Pay-per-call ACH endpoint on Base via x402 — $0.02/request in USDC, no API keys required.
What it does
This endpoint at `/api/v1/ach/51` is part of the lowpaymentfee.com platform, which offers a collection of pay-per-request APIs spanning data analytics, AI/ML inference, finance, crypto, and utility services. All endpoints use the x402 payment protocol, settling in USDC on the Base network. The specific function of the `/api/v1/ach/51` path is not documented — the provider labels it generically as "Premium API Access" — so the exact data or service it returns is unclear. It may relate to ACH (Automated Clearing House) banking data or routing information given the URL path, but this is speculative.
Pricing is $0.02 per request (20,000 base units of USDC with 6 decimals = $0.02). There are no API keys, no rate limits, and no subscription commitments — callers simply attach an x402 payment header with each request. The endpoint accepts POST requests and returns `application/json`. The x402 challenge was successfully captured with version 1, confirming the endpoint is live. Payment is sent to `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base, with a 300-second timeout.
The broader platform lists roughly 16 endpoints across categories like sentiment analysis, text summarization, embeddings, price feeds, gas estimates, geocoding, and more — all at the same $0.02 price point. Documentation beyond the landing page is essentially empty (all sub-pages just show "Connect wallet"), so there is no schema documentation, example requests, or response format details available for any endpoint.
Capabilities
Use cases
- —Accessing ACH-related data or routing information on a per-call basis
- —Agent-driven workflows needing keyless, pay-as-you-go API access
- —Programmatic access to financial infrastructure without subscription overhead
Fit
Best for
- —Developers wanting zero-setup API access with crypto micropayments
- —AI agents that can settle x402 payments autonomously on Base
- —Users who need occasional API calls without committing to a subscription
Not for
- —Users needing detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or rate-limited tiers
- —Anyone requiring fiat-only payment rails
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/ach/51 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but the specific functionality of /api/v1/ach/51 is undocumented. No request/response schemas, no examples, and all documentation pages are empty stubs showing only 'Connect wallet'. The purpose of this particular endpoint can only be guessed from the URL path.
Warnings
- —The exact functionality of /api/v1/ach/51 is not documented anywhere — 'Premium API Access' is a generic label applied without specifics.
- —All documentation pages (/docs, /api, /pricing, /README) are empty, showing only 'Connect wallet'.
- —No request or response schema is available; callers have no way to know what parameters to send or what data to expect.
- —The 'ach' in the URL path suggests ACH banking data but this is unconfirmed speculation.
Citations
- —Endpoint returns 402 with x402 challenge, confirming it is live on Base with USDChttps://lowpaymentfee.com/api/v1/ach/51
- —Pricing is $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers ~16 endpoints across data/analytics, AI/ML, finance/web3, and infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/ach/51