eth_simulateV1 | Hyperliquid EVM

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Parameters

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Simulation parameters

• blockStateCalls (array, required) — Array of block state call objects
  • calls (array, required) — Array of transaction calls to simulate
    • from (string, optional) — Transaction sender address
    • to (string, optional) — Transaction recipient address
    • gas (string, optional) — Gas limit as hexadecimal string
    • gasPrice (string, optional) — Gas price as hexadecimal string
    • value (string, optional) — Transaction value as hexadecimal string
    • data (string, optional) — Transaction data as hexadecimal string
  • blockOverride (object, optional) — Block state override options
    • number (string) — Block number to simulate against (e.g., “latest”)
• traceTransfers (boolean, optional) — Whether to trace token transfers during simulation
• validation (boolean, optional) — Whether to perform validation during simulation

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Response

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Response structure

• result — Object containing simulation outcome data including gas estimates, transaction success status, and any error messages

• Gas consumption estimates and limits
• Transaction success or failure status
• State changes and side effects
• Error messages if simulation fails
• Transfer traces if enabled

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Usage example

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Basic transaction simulation

// Simulate a simple value transfer
const simulateTransaction = async () => {
  const response = await fetch('https://hyperliquid-mainnet.core.chainstack.com/YOUR_ENDPOINT/evm', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      jsonrpc: '2.0',
      method: 'eth_simulateV1',
      params: [{
        blockStateCalls: [{
          calls: [{
            from: "0x69835D480110e4919B7899f465aAB101e21c8A87",
            to: "0xb4DcFE4590adBd275aC3Ef1A3dd10e819d11648c",
            gas: "0x5208",
            gasPrice: "0x9184e72a000",
            value: "0xde0b6b3a7640000",
            data: "0x"
          }],
          blockOverride: {
            number: "latest"
          }
        }],
        traceTransfers: false,
        validation: true
      }],
      id: 1
    })
  });
  
  const data = await response.json();
  return data.result;
};

// Test transaction before sending
simulateTransaction().then(result => {
  console.log('Simulation result:', result);
  // Check if transaction would succeed before actually sending it
});

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Example request

curl -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_simulateV1",
    "params": [
      {
        "blockStateCalls": [
          {
            "calls": [
              {
                "from": "0x69835D480110e4919B7899f465aAB101e21c8A87",
                "to": "0xb4DcFE4590adBd275aC3Ef1A3dd10e819d11648c",
                "gas": "0x5208",
                "gasPrice": "0x9184e72a000",
                "value": "0xde0b6b3a7640000",
                "data": "0x"
              }
            ],
            "blockOverride": {
              "number": "latest"
            }
          }
        ],
        "traceTransfers": false,
        "validation": true
      }
    ],
    "id": 1
  }' \
  https://hyperliquid-mainnet.core.chainstack.com/4f8d8f4040bdacd1577bff8058438274/evm

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Use cases

• Transaction testing: Test transactions before submitting them to avoid failed transactions and wasted gas
• Gas estimation: Accurately estimate gas requirements for complex transactions and smart contract interactions
• Smart contract debugging: Debug smart contract calls and identify potential issues before deployment
• DeFi protocol integration: Test complex DeFi transactions involving multiple protocols and token swaps
• Transaction optimization: Optimize transaction parameters and gas settings for better execution
• Risk management: Assess transaction risks and potential failures in trading and financial applications
• MEV protection: Simulate transactions to detect and prevent MEV (Maximum Extractable Value) attacks
• Batch transaction planning: Plan and validate batch transactions before execution
• State change prediction: Predict state changes and side effects of complex transactions
• Cross-protocol interactions: Test interactions between different protocols and smart contracts
• Governance proposals: Simulate governance proposals and their effects before voting
• Arbitrage strategies: Test arbitrage opportunities and validate profitability before execution
• Liquidation simulations: Test liquidation scenarios and validate liquidation bot strategies
• Oracle integration: Test oracle data integration and price feed reliability
• Bridge operations: Simulate cross-chain bridge operations and validate transfer logic
• Staking mechanisms: Test staking and unstaking operations with various parameters
• Token distribution: Simulate token distribution scenarios and validate allocation logic
• Flash loan strategies: Test flash loan strategies and validate repayment scenarios
• AMM interactions: Simulate automated market maker interactions and liquidity provision
• NFT marketplace: Test NFT trading scenarios and marketplace integrations