x402-gated account balance endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides a "Premium API Access" account balance lookup via the x402 payment protocol. The specific resource `/api/v1/accounts/5/balance` returns JSON data when called with a valid x402 payment header. It is part of a broader platform that advertises multiple API categories including data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per request and settled in USDC on the Base network.
The x402 challenge confirms the endpoint is live and accepts exact-scheme payments in USDC (contract 0x8335…2913 on Base) with a maximum amount of 20,000 base units, which equals $0.02 (USDC uses 6 decimals). No API keys or rate limits are advertised; access is granted purely through per-request micropayments. The payment recipient address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3, and the payment timeout is 300 seconds.
Documentation is extremely sparse — the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema, and no explanation of what the "account balance" data actually contains or what parameters it accepts. The endpoint's purpose and output format must be inferred entirely from its URL path and the x402 challenge metadata.
Capabilities
Use cases
- —Querying account balance data via a single micropayment
- —Demonstrating x402 protocol integration for pay-per-call APIs
- —Agent-driven balance lookups without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-per-call API access on Base
- —Low-volume balance queries where per-request pricing is preferred
Not for
- —Production use cases requiring documented request/response schemas
- —High-volume balance lookups where subscription pricing would be cheaper
- —Users who need detailed API documentation before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/5/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI spec, no request/response schema, and no explanation of what the endpoint actually returns. The docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and API pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema describing request parameters or response format
- —The specific purpose of '/api/v1/accounts/5/balance' (what account, what balance) is unexplained
- —No examples of successful responses are available
- —The broader platform lists many endpoints but none appear documented
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/accounts/5/balance
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/accounts/5/balance