blockchain balance API for AI agent

$0.002 USDC per call on Base · No signup · No API key · x402 v2

What it does

Check balances, transactions, and gas on Base + Ethereum. Look up ETH/USDC balances, transaction details with status, and live gas prices on Base and Ethereum. No RPC node or API key needed.

Data source: Base + Ethereum public RPC

How to call (for AI agents)

No account. No API key. Every endpoint speaks x402 v2:

  1. Call the endpoint → you get 402 Payment Required with the price
  2. Pay $0.002 USDC on Base (eip155:8453)
  3. Retry with the X-PAYMENT header → 200 with JSON
curl "https://api.mekongtradeintel.com/chainread/api/chain/balance?address=0x198f3895551B309fF5C5F59e690FB0823d10EA93&chain=base"

Input

ParamTypeDescription
addressquery param0x wallet address (balance endpoint)
hashquery param0x transaction hash (tx endpoint)
chainquery parambase or ethereum (default base)

Example request & response

Request

GET /chainread/api/chain/balance?address=0x198f3895551B309fF5C5F59e690FB0823d10EA93&chain=base

Response

{
  "address": "0x198f...EA93",
  "chain": "base",
  "native": "0.0012",
  "usdc": "0.1682"
}

Payment

x402 v2 · exact scheme · USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base (eip155:8453).
Facilitators: Coinbase CDP and PayAI (no API key needed for either).

FAQ

Which chains are supported?
Base (eip155:8453) and Ethereum mainnet. Pass ?chain=base or ?chain=ethereum.

What does the tx endpoint return?
Status (success/failed/pending), from/to addresses, value in ETH, block number, and gas used.

How fresh is the data?
Latest block, typically <15 seconds behind chain head.

Do I need an API key?
No. This API uses x402: call the endpoint, receive a 402 Payment Required with the price, pay in USDC on Base, and retry with proof of payment. No signup, no API key, no account.

Which facilitators are supported?
Both Coinbase CDP and PayAI facilitators are supported for x402 v2 exact payments on Base (eip155:8453).

What if my payment is too low?
The facilitator verifies the on-chain amount against the price. If underpaid, you get 402 again; pay the full amount and retry.

More APIs for AI agents

Part of the x402 API Collection — 16 pay-per-call endpoints, $0.0008–$0.008/call. Full catalog: https://api.mekongtradeintel.com/.well-known/x402