Pay-per-call premium API access on Base via x402 — $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The specific resource `/api/v1/apikeys/16` appears to be one of many endpoints offered by the platform, which advertises a broad catalog spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per request.
Payment is settled on the Base network using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913). The x402 challenge confirms the endpoint is live and accepts POST requests with an exact payment scheme. The max amount required is 20,000 base units of USDC (6 decimals), which equals $0.02 USD per call. No API keys or rate limits are advertised; access is instant once the x402 payment header is provided.
The platform lists additional endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, conversion, and more — all at the same $0.02 price point. However, documentation beyond the landing page is essentially empty (all doc/pricing/API pages just show "Connect wallet"), so the actual behavior, input parameters, and response formats for this specific endpoint and others remain undocumented. The name "Premium API Access" and the path `/api/v1/apikeys/16` suggest this endpoint may generate or return an API key, but this is speculative given the lack of documentation.
Capabilities
Use cases
- —Acquiring API access or keys via a single micropayment
- —Agent-driven pay-per-call API consumption without pre-registration
- —Programmatic access to a multi-category API platform using crypto payments
Fit
Best for
- —Agents or developers wanting instant API access without signup
- —Micropayment-based API consumption on Base L2
- —x402-compatible clients looking for low-cost endpoints
Not for
- —Users needing detailed API documentation or schemas before purchasing
- —High-throughput use cases where $0.02/request adds up significantly
- —Users without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/16 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation of request/response formats, and the purpose of this specific endpoint (/api/v1/apikeys/16) is ambiguous. All documentation pages return only 'Connect wallet' with no actual content.
Warnings
- —No API documentation available — all doc pages are empty beyond 'Connect wallet'
- —The purpose of /api/v1/apikeys/16 is unclear; 'Premium API Access' is a generic label
- —No request or response schema is provided; input parameters are unknown
- —No examples of successful responses available
Citations
- —Platform lists APIs across data & analytics, AI & ML, finance & Web3, and infrastructure, all at $0.02/requesthttps://lowpaymentfee.com
- —Pricing is $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 USDC (=$0.02) on Base networkhttps://lowpaymentfee.com/api/v1/apikeys/16
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/apikeys/16