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/payments/378` 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. No API keys or rate limits are required; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises multiple API categories including 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.
However, this specific endpoint (`/api/v1/payments/378`) has a generic "Premium API Access" description with no documentation on what it actually returns. The crawled docs, pricing, and API pages all rendered only a "Connect wallet" prompt with no further content. Without schema details, example responses, or documentation, the actual functionality behind this endpoint is unclear.
Capabilities
Use cases
- —Accessing premium API endpoints without traditional API key registration
- —Making micropayment-gated API calls using USDC on Base
- —Agent-driven workflows that need instant, keyless API access
Fit
Best for
- —Developers who want pay-as-you-go API access without subscriptions
- —AI agents that can settle x402 payments autonomously
- —Users already holding USDC on the Base network
Not for
- —Users who need detailed API documentation before integrating
- —Anyone requiring fiat-only payment methods
- —High-volume consumers who would benefit from bulk pricing
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/378 \
-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 it accepts USDC on Base at $0.02/request. However, there is no documentation, no OpenAPI schema, no example request/response, and the endpoint description is entirely generic ('Premium API Access'). The docs/pricing/API pages all render only 'Connect wallet' with no usable content.
Warnings
- —No documentation available — docs, pricing, and API pages all show only 'Connect wallet'
- —The specific functionality of /api/v1/payments/378 is completely undocumented
- —No OpenAPI schema or example responses provided
- —No input schema documented; unclear what POST body is expected
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/payments/378
- —The platform lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/requesthttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access advertisedhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/payments/378