Pay-per-request API collection on Base via x402 — $0.02/call in USDC, no API keys required.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. The specific endpoint at `/api/v1/collections/36` is labeled "Premium API Access" and accepts POST requests, settling payments in USDC (contract 0x8335…2913 on Base). The x402 challenge advertises a maxAmountRequired of 20,000 base units, which at 6 decimals for USDC equals $0.02 per request.
The broader platform offers 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 utilities (geocoding, validation, conversion, generation). All endpoints are listed at the same $0.02/request price point.
The platform advertises no API keys, no rate limits, no minimums, and instant access. Payment is handled entirely through the x402 protocol's X-PAYMENT header mechanism on the Base L2 network. Documentation pages beyond the landing page appear to require wallet connection and were not crawlable, so detailed request/response schemas for this specific collection endpoint are unavailable.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without managing API keys or subscriptions
- —Fetching real-time financial data like token quotes, gas estimates, and exchange rates on a per-call basis
- —Running data analytics queries and exporting data with pay-as-you-go pricing
- —Using utility services like geocoding and validation from an agent that can settle x402 payments
Fit
Best for
- —AI agents that need on-demand access to diverse API endpoints via crypto micropayments
- —Developers who want to avoid API key management and subscription commitments
- —Applications on Base that need low-cost, per-request utility and data services
Not for
- —Users who need high-volume bulk access at discounted rates (flat $0.02/request with no volume tiers mentioned)
- —Applications that cannot settle payments in USDC on the Base network
- —Users who need detailed API documentation before integrating (docs pages require wallet connection and are sparse)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/36 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and documentation pages are gated behind wallet connection. The specific purpose of '/api/v1/collections/36' beyond 'Premium API Access' is unclear — it may be a bundle or a specific resource. This is effectively a stub listing.
Warnings
- —No OpenAPI or request/response schema available for this endpoint
- —Documentation, pricing, API, and README pages all return only 'Connect wallet' — no substantive docs crawlable
- —The specific function of /api/v1/collections/36 is unclear; 'Premium API Access' is a generic label
- —No rate limit or SLA information available
- —No information on what data or functionality this specific collection endpoint returns
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units in USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/collections/36
- —All endpoints are listed at $0.02 per request with no API keys, no rate limits, no minimumshttps://lowpaymentfee.com
- —Platform offers endpoints in Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC extra field identifies the asset as 'USD Coin' version 2https://lowpaymentfee.com/api/v1/collections/36