.wav (modified)

snare_01.wav (same)

readme.txt (updated)

kick_03.wav (new)

— (skipped)

✓ kick_02.wav

— (skipped)

✓ readme.txt

✓ kick_03.wav

In this example, the user downloads only 3 files instead of 5, saving 40% of the bandwidth and time.

Cryptographic Verification

Every file and chunk includes SHA-256 checksums to ensure perfect data integrity throughout the download process.

Manifest Signing

The manifest file listing all content is cryptographically signed to prevent tampering.

Pack Verification

Each ~8MB pack is verified against its expected SHA-256 hash after download, before any files are extracted from it.

File Extraction

Each file is extracted from its pack using a byte offset and length. Its SHA-256 is then verified against the manifest before it is written to disk.

Corruption Handling

If a pack fails size or hash verification, it is automatically retried up to three times with backoff. Corrupted data never reaches the user's filesystem.

Browser-Native Downloads

Continuata runs directly in Chrome and Edge without any installation. Safari and Firefox are supported via the free Continuata Bridge desktop app.

File System Access API

Modern browsers support direct file system access, allowing native-like folder selection and file writing.

Chrome

Full native support

Edge

Full native support

Firefox

Bridge required

Safari

Bridge required

Origin Private File System (OPFS)

For browsers without the File System Access API and without the Bridge installed, Continuata can use OPFS as a staging area before exporting files as a ZIP.

Continuata Bridge

A free desktop companion app that provides native file system access for browsers that need it — Safari and Firefox.

Download Resume

Download progress is persisted in the browser's IndexedDB. If the page is closed or refreshed mid-download, a Resume Download button appears on the next visit. The download continues from the last completed pack — no data is re-downloaded.

Manifest Structure

The manifest is a JSON file that describes your product's files, their hashes, and download URLs.

{
  "v": 3,
  "vendorId": "audio-company",
  "productId": "epic-drums-v1",
  "productHash": "abc123...",
  "version": "1.0.0",
  "folderName": "epic-drum-kit-v1",
  "packs": [
    {
      "key": "audio-company/packs/pack-deadbeef...",
      "sha256": "deadbeef...",
      "size": 8388608
    }
  ],
  "files": [
    {
      "path": "samples/kick_01.wav",
      "size": 2097152,
      "sha256": "a1b2c3d4e5f6...",
      "segments": [
        { "pack": 0, "offset": 0, "length": 2097152 }
      ]
    },
    {
      "path": "samples/snare_01.wav",
      "size": 2097152,
      "sha256": "b2c3d4e5f6a1...",
      "segments": [
        { "pack": 0, "offset": 2097152, "length": 2097152 }
      ]
    }
  ],
  "totalSize": 1073741824,
  "fileCount": 4789,
  "signature": "manifest_signature_here",
  "expiresAt": 1640995200000
}

Global CDN Architecture

Continuata leverages a global edge network for optimal performance and fast, reliable delivery.

Edge Caching

• 285+ cities worldwide
• Intelligent cache warming
• Automatic compression
• HTTP/2 and HTTP/3 support

Performance Benefits

• Sub-100ms latency globally
• Automatic failover
• DDoS protection included
• No bandwidth charges

Progressive Enhancement

Continuata is designed with progressive enhancement, providing the best possible experience based on browser capabilities.

Best Case: Modern Desktop Browsers

Direct file system access, parallel downloads, real-time progress, automatic resume

Good Case: Older Browsers

OPFS staging, ZIP export option, progress tracking, manual resume

Fallback: Legacy Browsers

Traditional single-file downloads with basic progress indication

Security Model

Multiple layers of security protect both content creators and end users.

Content Protection

• Time-limited download tokens
• IP-based access restrictions
• Download count limits
• Token revocation support

Data Integrity

• End-to-end encryption in transit
• Cryptographic verification
• Tamper-proof manifests
• Automatic corruption recovery

Ready to Implement?

Now that you understand how Continuata works, check out ourQuick Start Guide to upload your first product or explore platform integrations.

Core Concepts