# x402 Chain Tools

Blockchain wallet, token, transaction and preflight tools for AI agents.

Data network: Base Mainnet (eip155:8453). All seven tools continue to return Base blockchain data; the payment network does not change tool semantics. The service does not sign, submit, or simulate transactions.

## Payment

The seven chain tools use x402 V2 exact-scheme USDC payment per request. Accepted payment networks: Base Mainnet USDC (eip155:8453) or Solana Mainnet USDC (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp). An unpaid POST returns the authoritative PAYMENT-REQUIRED challenge.

## Paid tools

- POST /chain/block: Check the latest or current Base Mainnet block number. Use this to get the live Base block height. Payment required ($0.001 USDC via x402).
- POST /chain/balance: Check the native ETH balance or gas balance of a Base wallet address. Use this to see how much Base ETH the wallet has. Payment required ($0.001 USDC via x402).
- POST /chain/token-balance: Get ERC20 token balance for a Base wallet address. Use an ERC20 token contract address to return raw, decimal, and formatted token balance values. Payment required ($0.001 USDC via x402).
- POST /chain/allowance: Get ERC20 allowance for an owner wallet and spender on Base. Return the approved token amount and whether the allowance is unlimited. Payment required ($0.001 USDC via x402).
- POST /chain/transaction-lookup: Lookup Base transaction by hash on Base Mainnet. Return sender, recipient, value, nonce, block, gas fields, and input data when found. Payment required ($0.002 USDC via x402).
- POST /chain/transaction-receipt-status: Check Base transaction receipt status by transaction hash. Determine whether the transaction is pending, confirmed successful, or confirmed reverted, with receipt, block, and gas details. Payment required ($0.002 USDC via x402).
- POST /chain/wallet-preflight: Wallet preflight: check wallet readiness before token spend on Base. Verify native ETH gas balance, ERC20 token balance, allowance, spender contract status, and whether the requested amount can be spent. Payment required ($0.002 USDC via x402).

## Free machine-readable resources

- GET /health
- GET /openapi.json — OpenAPI 3.1 contract
- GET /capabilities — compact capability catalogue
- GET /.well-known/x402 — canonical service manifest alias
- GET /.well-known/x402-service.json — project-owned x402 service manifest
- GET /llms.txt
- GET /robots.txt