/v4/data/security/transaction/simulate

60000 credits per API call

Simulate a transaction against live chain state before signing or broadcasting it. The simulation returns balance movements, execution steps, and a risk assessment covering drainer patterns, suspicious approvals, delegatecalls, MEV exposure, and other threat heuristics.

Input modes — provide either:

• from (plus optional to, value, data, nonce, fees) — simulate an unsigned transaction, or
• rawTx — replay a signed, already-mined transaction. The transaction is looked up on-chain, so it must exist; to replay it accurately pass blockNumber = the block before it was mined.

Requests with neither from nor rawTx return 400.

RPC — ethereum-mainnet, bsc-mainnet, polygon-mainnet, and base-mainnet have built-in RPC support. For any other supported chain, pass your own rpcUrl.

Other notes

• blockNumber and gasLimit are JSON numbers; value, nonce, and the fee fields are decimal or hex strings (values can exceed the safe JavaScript integer range).
• gasLimit defaults to 30,000,000 — lower it on chains with a smaller block gas limit (e.g. Gnosis).
• The risk summary (score, level, title, steps, warnings, risks) is returned at the top level of the response.

{
  "chain": "ethereum-mainnet",
  "from": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
  "to": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
  "value": "0"
}

{
  "success": true,
  "score": 45,
  "level": "medium",
  "title": "Transaction executes 1 step(s) with 2 warning(s)",
  "risks": [
    {
      "name": "Suspicious approvals",
      "weight": 25,
      "detected": true,
      "description": "High-value token approvals detected"
    }
  ],
  "gas_used": 55690
}