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Contract

Contract resource provides operations for interacting with smart contracts on the Ethereum blockchain.

Operations​

Read Contract​

Call a read-only (view/pure) function on a smart contract.

Required Credentials: Ethereum RPC

Parameters:

  • Contract Address (required): The smart contract address
  • ABI (required): Contract ABI (Application Binary Interface) in JSON format
  • Function Name (required): Name of the function to call
  • Function Arguments (optional): Arguments for the function in JSON array format
  • Block (optional): Block number to query (default: latest)

Example:

{
  "contractAddress": "0x6B175474E89094C44Da98b954EedeAC495271d0F",
  "abi": "[{\"name\":\"balanceOf\",\"type\":\"function\",\"inputs\":[{\"name\":\"account\",\"type\":\"address\"}],\"outputs\":[{\"name\":\"\",\"type\":\"uint256\"}]}]",
  "functionName": "balanceOf",
  "args": "[\"0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb\"]"
}

Output:

{
  "result": "1000000000000000000"
}

Write Contract​

Execute a state-changing function on a smart contract.

Required Credentials: Ethereum RPC, Ethereum Account

Parameters:

  • Contract Address (required): The smart contract address
  • ABI (required): Contract ABI in JSON format
  • Function Name (required): Name of the function to call
  • Function Arguments (optional): Arguments for the function in JSON array format
  • Value (optional): ETH to send with transaction (in ether)
  • Gas Limit (optional): Maximum gas to use
  • Max Fee Per Gas (optional): Maximum total fee per gas
  • Max Priority Fee Per Gas (optional): Maximum priority fee per gas

Example:

{
  "contractAddress": "0x6B175474E89094C44Da98b954EedeAC495271d0F",
  "abi": "[{\"name\":\"transfer\",\"type\":\"function\",\"inputs\":[{\"name\":\"to\",\"type\":\"address\"},{\"name\":\"amount\",\"type\":\"uint256\"}]}]",
  "functionName": "transfer",
  "args": "[\"0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb\", \"1000000000000000000\"]"
}

Output:

{
  "hash": "0x1234567890abcdef...",
  "from": "0xYourAddress...",
  "to": "0x6B175474E89094C44Da98b954EedeAC495271d0F"
}

Deploy Contract​

Deploy a new smart contract to the blockchain.

Required Credentials: Ethereum RPC, Ethereum Account

Parameters:

  • Bytecode (required): Contract bytecode (from compilation)
  • ABI (required): Contract ABI
  • Constructor Arguments (optional): Arguments for constructor
  • Value (optional): ETH to send with deployment
  • Gas Limit (optional): Maximum gas to use

Example:

{
  "bytecode": "0x608060405234801561001057600080fd5b50...",
  "abi": "[{\"type\":\"constructor\",\"inputs\":[{\"name\":\"_name\",\"type\":\"string\"}]}]",
  "args": "[\"MyToken\"]"
}

Output:

{
  "hash": "0x1234567890abcdef...",
  "contractAddress": "0xNewContractAddress..."
}

Multicall​

Batch multiple read operations into a single call for efficiency.

Required Credentials: Ethereum RPC

Parameters:

  • Calls (required): Array of calls to execute
    • Each call contains: contract address, ABI, function name, arguments

Use Cases:

  • Read multiple values from one or more contracts in a single call
  • Reduce RPC calls and improve performance
  • Ensure all reads are from the same block

Example:

{
  "calls": [
    {
      "address": "0x...",
      "abi": "[...]",
      "functionName": "balanceOf",
      "args": "[\"0x...\"]"
    },
    {
      "address": "0x...",
      "abi": "[...]",
      "functionName": "totalSupply",
      "args": "[]"
    }
  ]
}

Simulate Contract​

Test a contract call without sending a transaction.

Required Credentials: Ethereum RPC

Parameters:

  • Contract Address (required): The smart contract address
  • ABI (required): Contract ABI
  • Function Name (required): Name of the function
  • Function Arguments (optional): Arguments for the function
  • Value (optional): ETH to simulate sending
  • From (optional): Address to simulate call from

Use Cases:

  • Test transactions before sending
  • Verify contract behavior
  • Check for revert reasons

Get Logs​

Query historical event logs from smart contracts.

Required Credentials: Ethereum RPC

Parameters:

  • Contract Address (optional): Filter by contract address
  • Event ABI (required): ABI of the event to decode
  • From Block (optional): Starting block number
  • To Block (optional): Ending block number
  • Topics (optional): Filter by indexed event parameters

Use Cases:

  • Query historical events
  • Track token transfers
  • Monitor contract activity

Example:

{
  "address": "0x6B175474E89094C44Da98b954EedeAC495271d0F",
  "eventAbi": "{\"name\":\"Transfer\",\"type\":\"event\",\"inputs\":[{\"name\":\"from\",\"type\":\"address\",\"indexed\":true},{\"name\":\"to\",\"type\":\"address\",\"indexed\":true},{\"name\":\"value\",\"type\":\"uint256\"}]}",
  "fromBlock": "18000000",
  "toBlock": "18000100"
}

Common Use Cases​

Read Contract State​

[Schedule Trigger] → [Read Contract] → [Store Data]

Execute Contract Function​

[Trigger] → [Write Contract] → [Wait For Transaction] → [Success Handler]

Deploy and Initialize Contract​

[Trigger] → [Deploy Contract] → [Wait For Transaction] → [Write Contract] → [Initialize]

Query Historical Events​

[Schedule Trigger] → [Get Logs] → [Process Events] → [Store in Database]

ABI Format​

The ABI (Application Binary Interface) defines the contract's interface. You can get it from:

  • Contract verification on Etherscan
  • Compiler output (Hardhat, Foundry, etc.)
  • Contract documentation

Minimal ABI Example:

[
  {
    "name": "transfer",
    "type": "function",
    "inputs": [
      {"name": "to", "type": "address"},
      {"name": "amount", "type": "uint256"}
    ],
    "outputs": [
      {"name": "", "type": "bool"}
    ]
  }
]

Tips​

  • ABI Requirements: Only include the functions/events you need in the ABI
  • Arguments Format: Always provide arguments as a JSON array string
  • Gas Estimation: For write operations, let the node estimate gas unless you have specific requirements
  • Multicall: Use for batch reads to save RPC calls and ensure consistency
  • Event Filtering: Use indexed parameters in events for efficient filtering
  • Simulation: Always simulate complex transactions before executing
  • Block Numbers: For historical queries, be aware of RPC provider's block range limits