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Simulate JSON RPC

Custom JSON RPC method available in Tenderly Web3 Gateway.
The custom RPC methods appear in the tenderly_ namespace.

tenderly_simulateTransaction

Simulates transaction as it would execute on the given block.
PARAMS
  1. 1.
    Transaction Transaction OBJECT
    • from (optional) STRING: hex encoded address
    • to STRING: hex encoded address
    • gas (optional) NUMBER
    • maxFeePerGas (optional) NUMBER max fee: The maximum total fee per gas the sender is willing to pay (includes the network / base fee and miner / priority fee) in wei
    • maxPriorityFeePerGas (optional) NUMBER max priority fee: Maximum fee per gas the sender is willing to pay to miners in wei
    • gasPrice (optional) NUMBER: The gas price willing to be paid by the sender in wei
    • value (optional) NUMBER
    • data (optional) STRING: hex encoded bytes
    • accessList (optional) ARRAY of Access list entry OBJECT
      • address STRING hex encoded address
      • storageKeys ARRAY of STRING representation of 32 byte hex encoded storage key
  2. 2.
    Simulation Block Number (optional) The block number against which transaction should be simulated. Either:
    • STRING Block number
    • ENUM of Block tag earliest|finalized|safe|latest|pending
  3. 3.
    State Overrides (optional) MAP: mapping from an account (address) to override specification
    • key STRING: the account this override applies to
    • value OBJECT: the override specification
      • nonce (optional) STRING: hex encoded 8 byte nonce override for the account
      • code (optional) STRING: data of the code override for the account
      • balance (optional) STRING: hex encoded 32 byte balance override for the account in wei
      • stateDiff (optional) MAP: mapping of storage key to storage value override
        • key STRING: the storage key
        • value STRING: the value override for the given storage key
  4. 4.
    Block Overrides (optional) OBJECT: The set of header fields to override in a block.
    • number (optional) STRING: hex, overrides the block number
    • difficulty (optional) STRING: hex, overrides the block difficulty
    • time (optional) STRING: hex, overrides block timestamp
    • gasLimit (optional) STRING: hex, overrides gas limit
    • coinbase (optional) STRING: hex, overrides block miner
    • random (optional) STRING: hex, overrides the blocks extra data which feeds into the RANDOM opcode
    • baseFee (optional) STRING: hex, overrides block base fee
Raw
cURL
ethers
Response
{
"id": 0,
"jsonrpc": "2.0",
"method": "tenderly_simulateTransaction",
"params": [
{
"from": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
"to": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
"data": "0xa9059cbb00000000000000000000000020a5814b73ef3537c6e099a0d45c798f4bd6e1d60000000000000000000000000000000000000000000000000000000000000001"
},
"0xF4D880"
]
}
​
curl https://mainnet.gateway.tenderly.co \
-X POST \
-H "Content-Type: application/json" \
-d \
'{
"id": 0,
"jsonrpc": "2.0",
"method": "tenderly_simulateTransaction",
"params": [
{
"from": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
"to": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
"data": "0xa9059cbb00000000000000000000000020a5814b73ef3537c6e099a0d45c798f4bd6e1d60000000000000000000000000000000000000000000000000000000000000001"
},
"0xF4D880"
]
}'
​
// Installation Instructions: https://docs.ethers.io/v5/getting-started/#installing
const { ethers } = require("ethers");
​
async function runSimulateTransaction() {
// Initialize an ethers instance
const provider = new ethers.providers.JsonRpcProvider(
"https://goerli.gateway.tenderly.co/$TENDERLY_WEB3_GATEWAY_KEY"
);
​
// Execute method
const result = await provider.send("tenderly_simulateTransaction", [
{
from: "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
to: "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
data: "0xa9059cbb00000000000000000000000020a5814b73ef3537c6e099a0d45c798f4bd6e1d60000000000000000000000000000000000000000000000000000000000000001",
},
"0xF4D880",
]);
​
// Print the output to console
console.log(result);
}
​
(async () => {
runSimulateTransaction();
})();
{
"id": 0,
"jsonrpc": "2.0",
"result": {
"status": true,
"gasUsed": "0xc94e",
"cumulativeGasUsed": "0x0",
"blockNumber": "0x1103aae",
"type": "0x0",
"logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000002000000080000000000000000000000000000000000000000000008000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000010000000000000004000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000000000000000000000000020000000000000000000000000000000000200000800000000000000000000000000000000000000000000000000000",
"logs": [
{
"name": "Transfer",
"anonymous": false,
"inputs": [
{
"value": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
"type": "address",
"name": "src"
},
{
"value": "0x20a5814b73ef3537c6e099a0d45c798f4bd6e1d6",
"type": "address",
"name": "dst"
},
{
"value": "1",
"type": "uint256",
"name": "wad"
}
],
"raw": {
"address": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
"topics": [
"0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
"0x000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045",
"0x00000000000000000000000020a5814b73ef3537c6e099a0d45c798f4bd6e1d6"
],
"data": "0x0000000000000000000000000000000000000000000000000000000000000001"
}
}
],
"trace": [
{
"type": "CALL",
"from": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
"to": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
"gas": "0xbeb6dbc",
"gasUsed": "0x750a",
"value": "0x0",
"input": "0xa9059cbb00000000000000000000000020a5814b73ef3537c6e099a0d45c798f4bd6e1d60000000000000000000000000000000000000000000000000000000000000001",
"decodedInput": [
{
"value": "0x20a5814b73ef3537c6e099a0d45c798f4bd6e1d6",
"type": "address",
"name": "dst"
},
{
"value": "1",
"type": "uint256",
"name": "wad"
}
],
"method": "transfer",
"output": "0x0000000000000000000000000000000000000000000000000000000000000001",
"decodedOutput": [
{
"value": true,
"type": "bool",
"name": ""
}
],
"subtraces": 0,
"traceAddress": [
0
]
}
],
"assetChanges": [
{
"assetInfo": {
"standard": "ERC20",
"type": "Fungible",
"contractAddress": "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
"symbol": "weth",
"name": "WETH",
"logo": "https://assets.coingecko.com/coins/images/2518/large/weth.png?1628852295",
"decimals": 18,
"dollarValue": "1834.6199951171875"
},
"type": "Transfer",
"from": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
"to": "0x20a5814b73ef3537c6e099a0d45c798f4bd6e1d6",
"rawAmount": "0x1",
"amount": "0.000000000000000001",
"dollarValue": "0.0000000000000018346199951171875"
}
],
"balanceChanges": [
{
"address": "0x20a5814b73ef3537c6e099a0d45c798f4bd6e1d6",
"dollarValue": "0.0000000000000018346199951171875",
"transfers": [
0
]
},
{
"address": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
"dollarValue": "-0.0000000000000018346199951171875",
"transfers": [
0
]
}
]
}
}
RESULT: Simulation result OBJECT
  • status NUMBER: either 1 (success) or 0 (failure)
  • gasUsed NUMBER: The amount of gas used by this specific transaction alone
  • cumulativeGasUsed NUMBER: the total amount of gas used when this transaction was executed in the block
  • blockNumber NUMBER: the block number in which this transaction was simulated
  • type NUMBER: transaction type, 0x00 for legacy transactions, 0x01 for access list types, 0x02 for dynamic fees
  • logsBloom STRING: bloom filter for light clients to quickly retrieve related logs
  • logs: an array of emitted events ARRAY of OBJECT
    • name STRING: event name
    • anonymous BOOLEAN: indicates if event is anonymous
    • inputs: array of decoded log arguments ARRAY of decoded logs OBJECT
      • name STRING: event argument name
      • type STRING: event argument type from Solidity type system
      • value (optional) STRING string representation value of the argument; interpret according to the type field
    • raw OBJECT: raw logs
      • address STRING hex encoded address: address of the contract emitting the log
      • topics ARRAY of STRING 32 hex encoded bytes
      • data STRING hex encoded string representing event data
  • trace: Trace ARRAY of OBJECT
    • type STRING type: trace item type - either CALL| CALLCODE| STATICCALL| DELEGATECALL| CREATE| CREATE2| SELFDESTRUCT
    • from STRING: hex encoded address
    • to STRING: hex encoded address
    • gas STRING: hex encoded unsigned 64 byte integer representing event gas
    • gasUsed STRING: hex encoded unsigned 64 byte integer representing event gasUsed
    • value STRING: hex encoded unsigned 64 byte integer representing event value in wei
    • error STRING: low-level error from virtual machine
    • errorReason STRING: extracted error reason in case of revert
    • input STRING: hex encoded string representation of raw input bytes for the trace point
    • method STRING: invoked contract method
    • decodedInput : decoded input for the invoked method - ARRAY of decoded in argument OBJECT
      • value STRING: string representation value of the argument; interpret according to the type field.
      • type STRING: the Solidity type of this argument
      • name STRING: the name of this argument
    • output STRING: raw trace output
    • decodedOutput : decoded output of the invoked method - ARRAY of decoded out argument OBJECT
      • value STRING: string representation value of the argument; interpret according to the type field.
      • type STRING: the Solidity type of this argument
      • name STRING: the name of this argument
    • subtraces NUMBER: number of child traces
    • traceAddress : trace position ARRAY of NUMBER
  • assetChanges ARRAY:
    • type STRING type of asset change, can be transfer, mint, burn
    • from STRING: address of the sender (empty for mint transfers)
    • to STRING: address of the receiver (empty for burn transfers)
    • amount STRING: the amount of the token that was transferred
    • rawAmount STRING: raw amount transfer for the token
    • dollarValueSTRING: dollar value of the transferred token
    • assetInfoOBJECT: asset information
      • standard STRING: supported token standards: ERC20, ERC721, NativeCurrency
      • type STRING: the token type: Native, Fungible, Non-Fungible
      • contractAddressSTRING : address of the contract
      • symbol STRING: token symbol
      • name STRING: token name
      • logo STRING: URL for the token icon
      • decimals NUMBER: number of decimals in the token
      • dollarValueSTRING: dollar value of a single token
  • balanceChanges ARRAY: an array of balance changes - cumulated asset changes
    • address STRING address
    • dollarValue STRING: dollar value of cumulated asset changes
    • transfers ARRAY: array of asset changes indexes
​
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Last modified 1mo ago