This workflow automatically monitors the Ethereum blockchain, extracts USDT transfer events, filters large-value transactions, stores them in Airtable, and sends a clean daily summary alert to Slack.
This workflow checks the latest Ethereum block on a daily basis and identifies high-value USDT transfers. It fetches on-chain logs using Alchemy, extracts sender, receiver, and value details, filters transactions above a defined threshold, stores them in Airtable, and sends a single, concise summary alert to Slack.
You receive:
- Daily blockchain check (fully automated)
- Airtable tracking of all high-value USDT transfers
- Slack alert summarizing total count and largest transfer
Ideal for teams needing simple, automated visibility into large or suspicious crypto movements without manually scanning the blockchain.
- Add your Alchemy Ethereum Mainnet API URL to both HTTP Request nodes.
- Connect and configure your Airtable base and table.
- Connect your Slack credentials and select the alert channel.
- Adjust the value threshold in the IF node (default:
1,000,000,000). - Activate the workflow — daily monitoring begins immediately.
This workflow automates detection of high-value USDT transfers on Ethereum:
- Fetches the latest Ethereum block number using Alchemy.
- Retrieves all USDT Transfer (ERC-20) logs from that block.
- Extracts structured transaction data:
- Sender address
- Receiver address
- Transfer amount
- Token contract
- Block number
- Transaction hash
- Filters only transactions above a configurable value threshold.
- Stores each qualifying transaction in Airtable.
- Generates a daily summary:
- Total number of high-value transfers
- Largest single transfer
- Sends one clean summary alert to Slack.
This prevents alert spam while maintaining full visibility.
This workflow is ideal for:
- Crypto analytics teams
- Blockchain monitoring platforms
- Compliance and risk teams
- Web3 product teams
- Developers tracking USDT movements
- Anyone monitoring whale or suspicious transactions
To run this workflow, you need:
- n8n account (cloud or self-hosted)
- Alchemy API URL (Ethereum Mainnet)
- Airtable account with Personal Access Token
- Slack workspace with API permissions
- Basic familiarity with Ethereum logs and hex data
- Daily Trigger – Workflow runs at a scheduled time.
- Get Latest Block – Fetches the most recent Ethereum block.
- Fetch USDT Logs – Queries ERC-20
Transferevents. - Extract Transaction Details – Converts hex values into readable numbers.
- Filter High-Value Transfers – Keeps only large transactions.
- Save to Airtable – Logs each transaction for tracking.
- Generate Summary – Identifies the largest transfer and total count.
- Send Slack Alert – Posts one clean daily summary.
-
Import the provided workflow JSON into n8n.
-
Open the Get Latest Block and Fetch Logs HTTP nodes and paste your Alchemy API URL.
-
Confirm the USDT contract address (preconfigured):
-
Connect your Airtable account and map these fields:
- Contract
- From Address
- To Address
- Value
- Block Number
- Transaction Hash
- Connect Slack API credentials and select a channel.
- Adjust the threshold in the IF node if required.
- Activate the workflow.
In the IF node, you can:
- Increase or decrease the minimum transfer size
- Switch logic for aggressive or conservative whale tracking
Add optional fields such as:
- Timestamp
- Token symbol
- USD value
- Transaction status
- Risk or severity level
Enhance notifications with:
- Emojis and formatting
- Mentions (
@channel,@team) - Etherscan links
- Highlighted critical transactions
Replace Alchemy with:
- Infura
- QuickNode
- Other RPC providers (public RPCs not recommended)
You can extend this workflow to:
- Monitor multiple ERC-20 tokens
- Process multiple blocks per run
- Convert token values to USD
- Detect transfers to known or suspicious wallets
- Generate weekly or monthly reports
- Build dashboards using Airtable Interfaces
- Add AI-based anomaly detection
Detect large USDT movements (e.g., >1M or >5M).
Maintain an auditable log of high-value transfers.
Receive one clean Slack alert per day.
Structured extraction of Ethereum event logs.
Track large inflows and outflows to known wallets.
| Issue | Possible Cause | Solution |
|---|---|---|
| No data in Airtable | No Transfer logs in the latest block | Confirm USDT transfers occurred in that block |
| Transfer value is zero | Hex parsing logic incorrect | Verify extraction and conversion code |
| Slack alert not sent | Invalid Slack credentials or channel ID | Recheck Slack API token and channel |
| Airtable error | Field or table name mismatch | Match Airtable column names exactly |
| HTTP request fails | Invalid Alchemy API URL | Verify API key and endpoint |
| Workflow not running | Trigger disabled | Enable the Daily Trigger node |
If you need help extending or scaling this workflow — multi-token tracking, dashboards, enhanced alerts, or production hardening — the WeblineIndia team can assist with advanced Web3 automation and monitoring solutions.