Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The specific resource at `/api/v1/charges/231` accepts POST requests and charges up to 20,000 base units of USDC (0x8335…2913) on the Base network, which equals $0.02 per request (USDC uses 6 decimals). Payment is handled inline via the X-PAYMENT header with no API keys or accounts required.
The broader lowpaymentfee.com platform advertises a suite of 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 $0.02 per request. However, the specific endpoint being listed here (`/api/v1/charges/231`) is labeled only as "Premium API Access" with no further documentation on what data or functionality it returns.
The endpoint is live and returns a valid x402 challenge (HTTP 402) with a 300-second payment timeout. No OpenAPI schema, request/response examples, or detailed documentation were found in the crawl — the docs, pricing, API, and README pages all rendered only a "Connect wallet" prompt with no substantive content. Because of this, the actual behavior and response format of this specific endpoint remain unknown.
Capabilities
Use cases
- —Programmatic access to a premium API resource without needing an API key or subscription
- —Agent-driven workflows that pay per call using USDC on Base
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment flows
- —Agents that need keyless, pay-as-you-go API access on Base
- —Low-volume consumers who want no commitments or rate limits
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —High-volume production workloads where per-request crypto payments add overhead
- —Anyone who needs to know the exact response schema before paying
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/231 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the actual functionality behind 'Premium API Access' at /api/v1/charges/231 is completely undocumented. All doc pages returned only a wallet-connect prompt.
Warnings
- —No documentation available — docs, pricing, API, and README pages all render only 'Connect wallet' with no content.
- —The specific functionality of /api/v1/charges/231 ('Premium API Access') is not described anywhere; it is unclear what this endpoint actually returns.
- —No OpenAPI spec or output schema beyond basic HTTP method metadata.
- —No request body schema or response examples available.
Citations
- —Endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/charges/231
- —All endpoints listed at $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
- —USDC contract address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/charges/231