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/123`) is listed under "Premium API Access" and accepts POST requests. Payment is settled in USDC (contract `0x8335…2913` on Base) at a maximum cost of 20,000 base units, which equals $0.02 per request (USDC uses 6 decimals). No API keys, rate limits, or upfront commitments are required — callers simply attach an `X-PAYMENT` header with a valid x402 payment proof.
The broader lowpaymentfee.com platform advertises endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are priced uniformly at $0.02 per request.
Documentation is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/ach/123` endpoint actually returns. The endpoint is live (returns a valid 402 challenge), but the lack of documentation makes it difficult to determine the exact input parameters or output format.
Capabilities
Use cases
- —Programmatic ACH-related data retrieval with per-call USDC micropayments
- —Agent-driven API consumption without pre-registration or API key management
- —Integrating pay-as-you-go financial endpoints into automated workflows
Fit
Best for
- —Developers wanting zero-signup, pay-per-request API access
- —AI agents that can settle x402 payments on Base
- —Projects needing low-cost per-call pricing without rate limits
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who prefer subscription-based pricing
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/ach/123 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, documentation is essentially nonexistent — every doc/pricing/README page shows only 'Connect wallet'. There is no OpenAPI schema, no request/response examples, and no explanation of what '/api/v1/ach/123' actually does or accepts. The listing is effectively a stub.
Warnings
- —No documentation available — docs, pricing, API, and README pages all render only 'Connect wallet'
- —No OpenAPI or input/output schema provided; request parameters and response format are unknown
- —The specific purpose of /api/v1/ach/123 is unclear — 'Premium API Access' is a generic label
- —Cannot verify what data or service this endpoint actually provides
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/ach/123
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/ach/123
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com