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 utilities. All endpoints are priced at $0.02 per request, settled in USDC on the Base network. The platform requires no API keys, no rate limits, and no upfront commitments — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/apikeys/62` is listed as "Premium API Access" and returns a live 402 challenge requesting up to 20,000 base units of USDC (0.02 USDC, i.e. $0.02) on Base. The payment is made to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the exact payment scheme. The response MIME type is `application/json` and the endpoint accepts POST requests.
The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and data generation — all at the same $0.02 per-call price point. However, documentation beyond the landing page is extremely sparse; the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled content.
Capabilities
Use cases
- —Purchasing API access keys via micropayment without traditional subscription
- —Programmatic pay-per-use access to data, AI, finance, and utility endpoints
- —Agent-driven API consumption where each call is individually settled on-chain
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that need to autonomously purchase API calls with crypto
- —Projects already operating on the Base L2 network with USDC
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Developers without a Base-compatible wallet or USDC holdings
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/62 \
-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 it works. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page, and no examples. The purpose of the specific '/api/v1/apikeys/62' endpoint is unclear beyond the label 'Premium API Access'. Effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all docs/pricing/README pages return only 'Connect wallet'
- —The exact functionality of /api/v1/apikeys/62 is unclear; 'Premium API Access' is the only description
- —No request body schema or response schema documented anywhere in crawled content
- —Cannot verify what data or service is actually returned after payment
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The endpoint returns a 402 challenge requesting maxAmountRequired of 20000 base units of USDC (USD Coin) on Basehttps://lowpaymentfee.com/api/v1/apikeys/62
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs