x402-gated account balance endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides a "Premium API Access" resource at `/api/v1/accounts/12/balance`, gated behind the x402 payment protocol. It returns a 402 challenge requiring payment in USDC on the Base network. The specific endpoint probed appears to return account balance information for account ID 12, though no detailed documentation or response schema is available beyond the x402 challenge itself.
The provider lowpaymentfee.com hosts a broader suite of x402-gated APIs spanning data & analytics, AI/ML (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 listed at $0.02 per request. The probed endpoint's maxAmountRequired of 20,000 base units of USDC (6 decimals) equals $0.02, consistent with the site's advertised pricing.
The platform advertises no API keys, no rate limits, and instant access — payment is handled entirely via the x402 protocol using USDC on Base. Documentation pages (/docs, /pricing, /api, /README) all resolve but contain only a "Connect wallet" prompt with no substantive technical documentation. There is no OpenAPI spec, no response schema, and no example responses available, making it difficult to know exactly what data this endpoint returns without making a paid request.
Capabilities
Use cases
- —Querying account balance data via a pay-per-call model without API key registration
- —Integrating x402-compatible agents that can autonomously pay for data access
- —Testing x402 protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-per-request API access on Base
- —Low-volume queries where $0.02/call is acceptable
Not for
- —High-volume balance lookups where per-call fees add up quickly
- —Users who need detailed API documentation or guaranteed SLAs
- —Anyone without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/12/balance
# Returns 402 with x402 challenge; include X-PAYMENT header with signed USDC payment to access.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no response schema, no example responses, and all documentation pages are empty stubs showing only 'Connect wallet'. The purpose of this specific endpoint (account 12 balance) is unclear and undocumented.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No response schema or example responses provided; unclear what data the endpoint actually returns
- —The endpoint path references a specific account ID (12) with no explanation of what accounts are available or what 'balance' means in this context
- —The broader site lists many API categories (AI, finance, analytics, infrastructure) but none have visible documentation
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/accounts/12/balance
- —The USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/accounts/12/balance
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The site hosts APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com