transaction-simulator

name	transaction-simulator
description	Simulate transactions before execution to preview outcomes and detect failures. Save gas and prevent errors.

Transaction Simulator

When to use this skill

Use this skill BEFORE executing:

• Complex swaps or trades
• Smart contract interactions
• Large transfers
• DeFi operations (stake, lend, etc.)

What It Does

Simulates your transaction on a test environment to show:

• ✅ Will it succeed or fail?
• 📊 Expected output amounts
• 💰 Actual gas costs
• ⚠️ Warnings and errors
• 🔄 State changes preview

NO REAL TRANSACTION IS SENT - It's a safe preview!

Benefits

💰 Save Money

• Avoid failed transactions (still cost gas!)
• Preview slippage before swapping
• Verify gas estimates

🛡️ Prevent Errors

• Catch insufficient balance
• Detect approval issues
• Identify smart contract bugs

📊 Better Planning

• See exact output amounts
• Preview price impact
• Understand state changes

Usage

from skills.transaction_simulator.scripts.simulate_tx import simulate_transaction

# Simulate a swap
tx_data = {
    'from': 'TXXXabc...',
    'to': 'SunSwap_Router',
    'value': 100,
    'data': '...'  # Transaction data
}

result = await simulate_transaction(tx_data)

if result['success']:
    print(f"Expected output: {result['output_amount']}")
    print(f"Gas cost: {result['gas_used']}")
else:
    print(f"Would fail: {result['error']}")

Output Example

✅ Successful Simulation

🎮 Transaction Simulation
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Operation: Swap 100 TRX → USDT
Simulation: ✅ SUCCESS

Expected Results:
  • Output: 14.85 USDT
  • Price: 1 TRX = 0.1485 USDT
  • Slippage: 0.5%
  • Price Impact: 0.02%

Costs:
  • Gas Used: ~50,000 Energy
  • Est. Fee: 0.15 TRX

⏱️ Simulation Time: 1.2s

✅ Transaction will succeed
💡 Proceed with confidence!

❌ Failed Simulation

🎮 Transaction Simulation
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Operation: Swap 1000 TRX → SCAM_TOKEN

Simulation: ❌ FAILED

Error: "Transfer failed - Honeypot detected"

Details:
  • Cannot sell this token after buying
  • Contract has blacklist function
  • Sell tax: 99%

🚨 DO NOT EXECUTE THIS TRANSACTION!

Saved you: ~1000 TRX + gas fees

Technical Details

Simulation Methods

1. TronGrid Simulation API (if available)

   • Most accurate
   • Uses actual blockchain state

2. Local Fork Simulation

   • Creates temporary blockchain fork
   • Executes transaction locally

3. Bytecode Analysis

   • Analyzes contract code
   • Predicts execution flow

Limitations

• ⚠️ Simulations use current blockchain state
• 🕐 Actual execution may differ if state changes
• 🔄 Time-sensitive operations may behave differently
• 📊 Gas estimates are approximate

Integration

Should auto-run before:

• Any swap >$100 USD value
• User's first interaction with a contract
• Transactions to unverified contracts
• User explicitly requests simulation

Safety

✅ 100% Safe - No real transactions sent ✅ No costs - Simulation is free ✅ Privacy - Simulations run locally when possible