Implemented core execution engine components for building and executing arbitrage transactions with flashloan support.
Transaction Builder (transaction_builder.go):
- Builds executable transactions from arbitrage opportunities
- Protocol-specific transaction encoding (V2, V3, Curve)
- Single and multi-hop swap support
- EIP-1559 gas pricing with profit-based optimization
- Slippage protection with configurable basis points
- Gas limit estimation with protocol-specific costs
- Transaction validation and profit estimation
- Transaction signing with private keys
Protocol Encoders:
- UniswapV2Encoder (uniswap_v2_encoder.go):
* swapExactTokensForTokens for single and multi-hop
* swapExactETHForTokens / swapExactTokensForETH
* Proper ABI encoding with dynamic arrays
* Path building for multi-hop routes
- UniswapV3Encoder (uniswap_v3_encoder.go):
* exactInputSingle for single swaps
* exactInput for multi-hop with encoded path
* exactOutputSingle for reverse swaps
* Multicall support for batching
* Q64.96 price limit support
* 3-byte fee encoding in paths
- CurveEncoder (curve_encoder.go):
* exchange for standard swaps
* exchange_underlying for metapools
* Dynamic exchange for newer pools
* Coin index mapping helpers
* get_dy for quote estimation
Flashloan Integration (flashloan.go):
- Multi-provider support (Aave V3, Uniswap V3, Uniswap V2)
- Provider selection based on availability and fees
- Fee calculation for each provider:
* Aave V3: 0.09% (9 bps)
* Uniswap V3: 0% (fee paid in swap)
* Uniswap V2: 0.3% (30 bps)
- AaveV3FlashloanEncoder:
* flashLoan with multiple assets
* Mode 0 (no debt, repay in same tx)
* Custom params passing to callback
- UniswapV3FlashloanEncoder:
* flash function with callback data
* Amount0/Amount1 handling
- UniswapV2FlashloanEncoder:
* swap function with callback data
* Flash swap mechanism
Key Features:
- Atomic execution with flashloans
- Profit-based gas price optimization
- Multi-protocol routing
- Configurable slippage tolerance
- Deadline management for time-sensitive swaps
- Comprehensive error handling
- Structured logging throughout
Configuration:
- Default slippage: 0.5% (50 bps)
- Max slippage: 3% (300 bps)
- Gas limit multiplier: 1.2x (20% buffer)
- Max gas limit: 3M gas
- Default deadline: 5 minutes
- Max priority fee: 2 gwei
- Max fee per gas: 100 gwei
Production Ready:
- All addresses for Arbitrum mainnet
- EIP-1559 transaction support
- Latest signer for chain ID
- Proper ABI encoding with padding
- Dynamic array encoding
- Bytes padding to 32-byte boundaries
Total Code: ~1,200 lines across 5 files
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
