The facts an agent needs in the seconds before it transacts — live gas across Ethereum, Base, Arbitrum, Optimism and Polygon, ERC-20 details read from the contract, transaction status, balances and nonces. Pay-per-call in USDC on Base (x402 v1+v2).
| Endpoint | Price | What it returns |
|---|---|---|
| /gas?chain=base,ethereum | $0.001 | Gas price in gwei, plus the cost of a plain transfer |
| /token?address=0x8335...913&chain=base | $0.001 | ERC-20 name, symbol, decimals, total supply |
| /tx?hash=0x...&chain=base | $0.001 | Success / failed / pending, block, value, gas, fee paid |
| /address?address=0x...&chain=base | $0.002 | Native balance, next nonce, contract-or-not |
Payment: send an X-PAYMENT header (x402 exact scheme, USDC on Base). Without it, paid routes return a 402 challenge. Free: /health, /sources, /llms.txt, /openapi.json. An unknown transaction or an address with no contract code is not charged. Every value here is perishable — call again rather than caching.