Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.
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 pay-per-request using USDC on the Base network, settled via the x402 protocol. There are no API keys, no rate limits, and no minimum commitments — callers simply attach an X-PAYMENT header with a valid x402 payment proof to access any endpoint.
The specific endpoint at `/api/v1/payments/97` is listed as "Premium API Access" and accepts POST requests. The x402 challenge indicates a maximum cost of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 per request (USDC uses 6 decimals). The broader platform advertises the same $0.02 flat rate across all its endpoints, covering categories like sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, and more.
Documentation is extremely sparse — 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 crawled material. The endpoint is confirmed live (returning a proper 402 challenge), but without documentation it is unclear what request body this specific endpoint expects or what response it returns.
Capabilities
Use cases
- —Accessing premium API services without managing API keys or subscriptions
- —Making one-off API calls with instant USDC micropayments on Base
- —Agent-driven workflows that need frictionless pay-per-use endpoints
Fit
Best for
- —Developers who want zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously
- —Users already holding USDC on the Base network
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume callers who would benefit from bulk pricing or subscriptions
- —Developers without access to USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/97 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and the landing page provides a clear pricing model. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The purpose of this specific '/payments/97' endpoint is unclear beyond the generic 'Premium API Access' label.
Warnings
- —No OpenAPI spec or schema documentation available
- —All documentation pages (/docs, /pricing, /api, /README) render only 'Connect wallet' with no content
- —The specific purpose and expected request body for /api/v1/payments/97 is undocumented
- —No response schema or example responses available
Citations
- —All endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The x402 challenge for /api/v1/payments/97 specifies maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/payments/97
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com