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eth_call
The example is a call to the poolinfo of the Gamma MasterChef contract. Optimism API method eth_call executes a smart contract function call directly and returns the result without requiring a transaction or changing the state on the blockchain. This method is widely used for reading data from smart contracts.
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Parameters

  • transactionObject — an object containing transaction parameters, including:
    • to — the address of the contract to call.
    • data — the call data, typically including the function signature and parameters.
  • blockParameter — a string specifying the block number (in hexadecimal) or one of the strings "earliest", "latest", or "pending", indicating the blockchain state to use for the call. Most commonly, "latest" is used.

State override (optional)

eth_call accepts an optional third parameter: a state override set that changes account state for this call only. Nothing is written to the chain. The set is an object keyed by account address, and each address can override:
  • balance — the account balance in wei, hex-encoded
  • nonce — the account nonce, hex-encoded
  • code — the bytecode to run at the address
  • state — storage slot values that replace the account’s entire storage
  • stateDiff — storage slot values to change, keeping the rest of the storage
This example puts bytecode that returns 42 at an unused address, then calls that address:

Response

  • result — the result of the call, encoded as a hexadecimal string. The format of the result depends on the function called.

Use case

The eth_call method is essential for:
  • DApps that need to retrieve state or compute derived values from smart contracts without making a transaction.
  • Wallets and interfaces that display contract information, such as token balances or the state of a decentralized finance (DeFi) contract.
  • Automated scripts and bots that monitor contract states or conditions on the blockchain.

Body

application/json
jsonrpc
string
default:2.0
method
string
default:eth_call
id
integer
default:1
params
(object | string)[]

Response

200 - application/json

The result of the call

jsonrpc
string
id
integer
result
string
Last modified on October 1, 2026