Pay-per-call API platform on Base network 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 across data analytics, AI/ML inference, finance/Web3 data, and utility services. 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 subscription commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/30` is listed as "Premium API Access" and requires a maximum of 20,000 base units of USDC (i.e., $0.02) per call. The platform also advertises additional endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, gas estimates, geocoding, validation, conversion, and data export — all at the same $0.02 price point. Documentation pages (docs, pricing, README) appear to be behind a wallet-connect gate and provide no additional technical detail in the crawl.
Because there is no OpenAPI schema, no request/response examples, and no documentation beyond the landing page listing, the actual behavior of each endpoint is unclear. The endpoint is confirmed live (returns a proper 402 x402 challenge), but what data or functionality `/api/v1/transactions/30` specifically returns is not documented in any crawled material.
Capabilities
Use cases
- —Accessing AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto and finance data (token quotes, gas estimates, exchange rates) on a per-call basis
- —Running utility operations like geocoding, validation, and data conversion with micropayments
- —Integrating pay-per-use data analytics and export into agent workflows
Fit
Best for
- —Developers wanting zero-friction API access without signup or API keys
- —AI agents that can settle x402 payments in USDC on Base
- —Projects needing low-cost, pay-as-you-go access to diverse utility and data endpoints
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —Applications requiring high-throughput bulk access at volume-discounted pricing
- —Teams that cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/30 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, but there is no OpenAPI schema, no request/response examples, and documentation pages are gated behind wallet-connect with no useful content. The purpose of `/api/v1/transactions/30` specifically is undocumented. Pricing is clear ($0.02 USDC per call) but functional details are almost entirely absent.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —Documentation, pricing, and README pages are behind a wallet-connect gate and returned no useful content
- —The specific purpose and expected input/output of /api/v1/transactions/30 ('Premium API Access') is not documented anywhere in crawled material
- —The breadth of advertised endpoints (AI, finance, analytics, utilities) cannot be verified from available material
Citations
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The /api/v1/transactions/30 endpoint returns a 402 x402 challenge requiring 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/30
- —Platform advertises endpoints for analytics, AI/ML, finance/Web3, and infrastructure utilitieshttps://lowpaymentfee.com