Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/transactions/151` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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.
The specific functionality behind `/api/v1/transactions/151` is not documented beyond the label "Premium API Access." The docs, pricing, and API pages all resolve to a minimal "Connect wallet" prompt with no further technical documentation, OpenAPI schema, or example payloads. The endpoint accepts POST requests and returns `application/json`, but the request body schema and response structure are unknown.
Capabilities
Use cases
- —Paying per-call for API access without managing API keys or subscriptions
- —Programmatic agents purchasing data or compute on-demand via x402
- —Testing x402 payment flows against a live endpoint on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-as-you-go API access
- —Low-volume callers who want no subscription commitment
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —High-volume production workloads where per-request costs add up without bulk discounts
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/151 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no request/response examples, and the docs pages are empty stubs ('Connect wallet' only). The actual functionality behind 'Premium API Access' at /api/v1/transactions/151 is undocumented, making this effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet' with no content.
- —The specific functionality of /api/v1/transactions/151 ('Premium API Access') is completely undocumented; it is unclear what data or service it provides.
- —No OpenAPI schema or example request/response payloads are available.
- —The broader platform lists many endpoints (AI, analytics, finance, utils) but none have documented schemas or usage examples.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/151
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/151
- —Platform offers endpoints in Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com