Pay-per-request premium API access on Base via x402 — $0.02/call in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The site hosts a broad catalog of pay-per-call APIs spanning data & analytics, AI/ML inference (sentiment analysis, 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, payable in USDC on the Base network with no API keys, no rate limits, and no minimum commitments.
The specific endpoint `/api/v1/charges/145` is labeled "Premium API Access" and returns a standard x402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per call. Payment is settled on-chain to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the "exact" payment scheme. The endpoint accepts HTTP POST requests and returns `application/json` responses.
Note that while the landing page lists many API paths across multiple categories, the specific functionality behind `/api/v1/charges/145` is not documented beyond the generic "Premium API Access" label. 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. This makes it difficult to determine exactly what data or service this particular endpoint returns.
Capabilities
Use cases
- —Programmatic access to paid API services without traditional API key registration
- —Agent-driven workflows that need on-demand API calls settled in USDC on Base
- —Accessing data, analytics, AI, or utility endpoints with per-request crypto payments
Fit
Best for
- —Developers or agents who want keyless, pay-as-you-go API access
- —x402-compatible clients on the Base network
- —Low-friction micropayment API consumption at $0.02/request
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume use cases where per-request crypto settlement overhead matters
- —Users without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/145 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, and the landing page provides pricing and a catalog overview. However, no OpenAPI schema, request/response examples, or meaningful documentation exists for this specific endpoint. The docs/pricing/API pages are all behind a wallet-connect gate and yielded no content. The exact functionality of /api/v1/charges/145 is unclear.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —Docs, pricing, API, and README pages all render only 'Connect wallet' with no accessible content
- —The specific functionality behind /api/v1/charges/145 ('Premium API Access') is not described anywhere in the crawled material
- —Cannot verify what data or service is actually returned upon successful payment
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (USD Coin) on Base networkhttps://lowpaymentfee.com/api/v1/charges/145
- —Site lists APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —Payment address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using USDC contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/145