Pay-per-call API platform on Base (USDC) via x402 — $0.02/request, no API keys required.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad set of endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. Every endpoint costs $0.02 per request, paid in USDC on the Base network. There are no API keys, no rate limits, and no subscription commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/customers/70` is listed as "Premium API Access" and returns `application/json` via POST. Its x402 challenge advertises a max amount of 20,000 base units of USDC (asset 0x8335…2913 on Base, 6 decimals), which equals $0.02. The platform also hosts endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point.
Documentation is extremely thin: the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawl. The endpoint is live (402 challenge confirmed), but the actual behavior and response format of `/api/v1/customers/70` is unclear from available materials.
Capabilities
Use cases
- —Accessing data analytics and reports without managing API keys or subscriptions
- —Running AI inference tasks (sentiment, summarization, classification, embeddings) on a per-call payment basis
- —Fetching real-time crypto/finance data (prices, exchange rates, gas estimates) with micropayments
- —Using utility endpoints (geocoding, validation, conversion) without rate limits
Fit
Best for
- —Developers who want instant API access without signup or key management
- —Agent-based workflows that can attach x402 payment headers automatically
- —Low-volume or bursty usage patterns where per-call pricing is more economical than subscriptions
Not for
- —High-volume production workloads where per-call costs would accumulate significantly
- —Users who need detailed API documentation, SDKs, or SLA guarantees before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/customers/70 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live with a valid x402 402 challenge and clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and the purpose of '/api/v1/customers/70' specifically is opaque. The docs/pricing/README pages are all empty wallet-connect stubs.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —The /docs, /pricing, /api, and /README pages contain no useful content — only a 'Connect wallet' prompt
- —The specific purpose and expected input/output of /api/v1/customers/70 ('Premium API Access') is undocumented and unclear
- —No request or response examples could be obtained
Citations
- —All endpoints cost $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 of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/customers/70
- —Platform offers endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs