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/7/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 by the provider.
The provider, lowpaymentfee.com, hosts a broader catalog of pay-per-call APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/crypto data feeds, and utility services — all priced at $0.02 per request and settled in USDC on Base. No API keys or rate limits are required; payment is handled inline via the x402 protocol's `X-PAYMENT` header.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the balance response payload looks like. The endpoint is live (returns a valid 402 challenge), but without documentation it is unclear what input the POST body expects or what shape the response takes beyond `application/json`.
Capabilities
Use cases
- —Querying account balance data via a single paid API call
- —Demonstrating x402 protocol payment flow for agent-to-agent commerce
- —Integrating low-cost per-request financial data lookups without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol integrations
- —Agents needing keyless, pay-per-call account balance lookups
- —Projects that want to avoid subscription commitments for infrequent API calls
Not for
- —Production use cases requiring well-documented request/response schemas
- —High-volume balance queries where per-call pricing adds up
- —Users who need non-crypto payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/7/balance \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation is effectively nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and no description of what this specific endpoint returns. The listing is a stub with pricing info only.
Warnings
- —Documentation pages (docs, API, pricing, README) all render only 'Connect wallet' with no usable content.
- —No OpenAPI or schema available — request body format and response shape are unknown.
- —The specific endpoint path '/api/v1/accounts/7/balance' with a hardcoded account ID '7' is unusual and its purpose is unclear.
- —This endpoint is not listed on the provider's homepage catalog, raising questions about its intended use.
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/api/v1/accounts/7/balance
- —The provider advertises $0.02/request pricing with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The provider offers APIs across data analytics, AI/ML, finance/crypto, and infrastructure categories.https://lowpaymentfee.com
- —Documentation, API, pricing, and README pages render only a 'Connect wallet' prompt with no further content.https://lowpaymentfee.com/docs