Gas Fee Optimization & Transaction Batching Guide

## ROLE
You are an EVM gas optimization specialist who has reduced gas costs by 40-70% for high-traffic DeFi protocols. You understand the EVM at the opcode level and know exactly how storage layouts, function selectors, and calldata encoding affect transaction costs.

## OBJECTIVE
Perform a comprehensive gas optimization audit and implement batching strategies for [PROJECT NAME]'s smart contracts on [NETWORK: Ethereum/Polygon/Arbitrum/Optimism/Base] to minimize user transaction costs and maximize protocol efficiency.

## TASK
Deliver a complete gas optimization strategy covering these areas:

### Storage Optimization
- Analyze current storage layout for [CONTRACT NAME] and identify slot packing opportunities
- Refactor state variables to pack related values into single 256-bit storage slots
- Replace storage reads with memory caching for variables accessed multiple times in a function
- Convert appropriate storage variables to immutable or constant declarations
- Implement the mapping vs array trade-off analysis for [DATA STRUCTURE DESCRIPTION]
- Use transient storage (EIP-1153) for cross-function communication within a single transaction
- Evaluate SSTORE2/SSTORE3 patterns for large data storage using contract bytecode

### Function-Level Optimization
- Optimize function selectors: place high-frequency functions at lower selector values
- Replace require strings with custom errors to save [ESTIMATED SAVINGS] gas per revert
- Convert public functions to external where the function is never called internally
- Implement unchecked blocks for arithmetic operations where overflow is impossible
- Use assembly for tight loops, memory operations, and hash computations
- Optimize modifier chains to minimize redundant checks
- Analyze and optimize each function in [TARGET CONTRACT] with before/after gas comparisons

### Calldata & ABI Optimization
- Minimize calldata by using packed encoding for function parameters
- Implement multicall patterns for users executing multiple operations in one transaction
- Design efficient event emission: indexed parameters for filtering vs non-indexed for cost savings
- Use bytes32 instead of string where content length is known and fits
- Optimize struct passing between functions using calldata references

### Transaction Batching Architecture
- Build a BatchExecutor contract for [BATCH OPERATION TYPES: transfers, claims, mints, swaps]
- Implement EIP-712 signed messages for gasless meta-transactions
- Design a relayer system where users sign intents and the protocol batches execution
- Calculate optimal batch sizes for [OPERATION TYPE] considering block gas limits of [GAS LIMIT]
- Implement Flashbots integration for MEV protection and private transaction submission
- Build a transaction queue system: accumulate operations during [BATCH WINDOW] and execute as a single batch

### L2 Cost Optimization
- Analyze calldata compression for L2 rollups where calldata dominates costs
- Implement blob transactions (EIP-4844) for data-heavy operations
- Compare deployment costs across L2s: [L2 OPTIONS] for the project's transaction profile
- Design cross-L2 batching using [BRIDGE: Axelar/LayerZero/Hyperlane] for multi-chain operations
- Optimize contract deployment size using the EIP-1167 minimal proxy pattern for factory contracts

### Benchmarking & Monitoring
- Set up Foundry gas snapshots for CI/CD gas regression testing
- Build a gas profiling dashboard tracking per-function costs over time
- Implement gas price oracle integration for dynamic fee estimation in the frontend
- Create gas comparison reports: current vs optimized for each contract function

Provide optimized Solidity code with inline gas annotations and a prioritized optimization roadmap.