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/transfers/193` is listed as "Premium API Access" and returns a 402 challenge requiring payment of 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 lowpaymentfee.com 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 priced at $0.02 per request.
This particular endpoint (`/api/v1/transfers/193`) is labeled "Premium API Access" but its actual functionality is not documented beyond that label. The crawled docs, pricing, API, and README pages all returned only a "Connect wallet" prompt with no further content. Without additional documentation or an OpenAPI schema, the specific input/output behavior of this endpoint remains unclear.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments
- —Agent-driven workflows that need keyless, on-demand API access
- —Programmatic pay-as-you-go API consumption without subscriptions
Fit
Best for
- —Developers who want to avoid API key management and subscriptions
- —AI agents that can settle x402 payments autonomously on Base
- —Low-volume or bursty workloads where per-call pricing is economical
Not for
- —High-volume use cases where $0.02/request adds up significantly
- —Users who need detailed API documentation or OpenAPI schemas before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/193 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no documentation beyond a label, and no examples of request/response payloads. The docs, pricing, API, and README pages are all empty stubs showing only 'Connect wallet'. The actual functionality behind 'Premium API Access' at /api/v1/transfers/193 is unknown.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The specific functionality of /api/v1/transfers/193 ('Premium API Access') is undocumented — the name alone does not clarify what it does
- —All documentation pages (docs, pricing, API, README) returned only 'Connect wallet' with no substantive content
- —The endpoint path includes a numeric ID (193) suggesting it may be a specific resource rather than a general-purpose API
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transfers/193
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transfers/193
- —Platform pricing is $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com