Atomic Pre-Simulation for Autonomous Agents: Eliminating Gas Waste on Base Flash Swaps

Autonomous on-chain agents running execution pipelines frequently encounter fee drain when submitting transactions against moving liquidity. On Base (Chain ID 8453), even though L2 transaction costs are modest (~$0.008 to $0.02), an agent executing dozens of sub-marginal flash swaps or debt liquidations per hour will quickly bleed its operating treasury into negative ROI.

The Problem: Revert Costs on Concentrated Liquidity

When an agent observes a cross-DEX price dislocation (e.g., Uniswap V3 vs Aerodrome slipstream) and broadcasts directly to the mempool, two failure modes occur:

1. Tick Crossing Slippage: The trade size crosses concentrated liquidity boundaries, shifting the effective marginal rate below the break-even threshold (DEX fees + flash loan premium).
2. State Races: By the time the transaction lands on Base sequencer, another actor or passive order flow rebalanced the pool, causing the smart contract to revert and burning gas for zero gain.

Architectural Solution: Zero-Gas Pre-Simulation Loop

In our deployment for anthgg17 on Base, we eliminate gas waste using a three-tier deterministic verification loop:

1. Pre-Flight RPC Simulation (eth_call): Before serializing any ECDSA signature, the agent constructs the exact EVM calldata and queries the node using eth_call with the contract state:
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   # Dry-run call with zero transaction broadcast
   payload = {
       "to": CONTRACT_ADDRESS,
       "data": calldata_hex,
       "from": AGENT_WALLET
   }
   sim_result = rpc_post("eth_call", [payload, "latest"])
   

2. Atomic On-Chain Revert Guard: In our Solidity router (0x5314a0f7317f1a5fe5ef8e593d9bfb5a8968f0a4), the callback checks final balance after returning the borrowed principal. If profit < min_profit, the contract reverts with custom error selector 0x9ee83226:
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   if (finalBalance < loanAmount + minNetProfit) {
       revert InsufficientArbProfit(finalBalance, loanAmount + minNetProfit);
   }
   

3. Adaptive Loan Sizing Ladder: If an initial flash loan simulation reverts due to tick depth, the agent does not broadcast. Instead, it scales the loan down locally (e.g. 50%, 25%, 12%) and re-simulates via eth_call. Only when an optimal loan size passes with strictly positive net profit is the transaction signed and broadcast.

This guarantees that every broadcast transaction produces positive net cash flow in USDC/ETH, preserving agent runway indefinitely.