Query Transaction Decodes transaction data including traces, logs, and balance changes.
Returns
Decoded calldata and function calls
Parsed event logs with parameters
Token/ETH balance changes
Internal transaction traces
All contracts and addresses involved
Example Queries What happened in transaction 0x1234...?
Decode this swap transaction: 0xabcd...
Explain all the token transfers in tx 0x5678...
Parameters Parameter Required Description txHashYes The transaction hash (0x…) returnAllDataNo Return all data without filtering (default: false) balanceQueryNo Filter balance changes by query (e.g., “USDC transfers”) traceLogQueryNo Filter traces/logs by query (e.g., “swap function calls”) includeRawDataNo Include raw hex calldata (default: false) blockchainNo ethereum or base (auto-detected if not provided)
Understanding Transaction Components Balance Changes Shows all token/ETH movements:
Balance Changes: ┌──────────────┬─────────────┬────────────────┬─────────────────┐ │ Token │ From │ To │ Amount │ ├──────────────┼─────────────┼────────────────┼─────────────────┤ │ USDC │ 0xUser... │ 0xPool... │ 1,000.00 │ │ WETH │ 0xPool... │ 0xUser... │ 0.35 │ └──────────────┴─────────────┴────────────────┴─────────────────┘
Balance amounts are already decimal-adjusted (human-readable). No need to divide by decimals.
Traces Internal calls within the transaction:
Traces: 1. 0xUser calls 0xRouter.swap(...) └─ 2. 0xRouter calls 0xPool.swap(...) └─ 3. 0xPool calls 0xUSDC.transferFrom(...) └─ 4. 0xPool calls 0xWETH.transfer(...)
Event Logs Decoded events emitted:
Events: 1. Swap (0xPool) - sender: 0xRouter - amount0In: 1000000000 (1000 USDC) - amount1Out: 350000000000000000 (0.35 WETH) 2. Transfer (0xUSDC) - from: 0xUser - to: 0xPool - value: 1000000000 3. Transfer (0xWETH) - from: 0xPool - to: 0xUser - value: 350000000000000000
Basic Decode What happened in 0x8a3c4b5d6e7f...
Returns: summary, function called, token transfers, gas cost, status
Filtered Results Show me only the USDC transfers in this transaction
Uses balanceQuery to filter balance changes.
DeFi Transactions Explain this Uniswap swap step by step
Shows: function called, input/output tokens, routing path, exchange rate, fees
Real-World Examples Example 1: Simple Token Transfer Transaction: 0x123... Type: ERC-20 Transfer From: 0xAlice To: 0xBob Token: USDC Amount: 500.00 USDC Gas: 65,000 ($2.34) Status: Success
Example 2: Complex DeFi Transaction Transaction: 0x456... Type: Multi-hop Swap Protocol: Uniswap V3 Action: Swapped 10,000 USDC → 3.5 ETH Route: USDC → WETH (0.3% fee pool) Balance Changes: - User: -10,000 USDC - User: +3.5 WETH Events Emitted: 1. Approval (USDC) 2. Swap (Uniswap Pool) 3. Transfer (USDC) 4. Transfer (WETH) Effective Rate: 1 ETH = 2,857.14 USDC Gas Used: 184,532 ($8.45)
Example 3: Failed Transaction Transaction: 0x789... Status: FAILED (Reverted) Reason: "Insufficient liquidity" What Happened: User tried to swap 1M USDC for ETH Pool didn't have enough liquidity Transaction reverted after consuming 45,000 gas Gas Wasted: $1.89
Filtering Options Balance Query Examples "USDC transfers" → Only USDC movements "mints and burns" → Token minting/burning "ETH transfers" → Native ETH movements "NFT transfers" → ERC-721 movements
Trace/Log Query Examples "swap function calls" → Swap-related traces "Transfer events" → ERC-20 Transfer logs "approval events" → Token approvals "admin functions" → Privileged operations
Full Data Mode Set returnAllData: true for complete output:
All balance changes (unfiltered)
Complete trace tree
All decoded logs
Raw data (if includeRawData: true)
Tips Start broad, then filter. Ask “what happened” first, then drill into specifics.
Ask “why” questions: “Why did this fail?” or “Why so many internal calls?”
Common Questions
What if the transaction failed?
Claude will explain why it failed, show what it tried to do, and how much gas was wasted.
Can I see pending transactions?
No, only confirmed (mined) transactions can be analyzed.
What about internal transactions?
Yes! The traces show all internal calls, even those not visible on basic block explorers.
Next Steps 
