x402-gated premium API endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at `/api/v1/ach/168` is part of the lowpaymentfee.com platform, which offers a collection of x402-protocol pay-per-request APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. The specific endpoint `/api/v1/ach/168` is labeled "Premium API Access" but its exact functionality is not documented — the path segment `ach/168` suggests it may relate to ACH (Automated Clearing House) payment processing or financial data, but this is speculative.
The endpoint is live and returns a valid x402 challenge. Payment is settled on the Base network using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The maximum amount required is 20,000 base units of USDC, which with 6 decimals equals $0.02 per request. The platform advertises flat $0.02/request pricing across all endpoints with no API keys, no rate limits, and instant access.
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 this specific endpoint accepts or returns beyond the generic "Premium API Access" label and `application/json` MIME type. The input schema indicates it accepts HTTP POST requests.
Capabilities
Use cases
- —Accessing a pay-per-call API endpoint without API key registration
- —Making programmatic financial or ACH-related queries via x402 protocol
- —Integrating micropayment-gated services into agent workflows
Fit
Best for
- —Developers wanting zero-signup API access via crypto micropayments
- —AI agents that can settle x402 payments on Base
- —Users needing low-cost per-request API calls without subscriptions
Not for
- —Users who need detailed API documentation before integrating
- —Applications requiring high-throughput with guaranteed SLAs
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/ach/168 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what this specific endpoint does, what inputs it expects, or what it returns. The 'ach/168' path and 'Premium API Access' label are the only clues. No OpenAPI spec, no examples, no docs content beyond 'Connect wallet'.
Warnings
- —Endpoint functionality is completely undocumented — the purpose of /api/v1/ach/168 is unknown
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no useful content
- —No request or response schema available
- —The 'ach' path segment may imply regulated financial services (ACH payments) — verify compliance before use
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/ach/168
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/ach/168