Pre-Swap Simulator — Simulate Before You Swap
Simulate a token swap on Base — amount out, price impact, fee and gas — before you sign the transaction.
Never be surprised by a swap again. Paste token addresses and an amount and the simulator returns the expected amount out, exchange rate, price impact, fee and gas estimate — with a GO / caution recommendation. Perfect for checking trades on Base before you sign. Free 5 simulations per day per IP, no signup.
Daily free limit reached
You've used your 5 free uses today. Continue pay-per-use via the DeFi Intel Agent Gateway API, or add a prepaid API key above for unlimited use.
Use this at scale or in your own tools
The same engine powers the DeFi Intel Agent Gateway: 40+ paid microservices on USDC (Base), no API keys required for pay-per-call, MCP transport for AI agents. Free samples daily.
Frequently asked questions
Is the pre-swap simulator free?
Yes — 5 free simulations per day per IP, no signup. Beyond that, use the DeFi Intel Agent Gateway API (pay-per-use) or a prepaid API key.
What do I get back?
The expected amount out (in raw and USD), exchange rate, price impact percentage, fee, gas estimate in USD, and a recommendation (GO or caution) with any warnings.
What is "amount in atomic units"?
The amount in the smallest denomination of the input token — e.g. 1 USDC = 1,000,000 (6 decimals), 1 WETH = 1,000,000,000,000,000,000 (18 decimals).
Is this a live quote?
It is a simulation based on current on-chain liquidity and pricing. Actual execution may differ slightly due to block timing and slippage — always set a sane slippage bound.
Powered by the DeFi Intel Agent Gateway (x402/MPP, USDC on Base). Free tier: 5 calls/day/IP. Prices from $0.001/call. For education — not financial advice.