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/27` is labeled "Premium API Access" and accepts POST requests, settling payments in USDC (USD Coin) on Base. The x402 challenge advertises a maximum amount of 20,000 base units of USDC (6 decimals), which 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 $0.02 per request with no API keys, no rate limits, and no minimum commitments.
The `/api/v1/collections/27` endpoint itself lacks detailed documentation — the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what "Premium API Access" actually returns. It may be a bundled or meta-endpoint covering the collection, but this is unconfirmed.
Capabilities
Use cases
- —Programmatic access to a suite of data, AI, finance, and utility APIs without managing API keys or subscriptions
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Prototyping integrations where per-request billing avoids upfront commitment
Fit
Best for
- —Developers or agents who want zero-friction, keyless API access
- —Use cases requiring small, infrequent API calls without subscription overhead
- —x402-compatible agents that can settle USDC payments on Base
Not for
- —High-volume production workloads where per-request pricing at $0.02 adds up quickly
- —Users who need detailed API documentation, SLAs, or guaranteed uptime
- —Anyone without a Base-compatible USDC wallet or x402 client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/27 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and no description of what 'Premium API Access' actually returns. The docs/pricing/API pages are all blank beyond a wallet-connect prompt.
Warnings
- —No documentation available — docs, pricing, and API pages only show 'Connect wallet' with no content
- —No OpenAPI or request/response schema provided for this endpoint
- —The purpose and output of '/api/v1/collections/27' ('Premium API Access') is undefined — it is unclear what data or functionality it provides
- —No robots.txt or agents.txt present
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/collections/27
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints in Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/collections/27