Transaction Simulation Explainer

WHAT IT DOES

Transaction Simulation Explainer takes any transaction and runs a dry-run simulation using eth_call against the current blockchain state. It tells you whether the transaction would succeed or fail before you ever sign it. If it fails, it captures the revert reason—whether it's out of gas, insufficient balance, a contract revert, or a custom error. If it succeeds, it explains what the transaction will accomplish. The tool also decodes the function call, extracts parameters, flags risks like ownership changes, approvals, or self-destruct, and provides an AI explanation of the simulation result. You get a clear picture of whether the transaction will work before you spend gas on it.

HOW TO USE

Connect your EVM wallet using the BotGentz wallet bridge. Select the network matching your transaction. Paste a transaction hash to fetch and simulate the full transaction, or paste raw hex call data to simulate it directly. Click "Simulate"—the tool builds a call request using your wallet as the sender (if needed), executes eth_call against the current block state, and captures the result. Results show you whether the transaction would succeed or fail, the failure reason (if any), the decoded function name and parameters, risk flags, and an AI explanation of what the simulation means. No transaction is ever submitted—this is a read-only simulation.

TECHNICAL MECHANISM

The app uses the injected BGWallet bridge to access the EVM provider via ethers.js v5.7.2. It builds a transaction object from the user input or fetched transaction data, including from address (using the connected wallet), to address, data, value, and gasLimit. It then calls provider.call(tx), which executes eth_call against the current block state. This is a dry-run—no state changes occur. If the call succeeds, the result is captured and the simulation is marked as successful. If the call reverts, the error message is parsed for the revert reason using regex patterns to extract custom error messages, "out of gas," "insufficient funds," or the raw revert string. The transaction data is also decoded against a built-in signature database of common functions (transfer, approve, ownerOf, etc.) to display the function name and parameters. Risk flags are generated based on the decoded function and value. The AI bridge (BGAI.generate) receives a prompt with the decoded data, simulation result, and flags, and returns a plain-English explanation.

WHAT IT CANNOT SEE

This tool cannot guarantee that simulation results match actual execution—state can change between simulation and submission. It cannot detect off-chain consequences of a transaction. It cannot simulate complex multi-transaction patterns or cross-contract interactions. It cannot detect front-running or predict if your transaction will be front-run. It cannot verify malicious intent hidden in bytecode. It cannot predict gas price changes or congestion. It does not simulate the transaction with the exact gas limits that would be used in a real submission—gas estimation is separate from simulation.

PLEASE NOTE

Supports EVM-compatible chains only—Ethereum, Sepolia, Polygon, Mumbai, Optimism, Arbitrum, and any network the wallet bridge connects to. Simulations are estimates based on current state—actual execution may differ. Explanations are AI-generated and should be treated as assists, not authoritative guarantees. Always review the transaction details in your wallet's own signature prompt before approving. The wallet's signature step is the only protection that actually gates any action—this tool is informational and does not replace that safeguard. Free to use, no API keys required.