x402-gated account balance endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides a pay-per-request "Premium API Access" resource at the path `/api/v1/accounts/124/balance`. It is part of a broader platform that offers dozens of x402-gated API endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services — all priced at $0.02 per request and settled in USDC on the Base network.
The specific endpoint probed (`/api/v1/accounts/124/balance`) returns a live 402 challenge with an x402 v1 payment scheme. The challenge specifies the "exact" payment scheme on the Base network, accepting USDC (contract `0x8335…2913`) with a maximum amount of 20,000 base units — which, at 6 decimals for USDC, equals $0.02 per call. Payment is made via the `X-PAYMENT` header; no API keys or accounts are required. The timeout for payment settlement is 300 seconds.
The platform advertises no rate limits, no API keys, no minimums, and instant access. However, documentation beyond the landing page is extremely thin — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed documentation for what the `/api/v1/accounts/124/balance` endpoint actually returns. The endpoint's purpose (account balance lookup) is inferred solely from its URL path and the generic "Premium API Access" description.
Capabilities
Use cases
- —Querying account balance data via a single paid API call
- —Integrating pay-per-request balance lookups into agent workflows
- —Demonstrating x402 payment protocol usage on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing on-demand account balance data without API key management
- —Low-volume, pay-as-you-go API consumption
Not for
- —High-volume production workloads requiring documented SLAs and schemas
- —Users who need detailed API documentation or response format guarantees
- —Anyone needing free or subscription-based access
Quick start
# 1. Send a POST to the endpoint without payment to get the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/accounts/124/balance
# 2. Parse the 402 response, construct an x402 USDC payment on Base,
# then resend with the X-PAYMENT header:
curl -X POST https://lowpaymentfee.com/api/v1/accounts/124/balance \
-H "X-PAYMENT: <signed-x402-payment>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI schema, no request/response examples, and no meaningful documentation — docs pages only show 'Connect wallet'. The purpose of this specific endpoint is unclear beyond its URL path. Pricing is clear ($0.02/call in USDC on Base).
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no content
- —The exact purpose and response format of /api/v1/accounts/124/balance is unknown — inferred only from URL path
- —No request body schema or response examples are provided anywhere
Citations
- —The endpoint returns a live 402 challenge with x402 v1, exact scheme, on Base network, accepting USDC at max 20000 base units (=$0.02)https://lowpaymentfee.com/api/v1/accounts/124/balance
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, no minimums, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/accounts/124/balance
- —Documentation pages render only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs