Skip to main content

​
Use Case

You want to stream only USDC transfers on Base Mainnet into Postgres, with amounts converted from raw units to human-readable values. This is useful for compliance monitoring, whale watching, or building token-specific analytics.

​
Pipeline Configuration

1

Create a new pipeline

In the GoldRush Platform, navigate to Manage Pipelines and click Create Pipeline. Name it usdc-whale-watch.
2

Configure the Postgres destination

Select Postgres as the destination type:
destination:
  type: "postgres"
  url: "postgresql://your-host:5432/compliance"
  user: "${PG_USER}"
  password: "${PG_PASSWORD}"
  batch_size: 500
3

Select your source

Choose Base Mainnet as the chain and Transfers as the data type. This streams every token and native transfer on Base.
4

Add a SQL transform

Filter to USDC transfers only and convert the raw amount to a human-readable decimal value. USDC on Base has 6 decimals:
transforms:
  transfers: >
    SELECT block_height, block_signed_at, tx_hash,
           from_address, to_address,
           CAST(amount AS DOUBLE) / 1000000 AS amount_usdc
    FROM transfers
    WHERE contract_address = '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913'
5

Deploy

Review and deploy. Only USDC transfers flow to your database - all other tokens are filtered out before reaching the destination.

​
How the Transform Works

The SQL transform runs inside the pipeline, before data reaches your database:
  1. WHERE clause filters to only transfers where the contract_address matches USDC on Base
  2. CAST and arithmetic converts the raw amount (stored as a string of the integer value in smallest units) to a DOUBLE divided by 10^6
  3. SELECT projects only the columns you need, reducing storage
This means your Postgres database only stores the data you care about - no wasted writes for irrelevant tokens.

​
Verify Data

SELECT block_height, tx_hash, from_address, to_address, amount_usdc
FROM usdc_whale_watch.transfers
ORDER BY amount_usdc DESC
LIMIT 20;

​
Extending to Multiple Tokens

To track multiple tokens, expand the WHERE clause with an IN filter: 
transforms:
  transfers: >
    SELECT block_height, block_signed_at, tx_hash, contract_address,
           from_address, to_address, amount
    FROM transfers
    WHERE contract_address IN (
      '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913',
      '0x4200000000000000000000000000000000000006',
      '0x50c5725949A6F0c72E6C4a641F24049A917DB0Cb'
    )
When tracking multiple tokens with different decimal places, keep the raw amount as a string and handle decimal conversion in your application layer instead.

​
Production Tips

  • Batch size: A smaller batch size (500) is appropriate here because the SQL transform filters out most records, resulting in lower write throughput to the destination.
  • Indexing: Add indexes on from_address, to_address, and amount_usdc for common query patterns.
  • Alerting: Combine this pipeline with a simple cron job or application query to trigger alerts when amount_usdc exceeds a threshold.