Pay-per-call premium API on Base via x402 — $0.02/request in USDC, no API keys required.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints settled via the x402 protocol on the Base network using USDC. The specific endpoint `/api/endpoint-98` is listed as "Premium API Access" and accepts POST requests. Payment is made per-call with no API keys, no rate limits, and no upfront commitments — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises 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 priced at $0.02 per request. The x402 challenge for this endpoint specifies a maxAmountRequired of 20000 base units of USDC (6 decimals), which equals $0.02.
Note that while the site lists many endpoints, the specific functionality behind `/api/endpoint-98` is not documented beyond the generic label "Premium API Access." There is no OpenAPI schema, no request/response examples, and the docs, pricing, and API pages all render only a "Connect wallet" prompt with no additional content. Prospective callers should be aware that the actual behavior of this endpoint is unclear from available documentation.
Capabilities
Use cases
- —Programmatic access to a premium API endpoint without needing API key registration
- —Agent-driven workflows that settle per-call costs in USDC on Base
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment flows
- —AI agents that need keyless, pay-as-you-go API access
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Anyone requiring non-crypto (fiat) payment methods
- —High-volume use cases where $0.02/request adds up without volume discounts
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-98 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, no documentation of what the endpoint actually does, and all doc pages render only 'Connect wallet'. The listing is effectively a stub with confirmed liveness.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —The specific functionality of /api/endpoint-98 ('Premium API Access') is completely undocumented
- —No OpenAPI or output schema provided beyond basic HTTP method info
- —No request or response examples available to verify endpoint behavior
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/endpoint-98
- —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 lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com