Check account balance via x402 micropayment on Base network for $0.02 per request.
What it does
This endpoint at lowpaymentfee.com returns account balance information for a specific account (account ID 187) behind an x402 paywall. It is part of a broader platform offering various pay-per-call APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services — all priced at $0.02 per request and settled in USDC on the Base network.
The endpoint accepts POST requests and returns JSON. Payment is handled via the x402 protocol: callers must include an X-PAYMENT header with a valid payment proof. The x402 challenge specifies an exact-scheme payment of up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimal places. No API keys or rate limits are advertised; access is gated purely by micropayment.
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 spec, no request/response schema documentation, and no usage examples available from the crawled material. The endpoint is confirmed live (returns a proper 402 challenge), but the actual response format and the meaning of the balance data are unknown.
Capabilities
Use cases
- —Querying account balance data programmatically with per-call USDC micropayments
- —Integrating balance lookups into agent workflows without managing API keys
- —Demonstrating x402 protocol payment flows on Base network
Fit
Best for
- —Developers experimenting with x402 micropayment protocols
- —Agents that need keyless, pay-per-call API access on Base
- —Quick one-off balance checks without subscription commitments
Not for
- —Production use cases requiring documented request/response schemas
- —High-volume balance monitoring where per-call fees add up
- —Users who need fiat payment options (only USDC on Base is accepted)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/187/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, but documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, no examples, and the purpose of this specific account balance endpoint is unclear. The listing is effectively a stub.
Warnings
- —No documentation available — all doc/pricing/API/README pages render only 'Connect wallet'
- —No OpenAPI or schema definition found for request or response payloads
- —The specific account ID (187) is hardcoded in the endpoint path; unclear if other account IDs are accessible
- —Purpose and data returned by the balance endpoint are entirely undocumented
Citations
- —The endpoint returns a 402 challenge with x402Version 1, exact scheme, on Base network, with maxAmountRequired of 20000 base units of USDChttps://lowpaymentfee.com/api/v1/accounts/187/balance
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 is USDC on Base (6 decimals), so 20000 base units = $0.02https://lowpaymentfee.com