Pay-per-call ACH endpoint on Base via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints gated by the x402 protocol on the Base network. This specific endpoint (`/api/v1/ach/64`) is listed under the title "Premium API Access" but its exact functionality is not documented beyond that label. The site groups its APIs into categories including Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure utilities, all priced uniformly at $0.02 per request.
Payment is settled on-chain using USDC (contract `0x8335…2913`) on Base. The x402 challenge confirms the endpoint is live and accepts an `exact` payment scheme with a `maxAmountRequired` of 20,000 base units (USDC has 6 decimals, so this equals $0.02). No API keys, rate limits, or upfront commitments are advertised — callers simply attach an `X-PAYMENT` header with a valid x402 payment proof. The endpoint accepts HTTP POST and returns `application/json`.
Documentation is extremely sparse. The `/docs`, `/pricing`, `/api`, and `/README` pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema, and no description of what `/api/v1/ach/64` actually returns. The "ACH" path segment and "Premium API Access" title suggest it may relate to ACH (Automated Clearing House) payment processing data, but this is speculative. Prospective users should test the endpoint directly to determine its actual behavior.
Capabilities
Use cases
- —Accessing ACH-related data or services on a per-request basis without subscription
- —Integrating pay-per-call endpoints into agent workflows using x402 protocol
- —Testing x402 payment flows with a low-cost endpoint on Base
Fit
Best for
- —Developers experimenting with x402 protocol payments on Base
- —Agents needing on-demand API access without API key management
- —Low-volume or sporadic API consumers who prefer pay-per-use
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/ach/64 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_proof>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is zero documentation on what this endpoint actually does, no request/response schema, and no examples. The docs pages are empty. This is effectively a stub listing.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README all return only a wallet-connect prompt
- —No OpenAPI spec or request/response schema provided
- —The actual functionality of /api/v1/ach/64 is unknown; 'Premium API Access' is the only description
- —Cannot verify what data or service is returned without making a paid request
Citations
- —Endpoint returns 402 with x402 challenge accepting USDC on Base at maxAmountRequired 20000 base unitshttps://lowpaymentfee.com/api/v1/ach/64
- —All APIs priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/ach/64