optimizing-gas-fees

# Optimizing Gas Fees

## Overview

Gas fee optimization skill that:
- Fetches real-time gas prices from multiple sources
- Estimates transaction costs in ETH and USD
- Analyzes historical patterns to find optimal timing
- Predicts future gas prices
- Compares gas across multiple chains

## Prerequisites

- Python 3.8+ with requests library
- Network access to RPC endpoints
- Optional: `ETHERSCAN_API_KEY` for higher rate limits
- Optional: Custom RPC URLs via environment variables

## Instructions

1. Check current gas prices (optionally for a specific chain):
   ```bash
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py current
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py current --chain polygon
   ```
2. Estimate transaction cost for known operations or custom gas limits (available operations: `eth_transfer`, `erc20_transfer`, `erc20_approve`, `uniswap_v2_swap`, `uniswap_v3_swap`, `sushiswap_swap`, `curve_swap`, `nft_mint`, `nft_transfer`, `opensea_listing`, `aave_deposit`, `aave_withdraw`, `compound_supply`, `compound_borrow`, `bridge_deposit`):
   ```bash
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py estimate --operation uniswap_v2_swap --all-tiers
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py estimate --gas-limit 150000 --tier fast  # 150000 = configured value
   ```
3. Find the optimal transaction window with lowest expected gas:
   ```bash
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py optimal
   ```
4. View gas patterns (hourly or daily):
   ```bash
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py patterns
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py patterns --daily
   ```
5. Predict future gas prices for a given hour:
   ```bash
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py predict --time 14
   ```
6. Compare gas prices across multiple chains:
   ```bash
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py compare
   ```
7. View base fee history for recent blocks:
   ```bash
   cd ${CLAUDE_SKILL_DIR}/scripts && python3 gas_optimizer.py history --blocks 50
   ```

## Output

- **Current**: Base fee, priority fee, and tier prices (slow/standard/fast/instant)
- **Estimate**: Gas cost in native token and USD for each tier
- **Patterns**: Historical hourly/daily patterns with low-gas markers
- **Optimal**: Recommended transaction window with expected savings
- **Predict**: Gas forecast for specific time with confidence
- **Compare**: Side-by-side gas prices across chains

## Supported Chains

| Chain | Native Token | Block Time |
|-------|--------------|------------|
| Ethereum | ETH | ~12 sec |
| Polygon | MATIC | ~2 sec |
| Arbitrum | ETH | ~0.25 sec |
| Optimism | ETH | ~2 sec |
| Base | ETH | ~2 sec |

## Price Tiers

| Tier | Percentile | Confirmation Time |
|------|------------|-------------------|
| Slow | 10th | 10+ blocks (~2+ min) |
| Standard | 50th | 3-5 blocks (~1 min) |
| Fast | 75th | 1-2 blocks (~30 sec) |
| Instant | 90th | Next block (~12 sec) |

## Error Handling

See `${CLAUDE_SKILL_DIR}/references/errors.md` for:
- RPC connection issues
- API rate limiting
- Price feed errors
- Pattern analysis errors

## Examples

See `${CLAUDE_SKILL_DIR}/references/examples.md` for:
- Quick start commands
- Cost estimation scenarios
- Multi-chain comparison
- Practical workflows

## Resources

- [EIP-1559](https://eips.ethereum.org/EIPS/eip-1559) - Fee market specification
- [Etherscan Gas Tracker](https://etherscan.io/gastracker) - Reference oracle
- [L2Fees](https://l2fees.info/) - L2 cost comparison