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/charges/118` 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, the specific endpoint being listed here (`/api/v1/charges/118`) has a generic "Premium API Access" description with no documentation on what data or functionality it actually returns. The docs, pricing, and README pages on the site are effectively empty (showing only a "Connect wallet" prompt). Without further documentation or example responses, the actual behavior of this endpoint is unknown.
Capabilities
Use cases
- —Accessing a pay-per-call API endpoint without needing API key registration
- —Making micropayments in USDC on Base for API access
- —Agent-driven API consumption with x402 payment protocol
Fit
Best for
- —Developers wanting zero-signup API access via crypto micropayments
- —AI agents that can settle x402 payments autonomously
- —Users who prefer pay-as-you-go pricing with no commitments
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —Applications requiring free or fiat-only payment methods
- —Production workloads that need well-documented response schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/118 \
-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 on what this specific endpoint does, no input/output schema, no example requests or responses, and the site's docs pages are empty. The listing is essentially a stub with confirmed liveness but unknown functionality.
Warnings
- —No documentation available — docs, pricing, and README pages only show 'Connect wallet' with no content
- —The specific functionality of /api/v1/charges/118 ('Premium API Access') is completely undocumented
- —No input or output schema provided; callers cannot know what to send or expect back
- —The platform lists many API categories but it is unclear if they are all functional
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/charges/118
- —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/charges/118