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/130/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 provider's site-wide $0.02/request pricing model.
The provider, 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 are advertised at $0.02 per request with no API keys, no rate limits, and instant access. Payment settles in USDC on the Base L2 network.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the balance endpoint actually returns. The endpoint is confirmed live (returns a valid x402 402 challenge), but the lack of documentation makes it difficult to know what payload to send or what response to expect.
Capabilities
Use cases
- —Querying account balance information via a pay-per-request model
- —Integrating x402 micropayment-gated API calls into agent workflows
- —Accessing financial data without traditional API key provisioning
Fit
Best for
- —Agents or applications that already support x402 payment flows
- —Users who want keyless, pay-as-you-go API access
- —Developers experimenting with x402 protocol integration on Base
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —High-volume use cases where per-request pricing may not be cost-effective
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/130/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty beyond a wallet-connect prompt. The purpose of the specific /accounts/130/balance resource is only inferable from its URL path.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema describing request parameters or response format
- —The specific endpoint path (/api/v1/accounts/130/balance) has a hardcoded account ID (130); unclear if this is parameterizable
- —Purpose and response structure of the balance endpoint are unknown — only the URL path suggests it returns an account balance
Citations
- —The x402 challenge returns maxAmountRequired of 20,000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/accounts/130/balance
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The provider offers APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com