Pay-per-call premium API endpoint on Base via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 payment protocol on the Base network. This specific endpoint (`/api/endpoint-66`) is listed as "Premium API Access" and accepts USDC payments at a maximum cost of $0.02 per request (20,000 base units of USDC with 6 decimals). No API keys, rate limits, or upfront commitments are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform advertises endpoints across several 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 uniformly at $0.02 per request. However, this listing covers `/api/endpoint-66` specifically, which is described only as "Premium API Access" with no further documentation on what data or functionality it returns.
The endpoint is live and returns a well-formed x402 challenge (HTTP 402) with scheme "exact" on the Base network, paying to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` in USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The response MIME type is `application/json`. Documentation pages (`/docs`, `/pricing`, `/api`, `/README`) all returned only a "Connect wallet" prompt with no substantive content, so the actual request/response schema for this endpoint is unknown.
Capabilities
Use cases
- —Accessing a premium API resource with per-call USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to an undocumented premium endpoint
Fit
Best for
- —Developers or agents wanting zero-signup, pay-per-request API access
- —x402-compatible agents that can settle USDC on Base
- —Low-cost micropayment experimentation on the Base L2
Not for
- —Users who need detailed documentation or a known response schema before calling
- —High-volume use cases where $0.02/request adds up without bulk discounts
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-66 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what /api/endpoint-66 actually does, what inputs it expects, or what it returns. The docs, pricing, API, and README pages are all empty (just 'Connect wallet'). The listing is effectively a stub with confirmed liveness but no usable schema or examples.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all return only 'Connect wallet' with no content.
- —The purpose and functionality of /api/endpoint-66 ('Premium API Access') is completely undocumented; it is unclear what this endpoint does or what data it returns.
- —No OpenAPI spec, input schema, or output schema is provided beyond the basic x402 outputSchema stub.
- —The endpoint path '/api/endpoint-66' does not match any of the documented API paths on the landing page (which use /api/v1/ and /api/v2/ prefixes), raising questions about what this endpoint actually serves.
Citations
- —Endpoint returns HTTP 402 with x402 challenge on POST, confirming it is livehttps://lowpaymentfee.com/api/endpoint-66
- —Max amount required is 20000 base units of USDC (6 decimals = $0.02) on Base networkhttps://lowpaymentfee.com/api/endpoint-66
- —All listed endpoints are priced at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/endpoint-66
- —Documentation pages (/docs, /pricing, /api, /README) contain only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs