# Transaction Simulation API

See exactly what a transaction will do—*before* it’s signed. Our API runs a full on‑chain simulation and returns clear, USD‑denominated balance changes, so users of custodial platform such as [Cobo](https://www.cobo.com/) and [Fireblocks](https://www.fireblocks.com/) can approve or reject transfers with confidence.

**Why it matters**

* **Pre‑sign insights** – Know the outcome of any transaction in advance.
* **Seamless integration** – A lightweight REST endpoint that drops straight into your existing workflow.
* **Actionable data** – Balance deltas presented in familiar USD terms.

**Supported chains**\
Ethereum · BNB Smart Chain · Base · Optimism · Polygon · Story · Story Aeneid Testnet

**Get started**\
[Fill out the form](https://blocksec.com/expert-contact) to receive your API key and start simulating in minutes.

## Balance Change

## Raw Transaction Simulation

> Simulate raw transaction and get balance changes

```json
{"openapi":"3.0.3","info":{"title":"Transaction Simulation API","version":"1.0.3"},"servers":[{"url":"https://api.blocksec.com/simulation/v1"}],"paths":{"/raw/balancechange":{"post":{"summary":"Raw Transaction Simulation","description":"Simulate raw transaction and get balance changes","parameters":[{"name":"API-Key","in":"header","required":true,"schema":{"type":"string"}}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/RawTransactionRequest"}}}},"responses":{"200":{"description":"Simulation result","content":{"application/json":{"schema":{"$ref":"#/components/schemas/SimulationResponse"}}}}}}}},"components":{"schemas":{"RawTransactionRequest":{"type":"object","required":["blockNumber","transaction"],"properties":{"blockNumber":{"type":"integer","format":"uint64","description":"The block number on which the transaction simulation is based. If this value is 0, transaction simulation will be based on the latest block."},"transaction":{"type":"string","description":"Raw transaction hex string"},"enableCodeOverwrite":{"type":"boolean","description":"Enable Safe-signature-bypass for the simulation. Defaults to false."},"overwriteAddresses":{"type":"array","items":{"type":"string"},"description":"Addresses on which Safe-signature-bypass should be applied. Only used when enableCodeOverwrite is true. Duplicates are ignored. If omitted or empty, falls back to the top-level `tx.to` decoded from the raw transaction; for contract-creation transactions nothing is applied."}}},"SimulationResponse":{"type":"object","required":["code","message","data"],"properties":{"code":{"type":"integer","format":"int32","enum":[0,1,2,3,4,5,6,7,8],"description":"Status codes:\n- 0: Success\n- 1: Unexpected error (contact phalcon_support@blocksec.com)\n- 2: Invalid request body format\n- 3: Invalid raw transaction\n- 4: Unsupported chain ID\n- 5: Chain-gateway error (contact phalcon_support@blocksec.com)\n- 6: RPC node error (contact phalcon_support@blocksec.com)\n- 7: Invalid chain ID\n- 8: The check of transaction simulation failed\n"},"message":{"type":"string","description":"Human-readable description of the status code"},"data":{"$ref":"#/components/schemas/TransactionData"}}},"TransactionData":{"type":"object","required":["status","blockNumber","txnHash","sender","receiver","timestamp","callData","gasLimit","gasPrice","gasUsed","baseFee","transactionFee","nonce","value","errorInfo","balanceChanges","viewLink"],"properties":{"status":{"type":"boolean","description":"Transaction execution status (true/false)"},"blockNumber":{"type":"integer","format":"uint64","description":"Block number"},"txnHash":{"type":"string","description":"Transaction hash"},"sender":{"type":"string","description":"Transaction initiator address"},"receiver":{"type":"string","description":"Transaction recipient address"},"timestamp":{"type":"string","format":"date-time","description":"Transaction timestamp"},"callData":{"type":"string","description":"Transaction calldata in hex format"},"gasLimit":{"type":"integer","format":"uint64","description":"Maximum gas allowed for transaction"},"gasPrice":{"type":"string","pattern":"^\\d+$","description":"Gas price in wei (as integer string)"},"gasUsed":{"type":"integer","format":"uint64","description":"Actual gas used in the transaction"},"baseFee":{"type":"string","pattern":"^\\d+$","description":"Base fee for EIP-1559 transactions in wei (as integer string)"},"transactionFee":{"type":"string","pattern":"^\\d+$","description":"Total transaction fee in wei (as integer string)"},"nonce":{"type":"integer","format":"uint64","description":"Sender's nonce (equal to number of transactions sent by sender)"},"value":{"type":"string","pattern":"^\\d+$","description":"Transaction value in wei (as integer string)"},"errorInfo":{"type":"string","description":"Error information when status is false"},"balanceChanges":{"type":"array","items":{"$ref":"#/components/schemas/BalanceChange"},"description":"List of account balance changes"},"viewLink":{"type":"string","description":"Phalcon Explorer view link for the transaction simulation"}}},"BalanceChange":{"type":"object","required":["account","assets"],"properties":{"account":{"type":"string","description":"Account address (asset holder)"},"assets":{"type":"array","items":{"$ref":"#/components/schemas/Asset"},"description":"List of asset changes"}}},"Asset":{"type":"object","required":["address","tokenId","rawAmount","amount","iconUrl","isERC1155","isERC721","sign","value"],"properties":{"address":{"type":"string","description":"Token contract address"},"tokenId":{"type":"string","description":"Token ID for ERC721/ERC1155 (empty string for ERC20)"},"rawAmount":{"type":"string","pattern":"^\\d+$","description":"Raw amount (unprocessed by decimals) as integer string"},"amount":{"type":"string","description":"Formatted amount (rawAmount / 10^decimals), empty if decimals missing"},"iconUrl":{"type":"string","description":"URL for token icon (empty if unavailable)"},"isERC1155":{"type":"boolean","description":"Indicates ERC1155 token"},"isERC721":{"type":"boolean","description":"Indicates ERC721 token"},"sign":{"type":"boolean","description":"Indicates sign of rawAmount/amount (positive/negative)"},"value":{"type":"string","description":"USD value of asset in decimal format.\nEmpty if missing token price or decimals information.\nExamples: \n- \"22.94604\" (with USD value)\n- \"\" (no pricing data)\n"}}}}}}
```

## Custom Transaction Simulation

> Simulate custom transaction parameters and get balance changes

```json
{"openapi":"3.0.3","info":{"title":"Transaction Simulation API","version":"1.0.3"},"servers":[{"url":"https://api.blocksec.com/simulation/v1"}],"paths":{"/custom/balancechange":{"post":{"summary":"Custom Transaction Simulation","description":"Simulate custom transaction parameters and get balance changes","parameters":[{"name":"API-Key","in":"header","required":true,"schema":{"type":"string"}}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/CustomTransactionRequest"}}}},"responses":{"200":{"description":"Simulation result","content":{"application/json":{"schema":{"$ref":"#/components/schemas/SimulationResponse"}}}}}}}},"components":{"schemas":{"CustomTransactionRequest":{"type":"object","required":["chainId","transaction"],"properties":{"chainId":{"type":"integer","format":"uint64","description":"Chain ID for the transaction"},"blockNumber":{"type":"integer","format":"uint64","description":"The block number on which the transaction simulation is based. If this value is 0, transaction simulation will be based on the latest block."},"transaction":{"type":"object","required":["sender","receiver","gasLimit","gasPrice","value","input"],"properties":{"sender":{"type":"string","description":"Transaction sender address"},"receiver":{"type":"string","description":"Transaction recipient address"},"gasLimit":{"type":"integer","format":"uint64","description":"Maximum gas allowed for transaction.  If this value is zero, then the simulation will be based on the gasLimit returned by eth_estimateGas."},"gasPrice":{"type":"string","pattern":"^\\d+$","description":"Gas price in wei (as integer string). If this value is zero, then the simulation will be based on the gasPrice returned by eth_gasPrice."},"value":{"type":"string","pattern":"^\\d+$","description":"Transaction value in wei (as integer string)"},"input":{"type":"string","description":"Transaction calldata in hex format"}}},"enableCodeOverwrite":{"type":"boolean","description":"Enable Safe-signature-bypass for the simulation. Defaults to false."},"overwriteAddresses":{"type":"array","items":{"type":"string"},"description":"Addresses on which Safe-signature-bypass should be applied. Only used when enableCodeOverwrite is true. Duplicates are ignored. If omitted or empty, falls back to transaction.receiver."}}},"SimulationResponse":{"type":"object","required":["code","message","data"],"properties":{"code":{"type":"integer","format":"int32","enum":[0,1,2,3,4,5,6,7,8],"description":"Status codes:\n- 0: Success\n- 1: Unexpected error (contact phalcon_support@blocksec.com)\n- 2: Invalid request body format\n- 3: Invalid raw transaction\n- 4: Unsupported chain ID\n- 5: Chain-gateway error (contact phalcon_support@blocksec.com)\n- 6: RPC node error (contact phalcon_support@blocksec.com)\n- 7: Invalid chain ID\n- 8: The check of transaction simulation failed\n"},"message":{"type":"string","description":"Human-readable description of the status code"},"data":{"$ref":"#/components/schemas/TransactionData"}}},"TransactionData":{"type":"object","required":["status","blockNumber","txnHash","sender","receiver","timestamp","callData","gasLimit","gasPrice","gasUsed","baseFee","transactionFee","nonce","value","errorInfo","balanceChanges","viewLink"],"properties":{"status":{"type":"boolean","description":"Transaction execution status (true/false)"},"blockNumber":{"type":"integer","format":"uint64","description":"Block number"},"txnHash":{"type":"string","description":"Transaction hash"},"sender":{"type":"string","description":"Transaction initiator address"},"receiver":{"type":"string","description":"Transaction recipient address"},"timestamp":{"type":"string","format":"date-time","description":"Transaction timestamp"},"callData":{"type":"string","description":"Transaction calldata in hex format"},"gasLimit":{"type":"integer","format":"uint64","description":"Maximum gas allowed for transaction"},"gasPrice":{"type":"string","pattern":"^\\d+$","description":"Gas price in wei (as integer string)"},"gasUsed":{"type":"integer","format":"uint64","description":"Actual gas used in the transaction"},"baseFee":{"type":"string","pattern":"^\\d+$","description":"Base fee for EIP-1559 transactions in wei (as integer string)"},"transactionFee":{"type":"string","pattern":"^\\d+$","description":"Total transaction fee in wei (as integer string)"},"nonce":{"type":"integer","format":"uint64","description":"Sender's nonce (equal to number of transactions sent by sender)"},"value":{"type":"string","pattern":"^\\d+$","description":"Transaction value in wei (as integer string)"},"errorInfo":{"type":"string","description":"Error information when status is false"},"balanceChanges":{"type":"array","items":{"$ref":"#/components/schemas/BalanceChange"},"description":"List of account balance changes"},"viewLink":{"type":"string","description":"Phalcon Explorer view link for the transaction simulation"}}},"BalanceChange":{"type":"object","required":["account","assets"],"properties":{"account":{"type":"string","description":"Account address (asset holder)"},"assets":{"type":"array","items":{"$ref":"#/components/schemas/Asset"},"description":"List of asset changes"}}},"Asset":{"type":"object","required":["address","tokenId","rawAmount","amount","iconUrl","isERC1155","isERC721","sign","value"],"properties":{"address":{"type":"string","description":"Token contract address"},"tokenId":{"type":"string","description":"Token ID for ERC721/ERC1155 (empty string for ERC20)"},"rawAmount":{"type":"string","pattern":"^\\d+$","description":"Raw amount (unprocessed by decimals) as integer string"},"amount":{"type":"string","description":"Formatted amount (rawAmount / 10^decimals), empty if decimals missing"},"iconUrl":{"type":"string","description":"URL for token icon (empty if unavailable)"},"isERC1155":{"type":"boolean","description":"Indicates ERC1155 token"},"isERC721":{"type":"boolean","description":"Indicates ERC721 token"},"sign":{"type":"boolean","description":"Indicates sign of rawAmount/amount (positive/negative)"},"value":{"type":"string","description":"USD value of asset in decimal format.\nEmpty if missing token price or decimals information.\nExamples: \n- \"22.94604\" (with USD value)\n- \"\" (no pricing data)\n"}}}}}}
```

## Trace

## Raw Transaction Simulation

> Simulate raw transaction and return execution trace

```json
{"openapi":"3.0.3","info":{"title":"Transaction Simulation API","version":"1.0.3"},"servers":[{"url":"https://api.blocksec.com/simulation/v1"}],"paths":{"/raw/trace":{"post":{"summary":"Raw Transaction Simulation","description":"Simulate raw transaction and return execution trace","parameters":[{"name":"API-Key","in":"header","required":true,"schema":{"type":"string"}}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/RawTransactionRequest"}}}},"responses":{"200":{"description":"Simulation result with trace","content":{"application/json":{"schema":{"$ref":"#/components/schemas/SimulationTraceResponse"}}}}}}}},"components":{"schemas":{"RawTransactionRequest":{"type":"object","required":["blockNumber","transaction"],"properties":{"blockNumber":{"type":"integer","format":"uint64","description":"The block number on which the transaction simulation is based. If this value is 0, transaction simulation will be based on the latest block."},"transaction":{"type":"string","description":"Raw transaction hex string"},"enableCodeOverwrite":{"type":"boolean","description":"Enable Safe-signature-bypass for the simulation. Defaults to false."},"overwriteAddresses":{"type":"array","items":{"type":"string"},"description":"Addresses on which Safe-signature-bypass should be applied. Only used when enableCodeOverwrite is true. Duplicates are ignored. If omitted or empty, falls back to the top-level `tx.to` decoded from the raw transaction; for contract-creation transactions nothing is applied."}}},"SimulationTraceResponse":{"type":"object","required":["code","message","data"],"properties":{"code":{"type":"integer","format":"int32"},"message":{"type":"string"},"data":{"$ref":"#/components/schemas/TransactionTraceData"}}},"TransactionTraceData":{"allOf":[{"$ref":"#/components/schemas/TransactionData"},{"type":"object","properties":{"trace":{"$ref":"#/components/schemas/Call"}},"required":["trace"]}]},"TransactionData":{"type":"object","required":["status","blockNumber","txnHash","sender","receiver","timestamp","callData","gasLimit","gasPrice","gasUsed","baseFee","transactionFee","nonce","value","errorInfo","balanceChanges","viewLink"],"properties":{"status":{"type":"boolean","description":"Transaction execution status (true/false)"},"blockNumber":{"type":"integer","format":"uint64","description":"Block number"},"txnHash":{"type":"string","description":"Transaction hash"},"sender":{"type":"string","description":"Transaction initiator address"},"receiver":{"type":"string","description":"Transaction recipient address"},"timestamp":{"type":"string","format":"date-time","description":"Transaction timestamp"},"callData":{"type":"string","description":"Transaction calldata in hex format"},"gasLimit":{"type":"integer","format":"uint64","description":"Maximum gas allowed for transaction"},"gasPrice":{"type":"string","pattern":"^\\d+$","description":"Gas price in wei (as integer string)"},"gasUsed":{"type":"integer","format":"uint64","description":"Actual gas used in the transaction"},"baseFee":{"type":"string","pattern":"^\\d+$","description":"Base fee for EIP-1559 transactions in wei (as integer string)"},"transactionFee":{"type":"string","pattern":"^\\d+$","description":"Total transaction fee in wei (as integer string)"},"nonce":{"type":"integer","format":"uint64","description":"Sender's nonce (equal to number of transactions sent by sender)"},"value":{"type":"string","pattern":"^\\d+$","description":"Transaction value in wei (as integer string)"},"errorInfo":{"type":"string","description":"Error information when status is false"},"balanceChanges":{"type":"array","items":{"$ref":"#/components/schemas/BalanceChange"},"description":"List of account balance changes"},"viewLink":{"type":"string","description":"Phalcon Explorer view link for the transaction simulation"}}},"BalanceChange":{"type":"object","required":["account","assets"],"properties":{"account":{"type":"string","description":"Account address (asset holder)"},"assets":{"type":"array","items":{"$ref":"#/components/schemas/Asset"},"description":"List of asset changes"}}},"Asset":{"type":"object","required":["address","tokenId","rawAmount","amount","iconUrl","isERC1155","isERC721","sign","value"],"properties":{"address":{"type":"string","description":"Token contract address"},"tokenId":{"type":"string","description":"Token ID for ERC721/ERC1155 (empty string for ERC20)"},"rawAmount":{"type":"string","pattern":"^\\d+$","description":"Raw amount (unprocessed by decimals) as integer string"},"amount":{"type":"string","description":"Formatted amount (rawAmount / 10^decimals), empty if decimals missing"},"iconUrl":{"type":"string","description":"URL for token icon (empty if unavailable)"},"isERC1155":{"type":"boolean","description":"Indicates ERC1155 token"},"isERC721":{"type":"boolean","description":"Indicates ERC721 token"},"sign":{"type":"boolean","description":"Indicates sign of rawAmount/amount (positive/negative)"},"value":{"type":"string","description":"USD value of asset in decimal format.\nEmpty if missing token price or decimals information.\nExamples: \n- \"22.94604\" (with USD value)\n- \"\" (no pricing data)\n"}}},"Call":{"type":"object","description":"Represents a single EVM execution step, including nested calls and logs.","properties":{"id":{"type":"integer","description":"Represents the execution order of the transaction."},"status":{"type":"boolean","description":"Execution status of the call (true if successful, false otherwise)."},"error":{"type":"string","description":"Error message when the call failed (empty if successful)."},"type":{"type":"string","description":"Type of call (e.g., CALL, DELEGATECALL, STATICCALL, CREATE, CREATE2)."},"from":{"type":"string","description":"Address of the caller (sender of this call)."},"to":{"type":"string","description":"Address of the callee (recipient of this call)."},"value":{"type":"string","description":"ETH value (in wei) transferred in this call."},"input":{"type":"string","description":"Input calldata (hex-encoded) provided to this call."},"output":{"type":"string","description":"Return data (hex-encoded) produced by this call."},"gasLimit":{"type":"integer","format":"uint64","description":"Gas provided for this call."},"gasUsed":{"type":"integer","format":"uint64","description":"Actual gas consumed by this call."},"calls":{"type":"array","description":"Nested sub-calls triggered during this call.","items":{"$ref":"#/components/schemas/Call"}},"logs":{"type":"array","description":"Logs emitted during this call.","items":{"$ref":"#/components/schemas/Log"}}}},"Log":{"type":"object","description":"Represents an Ethereum log event emitted during execution.","properties":{"id":{"type":"integer","description":"Represents the execution order of the transaction."},"address":{"type":"string","description":"Address of the contract that emitted the log."},"topics":{"type":"array","items":{"type":"string"},"description":"Indexed event topics (up to 4), hex-encoded."},"data":{"type":"string","description":"Non-indexed event data payload (hex-encoded)."}}}}}}
```

## Custom Transaction Simulation

> Simulate custom transaction parameters and return execution trace

```json
{"openapi":"3.0.3","info":{"title":"Transaction Simulation API","version":"1.0.3"},"servers":[{"url":"https://api.blocksec.com/simulation/v1"}],"paths":{"/custom/trace":{"post":{"summary":"Custom Transaction Simulation","description":"Simulate custom transaction parameters and return execution trace","parameters":[{"name":"API-Key","in":"header","required":true,"schema":{"type":"string"}}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"#/components/schemas/CustomTransactionRequest"}}}},"responses":{"200":{"description":"Simulation result","content":{"application/json":{"schema":{"$ref":"#/components/schemas/SimulationTraceResponse"}}}}}}}},"components":{"schemas":{"CustomTransactionRequest":{"type":"object","required":["chainId","transaction"],"properties":{"chainId":{"type":"integer","format":"uint64","description":"Chain ID for the transaction"},"blockNumber":{"type":"integer","format":"uint64","description":"The block number on which the transaction simulation is based. If this value is 0, transaction simulation will be based on the latest block."},"transaction":{"type":"object","required":["sender","receiver","gasLimit","gasPrice","value","input"],"properties":{"sender":{"type":"string","description":"Transaction sender address"},"receiver":{"type":"string","description":"Transaction recipient address"},"gasLimit":{"type":"integer","format":"uint64","description":"Maximum gas allowed for transaction.  If this value is zero, then the simulation will be based on the gasLimit returned by eth_estimateGas."},"gasPrice":{"type":"string","pattern":"^\\d+$","description":"Gas price in wei (as integer string). If this value is zero, then the simulation will be based on the gasPrice returned by eth_gasPrice."},"value":{"type":"string","pattern":"^\\d+$","description":"Transaction value in wei (as integer string)"},"input":{"type":"string","description":"Transaction calldata in hex format"}}},"enableCodeOverwrite":{"type":"boolean","description":"Enable Safe-signature-bypass for the simulation. Defaults to false."},"overwriteAddresses":{"type":"array","items":{"type":"string"},"description":"Addresses on which Safe-signature-bypass should be applied. Only used when enableCodeOverwrite is true. Duplicates are ignored. If omitted or empty, falls back to transaction.receiver."}}},"SimulationTraceResponse":{"type":"object","required":["code","message","data"],"properties":{"code":{"type":"integer","format":"int32"},"message":{"type":"string"},"data":{"$ref":"#/components/schemas/TransactionTraceData"}}},"TransactionTraceData":{"allOf":[{"$ref":"#/components/schemas/TransactionData"},{"type":"object","properties":{"trace":{"$ref":"#/components/schemas/Call"}},"required":["trace"]}]},"TransactionData":{"type":"object","required":["status","blockNumber","txnHash","sender","receiver","timestamp","callData","gasLimit","gasPrice","gasUsed","baseFee","transactionFee","nonce","value","errorInfo","balanceChanges","viewLink"],"properties":{"status":{"type":"boolean","description":"Transaction execution status (true/false)"},"blockNumber":{"type":"integer","format":"uint64","description":"Block number"},"txnHash":{"type":"string","description":"Transaction hash"},"sender":{"type":"string","description":"Transaction initiator address"},"receiver":{"type":"string","description":"Transaction recipient address"},"timestamp":{"type":"string","format":"date-time","description":"Transaction timestamp"},"callData":{"type":"string","description":"Transaction calldata in hex format"},"gasLimit":{"type":"integer","format":"uint64","description":"Maximum gas allowed for transaction"},"gasPrice":{"type":"string","pattern":"^\\d+$","description":"Gas price in wei (as integer string)"},"gasUsed":{"type":"integer","format":"uint64","description":"Actual gas used in the transaction"},"baseFee":{"type":"string","pattern":"^\\d+$","description":"Base fee for EIP-1559 transactions in wei (as integer string)"},"transactionFee":{"type":"string","pattern":"^\\d+$","description":"Total transaction fee in wei (as integer string)"},"nonce":{"type":"integer","format":"uint64","description":"Sender's nonce (equal to number of transactions sent by sender)"},"value":{"type":"string","pattern":"^\\d+$","description":"Transaction value in wei (as integer string)"},"errorInfo":{"type":"string","description":"Error information when status is false"},"balanceChanges":{"type":"array","items":{"$ref":"#/components/schemas/BalanceChange"},"description":"List of account balance changes"},"viewLink":{"type":"string","description":"Phalcon Explorer view link for the transaction simulation"}}},"BalanceChange":{"type":"object","required":["account","assets"],"properties":{"account":{"type":"string","description":"Account address (asset holder)"},"assets":{"type":"array","items":{"$ref":"#/components/schemas/Asset"},"description":"List of asset changes"}}},"Asset":{"type":"object","required":["address","tokenId","rawAmount","amount","iconUrl","isERC1155","isERC721","sign","value"],"properties":{"address":{"type":"string","description":"Token contract address"},"tokenId":{"type":"string","description":"Token ID for ERC721/ERC1155 (empty string for ERC20)"},"rawAmount":{"type":"string","pattern":"^\\d+$","description":"Raw amount (unprocessed by decimals) as integer string"},"amount":{"type":"string","description":"Formatted amount (rawAmount / 10^decimals), empty if decimals missing"},"iconUrl":{"type":"string","description":"URL for token icon (empty if unavailable)"},"isERC1155":{"type":"boolean","description":"Indicates ERC1155 token"},"isERC721":{"type":"boolean","description":"Indicates ERC721 token"},"sign":{"type":"boolean","description":"Indicates sign of rawAmount/amount (positive/negative)"},"value":{"type":"string","description":"USD value of asset in decimal format.\nEmpty if missing token price or decimals information.\nExamples: \n- \"22.94604\" (with USD value)\n- \"\" (no pricing data)\n"}}},"Call":{"type":"object","description":"Represents a single EVM execution step, including nested calls and logs.","properties":{"id":{"type":"integer","description":"Represents the execution order of the transaction."},"status":{"type":"boolean","description":"Execution status of the call (true if successful, false otherwise)."},"error":{"type":"string","description":"Error message when the call failed (empty if successful)."},"type":{"type":"string","description":"Type of call (e.g., CALL, DELEGATECALL, STATICCALL, CREATE, CREATE2)."},"from":{"type":"string","description":"Address of the caller (sender of this call)."},"to":{"type":"string","description":"Address of the callee (recipient of this call)."},"value":{"type":"string","description":"ETH value (in wei) transferred in this call."},"input":{"type":"string","description":"Input calldata (hex-encoded) provided to this call."},"output":{"type":"string","description":"Return data (hex-encoded) produced by this call."},"gasLimit":{"type":"integer","format":"uint64","description":"Gas provided for this call."},"gasUsed":{"type":"integer","format":"uint64","description":"Actual gas consumed by this call."},"calls":{"type":"array","description":"Nested sub-calls triggered during this call.","items":{"$ref":"#/components/schemas/Call"}},"logs":{"type":"array","description":"Logs emitted during this call.","items":{"$ref":"#/components/schemas/Log"}}}},"Log":{"type":"object","description":"Represents an Ethereum log event emitted during execution.","properties":{"id":{"type":"integer","description":"Represents the execution order of the transaction."},"address":{"type":"string","description":"Address of the contract that emitted the log."},"topics":{"type":"array","items":{"type":"string"},"description":"Indexed event topics (up to 4), hex-encoded."},"data":{"type":"string","description":"Non-indexed event data payload (hex-encoded)."}}}}}}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.blocksec.com/transaction-insights/transaction-simulation-api.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.