Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API marketplace that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, paid in USDC on the Base network with no API keys, no rate limits, and no commitments required. The x402 payment protocol allows agents and clients to pay per call by attaching a payment header to each HTTP request.
The specific endpoint `/api/v1/wire/61` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts POST requests and returns application/json. However, the exact functionality behind this particular wire/61 endpoint is not documented — the site's landing page lists numerous categorized APIs (metrics, reports, sentiment analysis, summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, conversion, generation), but wire/61 does not map to any of those named endpoints.
Documentation is extremely thin: the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no examples available. The endpoint is live and responds correctly with an x402 challenge, but without knowing what wire/61 actually does, callers must experiment to discover its behavior.
Capabilities
Use cases
- —Programmatic pay-per-call access to API services without API key management
- —Agent-driven workflows that need on-demand API access settled in USDC on Base
- —Exploring x402 protocol integration for micropayment-gated endpoints
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-as-you-go API access
- —Users who want to avoid subscription commitments for occasional API calls
Not for
- —Users who need detailed API documentation before integrating
- —High-volume use cases where per-call pricing at $0.02 adds up significantly
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/wire/61 \
-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 the specific functionality of /api/v1/wire/61 is undocumented. No OpenAPI spec, no request/response schemas, no examples, and all documentation pages are empty beyond a wallet connect prompt. The listing is effectively a stub with confirmed liveness and pricing.
Warnings
- —The exact functionality of /api/v1/wire/61 ('Premium API Access') is not documented anywhere on the site
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no content
- —No OpenAPI spec or request/response schema is available
- —No examples of expected input or output for this endpoint
- —The wire/61 path does not correspond to any of the named API endpoints listed on the homepage
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/wire/61
- —Site lists APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com