🔐 Chain Verification

Chain Verification

Verify the cryptographic integrity of your SoWasIt blockchains offline, anytime, anywhere. No API key required for verification - complete transparency and independence.

Installation

Install via npm:

npm install @sowasit/chain-verifier

Or use directly with npx (no installation needed):

npx @sowasit/chain-verifier verify my-chain.json

CLI Usage

Verify a chain

You can verify either a local file or download and verify a chain by ID:

# Verify a local file
npx @sowasit/chain-verifier verify chain.json

# Download and verify a public chain
npx @sowasit/chain-verifier verify my-chain-id

# Download and verify a private chain
npx @sowasit/chain-verifier verify my-private-chain --api-key te_xxxxx

# Verify with detailed output
npx @sowasit/chain-verifier verify my-chain.json --verbose --output report.json

Options

• -o, --output <file> - Save verification report to a file
• -v, --verbose - Show detailed block-by-block results
• -k, --api-key <key> - API key (or use SOWASIT_API_KEY environment variable). Required only for private chains
• -u, --api-url <url> - API URL (default: https://api.sowasit.io)
• --force-download - Force re-download, ignoring local cache
• --include-anchors - Include anchor blocks for verification

Download a chain from API

Download a complete or partial chain from the SoWasIt API:

# Download a public chain
npx @sowasit/chain-verifier download my-public-chain-id

# Download a private chain
npx @sowasit/chain-verifier download my-chain-id --api-key te_xxxxx

# Download partial range of blocks
npx @sowasit/chain-verifier download my-chain-id --from 100 --to 200

Programmatic API

Verify a chain

import { verifyChain } from '@sowasit/chain-verifier';
import { readFile } from 'fs/promises';

// Load chain export
const chainData = JSON.parse(await readFile('chain.json', 'utf-8'));

// Verify
const result = verifyChain(chainData);

if (result.valid) {
  console.log(`✓ ${result.validBlocks} blocks are valid`);
} else {
  console.log(`✗ ${result.invalidBlocks} invalid blocks`);
  console.log('Errors:', result.errors);
}

Download a chain

import { downloadChain } from '@sowasit/chain-verifier';
import { writeFile } from 'fs/promises';

// Download public chain (no API key required)
const publicChainData = await downloadChain('public-chain-id', {
  apiUrl: 'https://api.sowasit.io',
});

// Download private chain (API key required)
const privateChainData = await downloadChain('private-chain-id', {
  apiKey: 'te_xxxxx',
  apiUrl: 'https://api.sowasit.io',
  from: 0,
  to: 100,
});

await writeFile('chain.json', JSON.stringify(privateChainData, null, 2));

Verification Process

Usage Examples

CI/CD Integration

Automate chain verification with GitHub Actions:

# .github/workflows/verify-chain.yml
name: Verify Chain Integrity

on:
  schedule:
    - cron: '0 0 * * *'  # Daily

jobs:
  verify:
    runs-on: ubuntu-latest
    steps:
      - name: Download chain
        run: |
          npx @sowasit/chain-verifier download ${{ secrets.CHAIN_ID }} \
            --api-key ${{ secrets.SOWASIT_API_KEY }} \
            --output chain.json

      - name: Verify chain
        run: |
          npx @sowasit/chain-verifier verify chain.json \
            --verbose \
            --output verification-report.json

      - name: Upload report
        uses: actions/upload-artifact@v3
        with:
          name: verification-report
          path: verification-report.json

Automatic Backup Script

Automatically download and verify your chains:

// backup-and-verify.js
import { downloadChain, verifyChain } from '@sowasit/chain-verifier';
import { writeFile } from 'fs/promises';

async function backupAndVerify() {
  const chainId = process.env.CHAIN_ID;
  const apiKey = process.env.SOWASIT_API_KEY;

  // Download
  console.log('Downloading chain...');
  const chainData = await downloadChain(chainId, { apiKey });

  // Save
  const filename = `backup-${chainId}-${new Date().toISOString()}.json`;
  await writeFile(filename, JSON.stringify(chainData, null, 2));
  console.log(`Saved to ${filename}`);

  // Verify
  console.log('Verifying...');
  const result = verifyChain(chainData);

  if (!result.valid) {
    throw new Error(`Verification failed: ${result.errors.join(', ')}`);
  }

  console.log(`✓ Backup verified: ${result.validBlocks} blocks`);
}

backupAndVerify().catch(console.error);

How It Works

SoWasIt uses double SHA-256 hashing (the same algorithm as Bitcoin) to ensure immutability:

1. Each block's data is serialized deterministically (JSON canonicalization)
  ↓
2. The data is hashed twice with SHA-256: SHA256(SHA256(data))
  ↓
3. Each block contains the hash of the previous block (prev_hash)
  ↓
4. Changing any bit in any block invalidates all subsequent blocks