Ethereum in realtime: Dagger

Simple engine to get Ethereum transactions, receipts and events in realtime

Jaynti Kanani
Dec 6, 2017 · 2 min read

Somedays ago, someone sent random transaction to Parity Wallet and accidentally locked funds. No one knew about it until that person informed the team on Github. Currently there is no way to receive transaction (filtered) events from Ethereum and process them.

Etherscan sends you an email whenever anyone deposits to your accounts. But we need more ways to get informed whenever something happens on contracts. Simple example: getting a slack message or mobile notification when someone withdraws more than 10ETH or 1000 Tokens from your Multi-sig wallet?

To make that possible, we have created Dagger. We at Matic Network aim to make current decentralized eco-system more usable and easy for users and we believe Dagger helps developers to achieve that.

Dagger

Dagger is a simple development tool to get blocks, transactions or events triggered by Ethereum blockchain.

It uses pub/sub mechanism (MQTT protocol). Once you subscribe particular topic, you will start receiving messages that matches subscribed topic.

You can subscribe as many as topics you want.

We have already created javascript library which you use on Node and browser as well. You can use one of any available MQTT libraries to interact with Dagger.

Get latest Ethereum block using Dagger

Use cases

Here are some use-cases (not limited)

  • Send emails to your DApp users when their contracts get created and they are ready to use
  • Watch ERC20 token transfer from particular address
Watch ERC20 token transfer from mentioned address
  • Receive slack messages when someone withdraws 1000 tokens
  • Automatically send broadcast new transaction when future block ‘X’ gets created
  • … and many more …

You can connect Dagger with any third party services using IFTTT or Zapier.

Here is an example to store every outgoing Aragon Multisig Wallet transaction into Airtable.

Here are useful links:

Dagger: https://matic.network/dagger
Dagger examples: https://github.com/jdkanani/eth-dagger-examples
Javascript library: https://github.com/maticnetwork/eth-dagger.js

Let us know how we can make Dagger better for developers to help them make better DApps.

Stay in touch with us by following us on Twitter.

Matic Network

Secure, scalable and instant transactions for everyone.

Medium is an open platform where 170 million readers come to find insightful and dynamic thinking. Here, expert and undiscovered voices alike dive into the heart of any topic and bring new ideas to the surface. Learn more

Follow the writers, publications, and topics that matter to you, and you’ll see them on your homepage and in your inbox. Explore

If you have a story to tell, knowledge to share, or a perspective to offer — welcome home. It’s easy and free to post your thinking on any topic. Write on Medium

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store