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Real-time events forHedera smart contracts

The days of polling a mirror node are over! Create HashStream rules to receive instant webhooks for every smart contract transaction—no polling, no delays, no missed events. Enterprise-grade reliability built exclusively for Hedera developers.

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How It Works
// Hedera Smart Contract Event
{
  "eventName": "Transfer",
  "contractId": "0.0.12345",
  "timestamp": "2025-12-17T06:27:59.214Z",
  "parameters": {
    "from": "0x1234...5678",
    "to": "0x8765...4321",
    "amount": "1000000"
  },
  "transactionHash": "0xa1b2c3..."
}
Webhook delivered in 238ms
Status code 200

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Features

A better way to monitor your smart contracts

HashStream provides powerful tools for developers building on the Hedera blockchain.

Real-time Notifications

Receive instant webhooks whenever your smart contracts emit events. No more polling or missed transactions.

Enterprise Reliability

Built for mission-critical applications with 99.99% uptime SLA. Multiple redundancy layers ensure you never miss an event.

Developer-Friendly API

Simple integration with webhooks to your existing endpoints. Comprehensive SDK and documentation make setup a breeze.

How It Works

Three simple steps to get started

  1. 1

    Register your contract

    Enter your contract ID and network through our simple interface or API.

    // Define a contract
{
  "contractId": "0.0.12345",
  "network": "mainnet"
}
  2. 2

    Configure webhooks

    Add your webhook URL to receive real-time notifications. Test your endpoint with sample events before deploying to production.

    // Configure webhook
{
  "endpoint": "https://api.yourapp.com/events",
  "headers": {
    "x-api-key": "your-secret"
  },
  "retryPolicy": "exponential"
}
  3. 3

    Receive events

    Sit back and let HashStream do the work. Get instant notifications whenever your contracts emit events, with detailed payload data.

    // Webhook payload
{
  "id": "evt_12345",
  "event": "Transfer",
  "contractId": "0.0.12345",
  "data": {
    "from": "0x123...",
    "to": "0x456...",
    "amount": "100000"
  },
  "timestamp": "2025-03-15T13:45:30Z"
}

FAQ

Common Questions

What is a smart contract event subscription?
It's a service that monitors the blockchain for specific events emitted by smart contracts you're interested in, then notifies your application in real-time when those events occur.
How is this better than polling the blockchain?
Polling is inefficient and can miss events or introduce delays. Our subscription service is real-time, more reliable, and reduces your infrastructure costs and complexity.
What blockchains do you support?
Currently, we specialize in the Hedera blockchain to provide the best possible service with deep expertise. We are all in on Hedera and have no plans to support other blockchains at this time.
How secure is the service?
We use industry-standard encryption, authentication, and authorization practices. Your API keys and webhook endpoints are securely stored and all communications are encrypted.

Ready to get started?Create your account today.

Start receiving real-time notifications for your smart contracts in minutes.

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