Pay-per-call API key generation on Base via x402 — $0.02 per request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data & analytics, AI & machine learning, finance & Web3, and infrastructure utility categories. All endpoints are priced at $0.02 per request, settled in USDC on the Base network. No API keys, rate limits, or upfront commitments are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/apikeys/60` is listed as "Premium API Access." Based on the x402 challenge, it accepts POST requests and charges up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per call on the Base network. The payment is settled to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the exact payment scheme. The endpoint returns `application/json`.
The broader platform advertises additional endpoints including 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. However, documentation pages (docs, pricing, README) returned only a "Connect wallet" prompt with no substantive content, so the actual behavior and response schemas of these endpoints remain undocumented.
Capabilities
Use cases
- —Generating or accessing premium API keys via a single paid POST request
- —Agent-driven API consumption without pre-registration or API key management
- —Micropayment-gated access to utility and data endpoints
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously on Base
- —Projects needing low-cost per-request pricing without subscriptions
Not for
- —Users who need detailed API documentation or response schema guarantees before purchasing
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Developers not set up for USDC payments on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/60 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI schema, no documented request/response format, and all documentation pages are empty (showing only 'Connect wallet'). The purpose of the specific /api/v1/apikeys/60 endpoint is unclear beyond its title 'Premium API Access.'
Warnings
- —Documentation pages (/docs, /pricing, /README, /api) contain no substantive content — only a 'Connect wallet' prompt.
- —No request body schema or response schema is documented for this endpoint.
- —The exact functionality of /api/v1/apikeys/60 ('Premium API Access') is not explained anywhere in the crawled material.
- —The broader platform lists many endpoints (AI, finance, utils) but none have documented input/output schemas.
Citations
- —All endpoints priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/apikeys/60
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/apikeys/60
- —Platform offers endpoints across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com