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Introduction

This tutorial shows you how to detect and stream ERC-20 contract deployments in real time using The Neighborhood’s indexing infrastructure. Basically we are going to track new token creations. Unlike event-based pipelines, this example scans the entire chain for contract creation transactions and identifies which of these deployments implement the ERC-20 interface.
Note: The output of this pipeline can be used to trigger another pipeline that filters only the token transfers for these deployed tokens, creating a complete token tracking system.

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Prerequisites

You’ll need:
  • A Neighborhood API key. To get access, email hello@indexing.co
  • Basic understanding of EVM transactions and contract bytecode
  • curl or Postman
  • A webhook, database endpoint, or another supported delivery method

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What You’ll Build

A pipeline that:
  • Scans every block for contract creation traces
  • Detects contracts implementing the ERC-20 standard (using function selectors)
  • Streams structured deployment data to a destination of your choice
Delivery: Choose where the data should go: your database, a webhook, a Kafka topic - you name it! You can find the full list of supported destinations in our adapter directory.

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Step 1: Add the Transformation Logic

This transformation inspects each transaction trace within a block. If a contract is deployed and its bytecode contains known ERC-20 method selectors, it emits a record with the deployment details. 
function main(block) {
  const newContracts = [];

  const erc20InterfaceSignatures = [
    '18160ddd', // totalSupply()
    '70a08231', // balanceOf(address)
    'a9059cbb', // transfer(address,uint256)
    '23b872dd', // transferFrom(address,address,uint256)
    '095ea7b3', // approve(address,uint256)
    'dd62ed3e', // allowance(address,address)
  ];

  for (const tx of block.transactions) {
    if (!tx.receipt || !tx.traces?.length) continue;

    for (let ti = 0; ti < tx.traces.length; ti += 1) {
      const result = tx.traces[ti].result;
      if (result?.address && result.code) {
        if (!erc20InterfaceSignatures.find(fourByte => result.code.includes(fourByte))) {
          continue;
        }

        newContracts.push({
          chain: block._network.toLowerCase(),
          timestamp: new Date(block.timestamp * 1000),
          transactionHash: tx.hash,
          traceIndex: ti,
          address: result.address.toLowerCase(),
        });
      }
    }
  }

  return newContracts;
}
You can also download the code here

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Step 2: Create the Transformation

Use the following API request to create your transformation in The Neighborhood: 
curl https://app.indexing.co/dw/transformations/erc20_deployments \
  -H 'Content-Type: application/json' \
  -H 'X-API-KEY: <your-api-key>' \
  -F code=@./erc20_contract_deployments.js

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Step 3: Create the Pipeline

Since this pipeline scans all contract deployments, no filter step is required. Create the pipeline with: 
curl https://app.indexing.co/dw/pipelines \
  -H 'Content-Type: application/json' \
  -H 'X-API-KEY: <your-api-key>' \
  -d '{
    "name": "erc20_deployments_pipeline",
    "transformation": "erc20_deployments",
    "networks": [
      "base"
    ],
    "enabled": true,
    "delivery": {
      "adapter": "HTTP",
      "connection": {
        "host": "https://webhook.site/..."
      }
    }
  }'

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Step 4: Test the Stream

You can test the transformation logic against block 8925894 on Base, which contains a known ERC-20 deployment: 
[
  {
    "chain": "base",
    "timestamp": "2024-01-07T15:25:35.000Z",
    "transactionHash": "0xcea27f1618e28ecc59b2faed86cdec29a92218261fe9efe374a39201e93545c5",
    "traceIndex": 0,
    "address": "0x4ed4e862860bed51a9570b96d89af5e1b0efefed"
  }
]
Run this test with our Test endpoint: 
curl 'https://app.indexing.co/dw/transformations/test?network=base&beat=8925894' \
  -H 'X-API-KEY: <your-api-key>' \
  -F code=@./erc20_contract_deployments.js

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Wrap-Up

You’ve now set up a real-time pipeline for detecting ERC-20 contract deployments on The Neighborhood. To go further, chain this output into a second pipeline that filters and streams token transfers for these newly deployed tokens. Need help or want to go further?