Slippage Protector

WHAT IT DOES

Slippage Protector gives DeFi traders and liquidity providers real-time insight into swap slippage and price impact before executing trades. It reads live on-chain data including pool reserves, token prices, router contract state, expected vs actual output amounts, transaction simulation data, and gas price oracles. You can simulate token swaps, calculate expected output, determine minimum output with your chosen slippage tolerance, measure price impact, estimate gas costs, and assess overall trade risk. The tool shows you in real time whether your slippage tolerance is sufficient to cover price impact, what your minimum output will be, and how much you'll pay in gas—so you can avoid costly trade execution mistakes.

HOW TO USE

Connect your EVM wallet (optional—the tool can work in read-only mode). Enter the router contract address (e.g., Uniswap V2 router), token in address, and token out address. Set the amount you want to swap and your slippage tolerance percentage (e.g., 0.5%). Click "Simulate swap" to fetch current data from the chain. The tool displays the router address, token details, amount in, expected output, minimum output with slippage, price impact percentage, slippage risk level (Low/Medium/High), and gas estimate in ETH. A visual dashboard shows price impact vs. your slippage tolerance with progress bars, and a risk assessment badge indicates whether your trade is safe.

TECHNICAL APPROACH

This tool queries live contract state using ethers v5.7.2. It calls getAmountsOut() on the router contract to simulate the swap and get the expected output amount. It reads token decimals to format amounts correctly. The tool calculates minimum output by applying the user's slippage tolerance to the expected output. It estimates gas costs by calling estimateGas.swapExactTokensForTokens() on the router and multiplying by the current gas price. Price impact is calculated by comparing the trade amount to pool reserves. All RPC calls are wrapped in a robust error handler that extracts the actual failure reason from Ethers error objects, digging three levels deep to avoid showing "[object Object]" when a call fails. The tool uses fallback gas estimates if the simulation estimate fails.

WHAT IT CANNOT SEE

This tool cannot predict mempool conditions, front-running, or sandwich attacks. It cannot guarantee that simulated slippage matches actual execution. It cannot account for changes in pool reserves between simulation and transaction execution. It cannot detect pending transactions that might affect the pool state. It cannot simulate complex multi-hop routes beyond the path provided. It cannot account for fee tiers or other router-specific mechanics. It cannot guarantee that the gas estimate will match actual gas usage. The tool provides a simulation based on current state, but it does not guarantee that the trade will execute with the simulated values.

PLEASE NOTE

This tool supports EVM‑compatible chains only (Ethereum, Goerli, Sepolia, Arbitrum, Optimism, Polygon). Solana, Tron, Starknet, SUI, TON, Aptos, Bitcoin, Cosmos, and XRP are not supported. The tool is read‑only and does not require signing transactions—connect is optional. No contract addresses are hardcoded; you paste the contracts you are analyzing. The tool is free and open under the BotGentz PLAYBOOK‑C specification.