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API Documentation
Enterprise Feature: REST API access is available on the Enterprise plan ($499/month). Contact us to get your dedicated API key.
Overview
The HashNotary API allows you to programmatically certify documents, verify seals, and manage your certification pipeline. It's designed for organizations that need to process high volumes of documents automatically.
Authentication
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json
Endpoints
POST /api/documents/certify
Submit a document hash for blockchain certification.
POST /api/documents/certify
{
"hash": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
"filename": "contract-2026.pdf",
"metadata": {
"client": "Acme Corp",
"type": "legal"
}
}
Response 201:
{
"id": "cert_abc123",
"hash": "e3b0c44...",
"txHash": "0x7f9e...",
"blockNumber": 52847391,
"timestamp": "2026-03-26T20:00:00Z",
"verifyUrl": "https://hashnotary.io/verify/cert_abc123",
"qrCode": "data:image/png;base64,..."
}
GET /api/documents/verify/:hash
Verify if a document hash has been certified.
GET /api/documents/verify/e3b0c44298fc1c149afbf4c8996fb924...
Response 200:
{
"verified": true,
"certifiedAt": "2026-03-26T20:00:00Z",
"txHash": "0x7f9e...",
"blockNumber": 52847391,
"certifier": "0x742d35Cc..."
}
GET /api/documents/list
List all your certified documents.
POST /api/documents/batch
Certify multiple documents in a single API call (up to 100).
Webhooks
Receive real-time notifications when certifications are confirmed on-chain:
POST your-webhook-url
{
"event": "certification.confirmed",
"data": {
"id": "cert_abc123",
"hash": "e3b0c44...",
"txHash": "0x7f9e...",
"confirmedAt": "2026-03-26T20:00:05Z"
}
}
Rate Limits
- Enterprise: 1,000 requests/minute
- Batch: Up to 100 documents per request
SDKs & Libraries
Coming soon: JavaScript/Node.js, Python, and Go SDKs.