x402-gated account balance endpoint on Base, paying $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides an account balance lookup via the x402 payment protocol. The specific resource `/api/v1/accounts/33/balance` is one entry point on 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 settled in USDC on the Base network.
The endpoint is live and returns a standard x402 challenge (HTTP 402) requiring an `X-PAYMENT` header with an exact-scheme payment of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals → $0.02). Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The response MIME type is `application/json` and the method is POST.
Documentation beyond the landing page is extremely thin — the /docs, /api, /pricing, and /README 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 "balance" resource actually returns or what input it expects. The platform markets itself as having no API keys, no rate limits, and instant access, but the actual behavior of this specific endpoint is undocumented.
Capabilities
Use cases
- —Querying account balance data via a pay-per-request model without API key registration
- —Integrating x402-compatible agents with low-cost financial data endpoints
- —Demonstrating x402 protocol payment flows on Base
Fit
Best for
- —Agents that support x402 payment protocol on Base
- —Developers exploring pay-per-call API patterns without signup
- —Low-volume balance lookups where $0.02/request is acceptable
Not for
- —High-volume balance queries where per-request costs add up
- —Users needing detailed API documentation or guaranteed SLAs
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/33/balance \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what the endpoint actually does, what inputs it accepts, or what the response looks like. No OpenAPI spec, no examples, and all doc pages just show 'Connect wallet'. The listing title 'Premium API Access' is generic and uninformative. Effectively a stub.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README all render only 'Connect wallet'
- —No OpenAPI or request/response schema provided; impossible to know what this endpoint returns
- —The endpoint path references a hardcoded account ID (33); unclear if this is parameterizable
- —Platform advertises many API categories but none have documented behavior
Citations
- —Endpoint returns HTTP 402 with x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/accounts/33/balance
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/accounts/33/balance
- —All APIs priced at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Platform lists categories: Data & Analytics, AI & Machine Learning, Finance & Web3, Infrastructurehttps://lowpaymentfee.com