devInspectTransactionBlock | Sui API Docs

Debug and inspect Sui transaction execution with detailed traces. Analyze Move function calls, gas usage, and execution paths with Dwellir's Sui RPC.

Executes a transaction in dev-inspect mode for debugging, providing detailed execution information without state changes.

Overview

The sui_devInspectTransactionBlock method runs transactions in a special debugging mode that provides comprehensive execution details including return values from Move functions, detailed gas profiling, and execution traces. This is invaluable for smart contract development and debugging complex transactions.

async function testMoveFunction(packageId, module, func, args) {
  const tx = new TransactionBlock();
  
  const result = tx.moveCall({
    target: `${packageId}::${module}::${func}`,
    arguments: args
  });
  
  const inspection = await client.devInspectTransactionBlock({
    sender: '0x0', // Can use any address for inspection
    transactionBlock: tx
  });
  
  if (inspection.effects.status.status !== 'success') {
    console.error('Function failed:', inspection.error);
    return null;
  }
  
  // Extract and decode return values
  const returns = inspection.results?.[0]?.returnValues || [];
  return returns.map(([data, type]) => {
    // Decode based on type
    return bcs.de(type, data);
  });
}

Gas Profiling

JavaScript

async function profileGasUsage(tx, sender) {
  const result = await client.devInspectTransactionBlock({
    sender,
    transactionBlock: tx
  });
  
  const gas = result.effects.gasUsed;
  
  console.log('Gas Profile:');
  console.log('├─ Computation:', gas.computationCost);
  console.log('├─ Storage:', gas.storageCost);
  console.log('├─ Rebate:', gas.storageRebate);
  console.log('└─ Total:', 
    Number(gas.computationCost) + 
    Number(gas.storageCost) - 
    Number(gas.storageRebate)
  );
  
  return gas;
}

Event Analysis

JavaScript

async function analyzeEvents(tx, sender) {
  const result = await client.devInspectTransactionBlock({
    sender,
    transactionBlock: tx
  });
  
  const eventsByType = {};
  
  result.events.forEach(event => {
    const type = event.type.split('::').pop();
    if (!eventsByType[type]) {
      eventsByType[type] = [];
    }
    eventsByType[type].push(event.parsedJson);
  });
  
  console.log('Events emitted:', Object.keys(eventsByType));
  return eventsByType;
}

Complex Transaction Debugging

JavaScript

async function debugComplexTransaction() {
  const tx = new TransactionBlock();
  
  // Multiple operations
  const [coin1, coin2] = tx.splitCoins(tx.gas, [
    tx.pure(1000000),
    tx.pure(2000000)
  ]);
  
  // First Move call
  const result1 = tx.moveCall({
    target: '0xdefi::swap::swap',
    arguments: [coin1, tx.pure('0x2::sui::SUI')]
  });
  
  // Second Move call using first result
  const result2 = tx.moveCall({
    target: '0xdefi::pool::add_liquidity',
    arguments: [result1, coin2]
  });
  
  // Inspect execution
  const inspection = await client.devInspectTransactionBlock({
    sender: '0xsender',
    transactionBlock: tx
  });
  
  // Analyze each call's results
  inspection.results?.forEach((result, idx) => {
    console.log(`Call ${idx} results:`, result.returnValues);
  });
  
  return inspection;
}

Best Practices

Use for development only - Not for production validation
Test with realistic sender - Some functions check sender permissions
Decode return values properly - Use correct BCS types
Check gas estimates - More accurate than dry run for complex transactions
Analyze event emissions - Verify correct events are emitted

Differences from Other Methods

Method	Purpose	Returns	State Change
`devInspectTransactionBlock`	Debugging	Return values, detailed traces	No
`dryRunTransactionBlock`	Gas estimation	Effects preview	No
`executeTransactionBlock`	Execution	Transaction receipt	Yes

sui_dryRunTransactionBlock - Simulate for gas estimation
sui_executeTransactionBlock - Execute transaction
sui_getTransactionBlock - Get executed transaction details

Need help? Contact our support team or check the Sui documentation.

sui_devInspectTransactionBlock - Debug S...

Overview

Code Examples

Debugging Use Cases

Testing Move Functions

Gas Profiling

Event Analysis

Complex Transaction Debugging

Best Practices

Differences from Other Methods

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