Pay-per-call ACH endpoint on Base via x402 — $0.02/request in USDC
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints settled via the x402 protocol on the Base network using USDC. This specific endpoint (`/api/v1/ach/18`) is listed under the title "Premium API Access." The site advertises a flat $0.02 per request across all its endpoints, with no API keys, no rate limits, and instant access.
The x402 challenge confirms the endpoint is live, accepting POST requests and requiring payment of up to 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this translates to $0.02 per call. Payment is made to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The response MIME type is application/json.
The exact functionality behind the `/api/v1/ach/18` path is unclear. The site groups its APIs into categories like Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure, but this particular ACH endpoint is not listed on the landing page among the advertised routes. No OpenAPI schema, detailed documentation, or example request/response payloads are available — the docs, pricing, and README pages all render only a "Connect wallet" prompt with no additional content. Without further documentation, the precise input parameters and output format of this endpoint remain unknown.
Capabilities
Use cases
- —Programmatic access to an ACH-related service with per-call USDC micropayments
- —Agent-driven workflows that need keyless, pay-as-you-go API access on Base
- —Integrating x402-compatible payment flows into automated pipelines
Fit
Best for
- —Developers experimenting with x402 pay-per-call protocols
- —Agents that can settle USDC payments on Base L2
- —Use cases requiring no-signup, no-rate-limit API access
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Applications requiring fiat or non-crypto payment methods
- —Anyone needing a well-documented, production-grade ACH processing API
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/ach/18 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no example requests or responses, and the specific functionality of /api/v1/ach/18 is undocumented even on the provider's own landing page. This is effectively a stub listing.
Warnings
- —The /api/v1/ach/18 endpoint is not listed among the advertised APIs on the provider's homepage — its purpose is unknown.
- —No API documentation is available; docs, pricing, and README pages only show a 'Connect wallet' prompt.
- —No OpenAPI schema or example payloads are provided, so input/output formats are entirely unknown.
- —The term 'ACH' in the path suggests possible financial/payment processing, which may involve regulatory considerations.
Citations
- —The site advertises $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02.https://lowpaymentfee.com/api/v1/ach/18
- —The endpoint is not listed among the advertised API routes on the landing page.https://lowpaymentfee.com