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/111` is listed under "Premium API Access" and accepts POST requests. Payment is made inline with each request via the X-PAYMENT header — no API keys, accounts, or rate limits are involved.
The x402 challenge confirms the endpoint is live, requiring up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The response MIME type is application/json.
The broader lowpaymentfee.com platform advertises endpoints across several categories — data/analytics, AI/ML (sentiment, summarization, classification, embeddings), finance/Web3 (price feeds, exchange rates, gas estimates), and infrastructure utilities (geocoding, validation, conversion). All are priced at $0.02 per request. However, documentation is extremely sparse: the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. The exact functionality of the `/api/v1/ach/111` endpoint is not documented beyond its title, so the actual request schema and response format remain unknown.
Capabilities
Use cases
- —Programmatic ACH-related data retrieval with per-call USDC payment
- —Agent-driven financial API access without pre-registration or API keys
- —Integrating pay-as-you-go endpoints into crypto-native workflows
Fit
Best for
- —Developers wanting zero-signup, pay-per-call API access
- —AI agents with x402-compatible payment capabilities on Base
- —Projects needing instant access without rate limits or commitments
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-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/ach/111 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is zero documentation for this specific endpoint — no request schema, no response examples, no explanation of what 'ach/111' actually returns. The docs, pricing, and README pages are all blank beyond a wallet-connect prompt.
Warnings
- —No documentation exists for /api/v1/ach/111 — the request body schema and response format are completely unknown.
- —All secondary pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no usable content.
- —The meaning of 'ACH' and '111' in the path is undocumented; it is unclear whether this relates to ACH bank transfers or something else.
- —No OpenAPI spec or machine-readable schema is available.
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base (= $0.02)https://lowpaymentfee.com/api/v1/ach/111
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/ach/111
- —Docs, API, pricing, and README pages all show only 'Connect wallet'https://lowpaymentfee.com/docs