> ## 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. # eth_simulateV1 | Arc > Arc API method that simulates transaction execution. eth_simulateV1 JSON-RPC method available on the Arc blockchain via Chainstack. Arc API method that simulates transaction execution. ## Parameters * `object` — the simulation configuration object * `quantity or tag` — the block number in hex format or block tag (`latest`, `earliest`, `pending`, `safe`, `finalized`) ## Response * `object` — the simulation result ## Example: simulate a USDC transfer The code examples on this page simulate a transfer of 1 USDC from `0x5d20879655df3c1e04ab111af0009ad650e762f0` to `0x000000000000000000000000000000000000dEaD` through the USDC ERC-20 interface at `0x3600000000000000000000000000000000000000`. The `stateOverrides` entry sets the sender's balance to 10 USDC (`0x8ac7230489e80000` in the 18-decimal native unit) for the simulation only, so the result does not depend on the account's live balance. The simulated call returns `true` in `returnData` and two `Transfer` logs for the same movement: * The [EIP-7708](https://eips.ethereum.org/EIPS/eip-7708) native-value log emitted by the system address `0xfffffffffffffffffffffffffffffffffffffffe`, with the amount `1000000000000000000` in 18 decimals. * The ERC-20 `Transfer` event emitted by `0x3600000000000000000000000000000000000000`, with the amount `1000000` in 6 decimals. ## `eth_simulateV1` code examples ```javascript ethers.js theme={"system"} const { JsonRpcProvider } = require("ethers"); const provider = new JsonRpcProvider("CHAINSTACK_NODE_URL"); async function call() { const result = await provider.send("eth_simulateV1", [{"blockStateCalls": [{"stateOverrides": {"0x5d20879655df3c1e04ab111af0009ad650e762f0": {"balance": "0x8ac7230489e80000"}}, "calls": [{"from": "0x5d20879655df3c1e04ab111af0009ad650e762f0", "to": "0x3600000000000000000000000000000000000000", "data": "0xa9059cbb000000000000000000000000000000000000000000000000000000000000dead00000000000000000000000000000000000000000000000000000000000f4240"}]}]}, "latest"]); console.log(result); } call(); ``` ```python web3.py theme={"system"} from web3 import Web3 node_url = "CHAINSTACK_NODE_URL" web3 = Web3(Web3.HTTPProvider(node_url)) sender = "0x5d20879655df3c1e04ab111af0009ad650e762f0" usdc = "0x3600000000000000000000000000000000000000" transfer_data = "0xa9059cbb000000000000000000000000000000000000000000000000000000000000dead00000000000000000000000000000000000000000000000000000000000f4240" result = web3.provider.make_request("eth_simulateV1", [ { "blockStateCalls": [ { "stateOverrides": {sender: {"balance": "0x8ac7230489e80000"}}, "calls": [{"from": sender, "to": usdc, "data": transfer_data}] } ] }, "latest" ]) print(result) ``` ```shell cURL theme={"system"} curl -X POST "CHAINSTACK_NODE_URL" \ -H "Content-Type: application/json" \ --data '{ "jsonrpc": "2.0", "method": "eth_simulateV1", "params": [{"blockStateCalls": [{"stateOverrides": {"0x5d20879655df3c1e04ab111af0009ad650e762f0": {"balance": "0x8ac7230489e80000"}}, "calls": [{"from": "0x5d20879655df3c1e04ab111af0009ad650e762f0", "to": "0x3600000000000000000000000000000000000000", "data": "0xa9059cbb000000000000000000000000000000000000000000000000000000000000dead00000000000000000000000000000000000000000000000000000000000f4240"}]}]}, "latest"], "id": 1 }' ``` ## OpenAPI ````yaml openapi/arc_node_api/execute_transactions/eth_simulateV1.json POST / openapi: 3.0.0 info: title: Chainstack Node API version: 1.0.0 description: This is an API for interacting with a Chainstack node. servers: - url: https://arc-testnet.core.chainstack.com/6caa7fd90475ac9214f7521dd460fa7c security: [] paths: /: post: tags: - upload summary: eth_simulateV1 operationId: eth_simulateV1 requestBody: required: true content: application/json: schema: type: object properties: id: type: integer default: 1 jsonrpc: type: string default: '2.0' method: type: string default: eth_simulateV1 params: type: array default: - blockStateCalls: - stateOverrides: '0x5d20879655df3c1e04ab111af0009ad650e762f0': balance: '0x8ac7230489e80000' calls: - from: '0x5d20879655df3c1e04ab111af0009ad650e762f0' to: '0x3600000000000000000000000000000000000000' data: >- 0xa9059cbb000000000000000000000000000000000000000000000000000000000000dead00000000000000000000000000000000000000000000000000000000000f4240 - latest items: anyOf: - type: object title: Simulation config description: The simulation configuration. - type: string title: Block description: Block number or tag (latest, earliest, pending). responses: '200': description: Returns the result of eth_simulateV1. content: application/json: schema: type: object properties: jsonrpc: type: string id: type: integer result: type: array items: type: object properties: hash: type: string parentHash: type: string sha3Uncles: type: string miner: type: string stateRoot: type: string transactionsRoot: type: string receiptsRoot: type: string logsBloom: type: string difficulty: type: string number: type: string gasLimit: type: string gasUsed: type: string timestamp: type: string extraData: type: string mixHash: type: string nonce: type: string baseFeePerGas: type: string withdrawalsRoot: type: string blobGasUsed: type: string excessBlobGas: type: string parentBeaconBlockRoot: type: string requestsHash: type: string size: type: string uncles: type: array items: type: object transactions: type: array items: type: string withdrawals: type: array items: type: object calls: type: array items: type: object properties: returnData: type: string logs: type: array items: type: object gasUsed: type: string status: type: string error: type: object properties: code: type: integer message: type: string example: jsonrpc: '2.0' id: 1 result: - hash: >- 0x435b7fef1c605c6bdcae29cc8884ea42468a355535e754f3c8a383b88e27af18 parentHash: >- 0x413c02f646afc1c57bb629dc2bce46d087045fe1b4883cb4010feb53a992ec23 sha3Uncles: >- 0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347 miner: '0xa693cc18aa09d33dd388013b7a02e5ff863b8760' stateRoot: >- 0x0000000000000000000000000000000000000000000000000000000000000000 transactionsRoot: >- 0xcf13e718e73ee2a7f54c5f3a4dcd5c31fd7b75978063508ef18eff6f3cd721eb receiptsRoot: >- 0x313b645e20f7bf16759f997f94a5f757d6ffdbf4deada5ed31b7f53be1369c24 logsBloom: >- 0x00000000000050000000000004000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000000000000008000000000100000000000000000000000000000000000000000000002000000000000000000000000000000000000010000000400000000000000000000004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000402000000000008000000000000000000000000004000000000000000400000000000000000000000000000000000000000000000000000000000000000 difficulty: '0x0' number: '0x3d3a7b9' gasLimit: '0x1c9c380' gasUsed: '0xbe5e' timestamp: '0x6ab88757' extraData: 0x mixHash: >- 0x0000000000000000000000000000000000000000000000000000000000000000 nonce: '0x0000000000000000' baseFeePerGas: '0x0' withdrawalsRoot: >- 0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421 blobGasUsed: '0x0' excessBlobGas: '0x0' parentBeaconBlockRoot: >- 0x5c823ccdb1a7f01536b5a6fd7ae1b424e916246ef717b42f7059f1ce84146dd4 requestsHash: >- 0xe3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 size: '0x2de' uncles: [] transactions: - >- 0xd2cf7abdbedcd933d20056c9fed448ade05caa6ed4c273135ae584026cc3c1f9 withdrawals: [] calls: - returnData: >- 0x0000000000000000000000000000000000000000000000000000000000000001 logs: - address: '0xfffffffffffffffffffffffffffffffffffffffe' topics: - >- 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef - >- 0x0000000000000000000000005d20879655df3c1e04ab111af0009ad650e762f0 - >- 0x000000000000000000000000000000000000000000000000000000000000dead data: >- 0x0000000000000000000000000000000000000000000000000de0b6b3a7640000 blockHash: >- 0x435b7fef1c605c6bdcae29cc8884ea42468a355535e754f3c8a383b88e27af18 blockNumber: '0x3d3a7b9' blockTimestamp: '0x6ab88757' transactionHash: >- 0xd2cf7abdbedcd933d20056c9fed448ade05caa6ed4c273135ae584026cc3c1f9 transactionIndex: '0x0' logIndex: '0x0' removed: false - address: '0x3600000000000000000000000000000000000000' topics: - >- 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef - >- 0x0000000000000000000000005d20879655df3c1e04ab111af0009ad650e762f0 - >- 0x000000000000000000000000000000000000000000000000000000000000dead data: >- 0x00000000000000000000000000000000000000000000000000000000000f4240 blockHash: >- 0x435b7fef1c605c6bdcae29cc8884ea42468a355535e754f3c8a383b88e27af18 blockNumber: '0x3d3a7b9' blockTimestamp: '0x6ab88757' transactionHash: >- 0xd2cf7abdbedcd933d20056c9fed448ade05caa6ed4c273135ae584026cc3c1f9 transactionIndex: '0x0' logIndex: '0x1' removed: false gasUsed: '0xbe5e' status: '0x1' ````