Transaction Simulator

Preview exact transaction outcomes, avoid failed or malicious transactions, and save valuable funds. Simulate the execution of one-off and bundled transactions on major EVM chains.

Use Tenderly’s Simulation RPC to simulate the outcomes of your transactions without deploying them to the blockchain. By simulating transactions before sending them on-chain, you can avoid unexpected failures, detect unwanted consequences, and save valuable resources.

With the Simulation RPC, you can know exactly what’s going to happen with your transactions. Run a transaction simulation to get an overview of the expected asset and balance changes, gas consumption, and other relevant transaction parameters.

Additionally, you can use the Simulation RPC to run both individual, one-off transaction simulations and simulation bundles:
- tenderly_simulateTransaction runs an individual simulation and returns a detailed response.
- tenderly_simulateBundle runs a bundle of interconnected simulations using a single request.

Always send transactions with confidence with Tenderly’s Simulation RPC.

RPC Methods

tenderly_simulateBundle

Simulates a bundle of transactions as it would execute on the given block and returns results for each transaction.

Sample code

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Eth
Ether
Curl

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from web3 import Web3
w3 = Web3(Web3.HTTPProvider("https://YOUR_QUICKNODE_ENDPOINT_HERE.com"))
resp = w3.provider.make_request(
  'tenderly_simulateBundle',
  [[{"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xcfae3217"}, {"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xa4136862000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000116f766f5f6a655f74726163655f74657374000000000000000000000000000000"}, {"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xcfae3217"}], "latest", {}, {}]
)
print(resp)

require 'eth'

client = Eth::Client.create "https://YOUR_QUICKNODE_ENDPOINT_HERE.com"

payload = {
    "id":1,
    "jsonrpc":"2.0",
    "method":"tenderly_simulateBundle",
    "params": [[{"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xcfae3217"}, {"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xa4136862000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000116f766f5f6a655f74726163655f74657374000000000000000000000000000000"}, {"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xcfae3217"}], "latest", {}, {}]
}

response = client.send(payload.to_json)
puts response

const ethers = require("ethers");
(async () : {
  const provider = new ethers.providers.JsonRpcProvider("https://YOUR_QUICKNODE_ENDPOINT_HERE.com");
  const network = await provider.send(
    "tenderly_simulateBundle",
    [[{"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xcfae3217"}, {"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xa4136862000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000116f766f5f6a655f74726163655f74657374000000000000000000000000000000"}, {"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xcfae3217"}], "latest", {}, {}]
  );
  console.log(network);
})();

curl https://YOUR_QUICKNODE_ENDPOINT_HERE.com \
  -X POST \
  -H "Content-Type: application/json" \
  --data '{"method":"tenderly_simulateBundle","params": [[{"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xcfae3217"}, {"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xa4136862000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000116f766f5f6a655f74726163655f74657374000000000000000000000000000000"}, {"to":"0x9e8b680bb76171d3feffbd213c0cb5e150cd17d1", "from":"0x0000000000000000000000000000000000000000", "data":"0xcfae3217"}], "latest", {}, {}],"id":1,"jsonrpc":"2.0"}'

tenderly_simulateTransaction

Simulates transaction as it would execute on the given block.

Sample code

Web3

Web3
Eth
Ether
Curl

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from web3 import Web3
w3 = Web3(Web3.HTTPProvider("https://YOUR_QUICKNODE_ENDPOINT_HERE.com"))
resp = w3.provider.make_request(
  'tenderly_simulateTransaction',
  [{"to":"0x0cda2396c6edc69fe7d47afacac81ce5594640d8", "from":"0xa5b9d8a0b0fa04ba71bdd68069661ed5c0848884", "data":"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"}, "latest", {}, {}]
)
print(resp)

require 'eth'

client = Eth::Client.create "https://YOUR_QUICKNODE_ENDPOINT_HERE.com"

payload = {
    "id":1,
    "jsonrpc":"2.0",
    "method":"tenderly_simulateTransaction",
    "params": [{"to":"0x0cda2396c6edc69fe7d47afacac81ce5594640d8", "from":"0xa5b9d8a0b0fa04ba71bdd68069661ed5c0848884", "data":"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"}, "latest", {}, {}]
}

response = client.send(payload.to_json)
puts response

const ethers = require("ethers");
(async () : {
  const provider = new ethers.providers.JsonRpcProvider("https://YOUR_QUICKNODE_ENDPOINT_HERE.com");
  const network = await provider.send(
    "tenderly_simulateTransaction",
    [{"to":"0x0cda2396c6edc69fe7d47afacac81ce5594640d8", "from":"0xa5b9d8a0b0fa04ba71bdd68069661ed5c0848884", "data":"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"}, "latest", {}, {}]
  );
  console.log(network);
})();

curl https://YOUR_QUICKNODE_ENDPOINT_HERE.com \
  -X POST \
  -H "Content-Type: application/json" \
  --data '{"method":"tenderly_simulateTransaction","params": [{"to":"0x0cda2396c6edc69fe7d47afacac81ce5594640d8", "from":"0xa5b9d8a0b0fa04ba71bdd68069661ed5c0848884", "data":"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"}, "latest", {}, {}],"id":1,"jsonrpc":"2.0"}'

tenderly_estimateGas

Estimate the gas cost of a transaction

Sample code

Web3

Web3
Eth
Ether
Curl

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from web3 import Web3
w3 = Web3(Web3.HTTPProvider("https://YOUR_QUICKNODE_ENDPOINT_HERE.com"))
resp = w3.provider.make_request(
  'tenderly_estimateGas',
  [{"from":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, "latest"]
)
print(resp)

require 'eth'

client = Eth::Client.create "https://YOUR_QUICKNODE_ENDPOINT_HERE.com"

payload = {
    "id":1,
    "jsonrpc":"2.0",
    "method":"tenderly_estimateGas",
    "params": [{"from":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, "latest"]
}

response = client.send(payload.to_json)
puts response

const ethers = require("ethers");
(async () : {
  const provider = new ethers.providers.JsonRpcProvider("https://YOUR_QUICKNODE_ENDPOINT_HERE.com");
  const network = await provider.send(
    "tenderly_estimateGas",
    [{"from":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, "latest"]
  );
  console.log(network);
})();

curl https://YOUR_QUICKNODE_ENDPOINT_HERE.com \
  -X POST \
  -H "Content-Type: application/json" \
  --data '{"method":"tenderly_estimateGas","params": [{"from":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, "latest"],"id":1,"jsonrpc":"2.0"}'

tenderly_estimateGasBundle

Estimate the gas cost of a transaction bundle

Sample code

Web3

Web3
Eth
Ether
Curl

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from web3 import Web3
w3 = Web3(Web3.HTTPProvider("https://YOUR_QUICKNODE_ENDPOINT_HERE.com"))
resp = w3.provider.make_request(
  'tenderly_estimateGasBundle',
  [[{"from":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x23b872dd0000000000000000000000007f39c581f595b53c5cb19bd0b3f8da6c935e2ca00000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000007f39c581f595b53c5cb19bd0b3f8da6c935e2ca00000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "data":"0xea598cb00000000000000000000000000000000000000000000000000c1291a92f17a100"}], "latest"]
)
print(resp)

require 'eth'

client = Eth::Client.create "https://YOUR_QUICKNODE_ENDPOINT_HERE.com"

payload = {
    "id":1,
    "jsonrpc":"2.0",
    "method":"tenderly_estimateGasBundle",
    "params": [[{"from":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x23b872dd0000000000000000000000007f39c581f595b53c5cb19bd0b3f8da6c935e2ca00000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000007f39c581f595b53c5cb19bd0b3f8da6c935e2ca00000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "data":"0xea598cb00000000000000000000000000000000000000000000000000c1291a92f17a100"}], "latest"]
}

response = client.send(payload.to_json)
puts response

const ethers = require("ethers");
(async () : {
  const provider = new ethers.providers.JsonRpcProvider("https://YOUR_QUICKNODE_ENDPOINT_HERE.com");
  const network = await provider.send(
    "tenderly_estimateGasBundle",
    [[{"from":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x23b872dd0000000000000000000000007f39c581f595b53c5cb19bd0b3f8da6c935e2ca00000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000007f39c581f595b53c5cb19bd0b3f8da6c935e2ca00000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "data":"0xea598cb00000000000000000000000000000000000000000000000000c1291a92f17a100"}], "latest"]
  );
  console.log(network);
})();

curl https://YOUR_QUICKNODE_ENDPOINT_HERE.com \
  -X POST \
  -H "Content-Type: application/json" \
  --data '{"method":"tenderly_estimateGasBundle","params": [[{"from":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x23b872dd0000000000000000000000007f39c581f595b53c5cb19bd0b3f8da6c935e2ca00000000000000000000000009008d19f58aabd9ed0d60971565aa8510560ab410000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0xae7ab96520DE3A18E5e111B5EaAb095312D7fE84", "data":"0x095ea7b30000000000000000000000007f39c581f595b53c5cb19bd0b3f8da6c935e2ca00000000000000000000000000000000000000000000000000c1291a92f17a100"}, {"from":"0x9008D19f58AAbD9eD0D60971565AA8510560ab41", "to":"0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", "data":"0xea598cb00000000000000000000000000000000000000000000000000c1291a92f17a100"}], "latest"],"id":1,"jsonrpc":"2.0"}'

This add-on is currently in Beta

Supported Chains

RPC Methods

Supported Chains

Plans & features

Transaction Simulator

This add-on is currently in Beta

Supported Chains

RPC Methods

Supported Chains

Plans & features

Contact our sales team

Contact our sales team