How to Run an AI Blockchain & Web3 Agent with OE Runtime

Query Ethereum wallets, transactions, and smart contracts with natural language. OE Runtime lets you run a local Web3 agent — fetch balances, analyse transaction history, and surface on-chain insights without writing a single line of code.

The Agent YAML

Create a file called agent.yaml inside a blockchain-web3/ directory:

name: Blockchain Agent
description: Query wallet balances, transactions, and smart contracts
instructions: |
  You are a blockchain data agent. Query wallet balances, transaction history,
  token holdings, and smart contract state on Ethereum and EVM-compatible chains.
  Complete all steps fully before writing your report.
steps:
  - name: Fetch Wallet Data
    content: |
      Query the latest block number and get the ETH balance for the wallet address configured in the connector.
      Also fetch the last 5 transactions for that wallet.
  - name: Analyze Transactions
    content: |
      For each of the 5 transactions retrieved:
      - Identify direction (sent / received)
      - Convert value from Wei to ETH
      - Note the counterparty address and timestamp
  - name: Report
    content: |
      Produce a wallet summary:
      - Current ETH balance
      - Total sent vs received across the 5 transactions
      - Most recent transaction details
      - Any unusual patterns (large transfers, repeated counterparties)
connectors:
  - connection_name: Ethereum
    connection_type: web3

The Config File

Create oe-config.json in the same directory:

{
  "llm": {
    "provider": "openai",
    "model": "gpt-4o",
    "apiKey": "YOUR_OPENAI_API_KEY"
  },
  "server": {
    "enabled": false,
    "port": 3333,
    "apiKey": "your-secret-api-key"
  },
  "connectors": [
    {
      "connection_name": "Ethereum",
      "connection_type": "web3",
      "provider": "infura",
      "apiKey": "YOUR_INFURA_PROJECT_ID",
      "network": "mainnet"
    }
  ]
}

Replace YOUR_INFURA_PROJECT_ID with your key from app.infura.io. You can also use Alchemy, QuickNode, or any EVM-compatible RPC endpoint.

Download OE Runtime

Run the Agent

Windows

# Run the agent
oe-runtime-win.exe blockchain-web3/agent.yaml --config blockchain-web3/oe-config.json

macOS

# Make executable (first time only)
chmod +x oe-runtime-macos

# Run the agent
oe-runtime-macos blockchain-web3/agent.yaml --config blockchain-web3/oe-config.json

Linux

# Make executable (first time only)
chmod +x oe-runtime-linux

# Run the agent
oe-runtime-linux blockchain-web3/agent.yaml --config blockchain-web3/oe-config.json

Running as an API Server

Add --serve to start OE Runtime as an HTTP server on port 3333:

oe-runtime-win.exe --serve --config blockchain-web3/oe-config.json

Then send a request:

curl -X POST http://localhost:3333/run \
  -H "Content-Type: application/json" \
  -d '{"yaml": "blockchain-web3/agent.yaml", "params": {}}'

Or import the Postman collection (download above) to test all endpoints visually.

Use Cases

• Wallet auditing — Review the complete transaction history, token holdings, and ETH balance for any wallet address. Useful for compliance teams verifying that company wallets have not made unauthorised transfers or interacted with flagged contracts.
• DeFi portfolio monitoring — Track wallet positions across DeFi protocols by querying on-chain state directly. Get a consolidated view of lending positions, liquidity pool shares, and token balances without relying on third-party dashboards.
• Treasury management — Monitor DAO or company treasury wallets for incoming and outgoing transfers in real time. Set up the agent as an API server to trigger alerts whenever a transfer above a threshold is detected.
• On-chain due diligence — Research counterparty wallet history before entering a token deal or smart contract interaction. Surface red flags like interactions with mixer contracts, rapid fund movements, or connections to flagged addresses.
• NFT ownership verification — Confirm token ownership and provenance on-chain before processing a transfer or listing. Query the ERC-721 or ERC-1155 contract to get the current holder, mint date, and full transfer history.
• Smart contract inspection — Query the state variables and recent event logs of any deployed smart contract. Useful for developers auditing their own contracts or for analysts monitoring protocol activity.
• Transaction forensics — Trace the flow of funds across multiple wallet hops to reconstruct a payment path. Combine with the reporting step to produce a clear chain-of-custody document for legal or compliance purposes.
• Automated reporting — Run the agent on a schedule to generate daily or weekly blockchain activity reports for stakeholders. Deliver summaries of treasury movements, gas costs, and protocol interactions without manual data collection.