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 settled via the x402 protocol on the Base network using USDC. The specific endpoint at `/api/v1/ach/11` is listed as "Premium API Access" and accepts POST requests. Payment is made per-call with no API keys, no rate limits, and no upfront commitments.
The x402 challenge confirms the endpoint is live, accepting USDC (contract `0x8335…2913` on Base) with a `maxAmountRequired` of 20,000 base units. Since USDC uses 6 decimals, this translates to $0.02 per request, consistent with the site's advertised flat pricing of $0.02/request across all endpoints. The payment scheme is "exact" with a 300-second timeout.
The broader lowpaymentfee.com platform advertises endpoints spanning data & analytics, AI/ML (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). However, the specific functionality behind `/api/v1/ach/11` is not documented beyond the generic "Premium API Access" label. No OpenAPI schema, request/response examples, or detailed documentation were found — the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further content.
Capabilities
Use cases
- —Programmatic access to ACH-related data or operations at $0.02 per call
- —Agent-driven workflows that need keyless, pay-as-you-go API access on Base
- —Integrating low-cost per-request endpoints without subscription overhead
Fit
Best for
- —Developers wanting zero-setup, pay-per-use API access
- —AI agents that can settle x402 payments in USDC on Base
- —Projects needing low-cost API calls without rate limits or API key management
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Applications requiring non-crypto payment methods
- —High-volume batch processing where per-request pricing may add up
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/ach/11 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the actual functionality of /api/v1/ach/11 is completely undocumented. The endpoint name 'Premium API Access' is generic and uninformative.
Warnings
- —The specific functionality of /api/v1/ach/11 is entirely undocumented — 'Premium API Access' provides no indication of what the endpoint actually does.
- —No OpenAPI spec, request schema, or response schema is available.
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no usable content.
- —The 'ach' path segment suggests ACH (Automated Clearing House) banking functionality, but this is unconfirmed and could be misleading.
Citations
- —Flat pricing of $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units in USDC on Base with exact scheme and 300s timeouthttps://lowpaymentfee.com/api/v1/ach/11
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/ach/11