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Tutorial to subscribe to ERC20 Token deposits of an Ethereum address

This tutorial will show you how to receive automated messages when you receive money on the selected Ethereum address. The only thing needed is a Ethereum address where the money will land and a URL where the notification will be sent.

  1. Basic knowledge of Nodejs
  2. Account at Chaingateway.io
  3. A local or remote machine with Python3 and installed requests and json modules

IPN Receiver (simple example in express.js)

  1. Create an python web server (e.g. flask) and create a secure post route (example: /B5tN-KtfOTf37)
  2. Upload the following code for creating the post route
  3. The code will always the send the request body to the console log as soon as the subscribed event occurs in the blockchain. You can process deposits the way you want of course (Example: Update user balances, Mark orders as paid, …).
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    from flask import Flask,request,json

    app = Flask(__name__)

    @app.route('/B5tN-KtfOTf37',methods=['POST'])
    def webhookreceiver():
    data = request.json
    print(data)
    return data

run it with ´´´python3 YOURFILENAME.py´´´

Subscribing to an Blockchain-Event

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    import requests
    import json

    ############################
    # Replace with your Values #
    ############################
    apikey = "YOURAPIKEY"; # API Key in your account panel
    contractaddress = "CONTRACTADDRESS"; # Contract address of the token you want to watch
    ethereumaddress = "ETHEREUMADDRESS"; # Ethereum address you want to watch
    yoururl = "https://yoururl.com/ipnreceiver"; # URL where you want to receive updates

    
    url = "https://api.chaingateway.io/v2/ethereum/webhooks"

    payload = json.dumps({"contract": contractaddress, "to": ethereumaddress, "url": yoururl})

    headers = {
    'Accept': 'application/json',
    'Authorization': apikey
    }

    response = requests.request("POST", url, headers=headers, data=payload)

    print(response.text)

Code Modifications

  1. Replace “YOURAPIKEY” in above code with the API Key in your Chaingateway.io Account Panel.
  2. Replace “ETHEREUMADDRESS” in above code with Contract address of the token you want to watch.
  3. Replace “CONTRACTADDRESS” in above code with the ethereum address you want to watch.
  4. Replace “https://yoururl.com/ipnreceiver” in above code with the URL you want to receive updates.

Final Steps

  1. Upload the code above to your local or remote machine
  2. Call the script for subscribing to your event
  3. After a few seconds, the script will return a status showing if the request was successful.

Congratulations! You just created an address subscription and will receive notifications on future deposits to the provided url.