x402-gated premium API access on Base, pay $0.02 per request in USDC — no API keys required.
What it does
lowpaymentfee.com offers a suite of pay-per-call API endpoints gated by the x402 protocol on the Base network. The specific endpoint at `/api/v1/charges/31` is labeled "Premium API Access" and returns a 402 challenge requesting payment in USDC (contract 0x8335…2913 on Base). The maximum amount required per call is 20,000 base units of USDC (6 decimals), which equals $0.02 USD. Payment is made via the x402 exact scheme by including an X-PAYMENT header with each request.
The broader lowpaymentfee.com platform advertises endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure (geocoding, validation, conversion, generation). All endpoints are listed at the same $0.02/request price point. The platform emphasizes no API keys, no rate limits, no minimums, and instant access.
However, the specific functionality behind `/api/v1/charges/31` ("Premium API Access") is not documented — it is unclear which of the above services this particular charge ID maps to, or whether it is a distinct endpoint. The docs, pricing, and API pages all returned only a "Connect wallet" prompt with no further documentation. There is no OpenAPI spec, no request/response schema, and no usage examples available from the crawl.
Capabilities
Use cases
- —Accessing premium API services with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API key management
- —Programmatic pay-as-you-go access to data, AI, finance, or utility endpoints
Fit
Best for
- —Developers or agents wanting keyless, pay-per-use API access
- —x402-compatible clients on the Base network
- —Low-volume or exploratory API usage at $0.02/call
Not for
- —Users who need detailed API documentation or guaranteed SLAs before purchasing
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Users without USDC on Base or an x402-compatible payment client
Quick start
# Send a POST with x402 payment header to access the endpoint
curl -X POST https://lowpaymentfee.com/api/v1/charges/31 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no documentation, no OpenAPI schema, no request/response examples, and the specific functionality of /api/v1/charges/31 is undefined. The docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —The specific functionality behind /api/v1/charges/31 ('Premium API Access') is not documented — it is unclear what data or service it provides.
- —No OpenAPI spec, request schema, or response schema is available.
- —All documentation pages (docs, pricing, API, README) returned only a 'Connect wallet' prompt with no usable content.
- —The platform lists many endpoint categories but none are individually documented with schemas or examples.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/31
- —USDC contract address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/31
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com