x402-gated account balance endpoint on Base, pay-per-call with 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/131/balance` is gated behind a per-request USDC payment on the Base network. The x402 challenge indicates a maximum cost of 20,000 base units of USDC (0.02 USD) per request, consistent with the site-wide $0.02/request pricing advertised across all endpoints.
lowpaymentfee.com hosts a broader suite of x402-gated APIs spanning data & analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints share the same $0.02 per-request pricing with no API keys, no rate limits, and no minimum commitments. Payments settle in USDC on the Base L2 network.
The specific endpoint probed here (`/api/v1/accounts/131/balance`) is listed under the title "Premium API Access" but its actual functionality — returning an account balance — is not well-documented. The crawled docs, pricing, API, and README pages all rendered only a "Connect wallet" prompt with no additional technical documentation, schemas, or example responses. The endpoint is confirmed live (returns a valid x402 402 challenge), but the lack of documentation makes it difficult to know what request body to send or what response shape to expect.
Capabilities
Use cases
- —Querying account balance information via a single paid API call
- —Integrating pay-per-request balance lookups into agent workflows
- —Demonstrating x402 protocol payment flows on Base
Fit
Best for
- —Agents or developers needing on-demand account balance data without API key management
- —x402 protocol experimentation and integration testing
- —Low-volume, pay-as-you-go API consumption
Not for
- —High-volume balance polling where per-request fees add up quickly
- —Users who need detailed API documentation and response schemas before integrating
- —Use cases requiring non-USDC or non-Base payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/131/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no documentation, no request/response schema, no examples, and the docs/pricing/API pages all render only a wallet-connect prompt. The actual purpose of this specific endpoint (account 131 balance) is opaque.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No request body schema or response schema provided
- —The endpoint path references a specific account ID (131); unclear if this is parameterizable or a fixed demo
- —The description 'Premium API Access' is generic and does not explain what data is returned
Citations
- —The x402 challenge requires a maximum of 20,000 base units of USDC (USD Coin) on the Base network, equating to $0.02 per request.https://lowpaymentfee.com
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The site hosts endpoints across data & analytics, AI/ML, finance & Web3, and infrastructure categories.https://lowpaymentfee.com