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/277` 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 the same $0.02/request price point and settle in USDC on Base.
However, the specific endpoint probed (`/api/v1/transactions/277`) does not clearly map to any of the advertised API categories. Its description is simply "Premium API Access" with no further documentation on what data or functionality it returns. The docs, pricing, and README pages all rendered only a "Connect wallet" prompt with no substantive content. Without an OpenAPI schema, example responses, or detailed documentation, the actual behavior of this endpoint remains unclear.
Capabilities
Use cases
- —Accessing premium API data without traditional API key registration
- —Making one-off API calls paid per request in USDC on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
Fit
Best for
- —Developers who want to avoid API key management and subscriptions
- —AI agents that can autonomously pay for API calls via x402
- —Users already holding USDC on the Base network
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/277 \
-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 OpenAPI schema, no example responses, no documentation beyond a wallet-connect prompt, and the specific endpoint path (/api/v1/transactions/277) doesn't match any advertised API. The actual functionality is unknown.
Warnings
- —The endpoint path /api/v1/transactions/277 does not correspond to any of the documented API categories on the landing page.
- —All documentation pages (docs, pricing, README, api) render only 'Connect wallet' with no substantive content.
- —No OpenAPI schema or response examples are available — the actual data returned by this endpoint is unknown.
- —No information on uptime, SLAs, or rate limits beyond the marketing claim of 'no rate limits'.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base network.https://lowpaymentfee.com/api/v1/transactions/277
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access.https://lowpaymentfee.com
- —The USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base.https://lowpaymentfee.com/api/v1/transactions/277
- —API categories include Data & Analytics, AI & ML, Finance & Web3, and Infrastructure.https://lowpaymentfee.com