Gas Fees Killed Our First Demo. Here's What We Did About It.

The investor meeting was going perfectly. We had built an AI agent that could autonomously pay for API calls, route micro-transactions across services, and settle in real time. Then we ran the live demo. The transaction confirmed in 14 seconds. The room was impressed. Then our lead investor leaned forward and said: "What did that just cost?" The answer was $8.40 in gas fees. For a $0.15 API call. The demo was dead. The Gas Fee Math Nobody Talks About Ethereum mainnet gas fees are priced in gwei per unit of gas. A simple ETH transfer uses 21,000 gas units. An ERC-20 token transfer uses 45,000-65,000 gas units. During the demo, mainnet was running at 80 gwei base fee with a 10 gwei priority fee. # Gas cost formula gas_units = 65000 base_fee_gwei = 80 priority_fee_gwei = 10 eth_price_usd = 3200 total_gwei = gas_units * ( base_fee_gwei + priority_fee_gwei ) total_eth = total_gwei / 1e9 gas_cost_usd = total_eth * eth_price_usd print ( f " Gas cost: $ { gas_cost_usd : . 2 f } " ) # Gas cost: