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POST
/
efb0a5eccd2caa5135eb54eba6f7f300
eth_callMany
curl --request POST \
  --url https://optimism-mainnet.core.chainstack.com/efb0a5eccd2caa5135eb54eba6f7f300 \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "method": "eth_callMany",
  "id": 1,
  "params": [
    [
      {
        "transactions": [
          {
            "from": "0xacD03D601e5bB1B275Bb94076fF46ED9D753435A",
            "to": "0x94b008aA00579c1307B0EF2c499aD98a8ce58e58",
            "gas": "0xf4240",
            "gasPrice": "0x7896e72a",
            "data": "0xa9059cbb000000000000000000000000bc0E63965946815d105E7591407704e6e1964E590000000000000000000000000000000000000000000000000000000005f5e100"
          },
          {
            "to": "0x94b008aA00579c1307B0EF2c499aD98a8ce58e58",
            "gasPrice": "0x7896e72a",
            "data": "0x70a08231000000000000000000000000bc0E63965946815d105E7591407704e6e1964E59"
          }
        ],
        "blockOverride": {
          "blockNumber": "0x6eee101"
        }
      }
    ],
    {
      "blockNumber": "0x6eee101",
      "transactionIndex": 1
    },
    {}
  ]
}
'
{
  "jsonrpc": "<string>",
  "id": 123,
  "result": [
    {}
  ]
}

Documentation Index

Fetch the complete documentation index at: https://docs.chainstack.com/llms.txt

Use this file to discover all available pages before exploring further.

Optimism API method eth_callMany executes a list of transaction bundles without creating transactions on the blockchain. This method is particularly useful for simulating transactions to understand their potential outcomes. It supports simulating transactions at an intermediate state of a block, simulating multiple transactions with sequential dependencies, and overwriting block headers. This examples simulates the transfer of 100 USDT to an address in block 116318465 at transaction position 1 in the block and does the balance check of the address for the USDT, all in one call.
When called against a block older than the latest ~128 blocks, this method is treated as an archive request (2 RUs instead of 1 RU). See request units.
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​
Parameters

  • BUNDLES (array, required): A list of bundles where each bundle contains:
    • transactions (array): An array of transaction objects with parameters similar to eth_call.
    • blockOverride (object, optional): Overrides for the execution context block header, including blockNumber, blockHash, coinbase, timestamp, difficulty, gasLimit, and baseFee.
  • SIMULATION CONTEXT (object, required): The context for the simulation, specifying the blockNumber or Tag and transactionIndex.
  • STATE OVERRIDES (object, optional): An optional mapping for state overrides, following the eth_call standard.
  • TIMEOUT (integer, optional): The maximum running time for the simulations in milliseconds, defaulting to 5000 milliseconds.

​
Response

The method returns a list of lists containing either the return value of the executed contract call or the reverted error code.
  • array - All the return/error values
    • value - The value if was successful
    • error - The error if the transaction failed

​
Use case

The eth_callMany method is essential for:
  • Developers who need to simulate the outcome of transactions at a specific block height without making actual state changes.
  • Applications that require understanding the sequential dependencies between multiple transactions.
  • Services that need to test the impact of block header changes on transaction execution.

Body

application/json
​
jsonrpc
string
default:2.0
required
​
method
string
default:eth_callMany
required
​
id
integer
default:1
required
​
params
object[]
required

Response

200 - application/json

The result of the multiple calls

​
jsonrpc
string
​
id
integer
​
result
object[]

The results of the executed calls.

Last modified on May 1, 2026