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 site hosts a collection of pay-per-request APIs spanning data & analytics, 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, settled in USDC on the Base network.
The specific endpoint `/api/v1/charges/65` is labeled "Premium API Access" and requires a payment of up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per call. Payment is made via the x402 exact scheme — no API keys, no rate limits, and no subscriptions are needed. The endpoint accepts POST requests and returns application/json responses.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the `/api/v1/charges/65` endpoint specifically returns. The site's landing page lists many API paths but does not clarify whether `/api/v1/charges/65` maps to one of them or is a separate resource. Prospective users should be aware that without documentation, the actual functionality behind this endpoint is unknown.
Capabilities
Use cases
- —Accessing paid API endpoints without subscriptions or API keys
- —Making micropayment-gated API calls settled in USDC on Base
- —Programmatic agent access to pay-per-use services via x402 protocol
Fit
Best for
- —Developers wanting zero-signup, pay-per-call API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —Applications requiring free or high-volume bulk access at discounted rates
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/65 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts payments. However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty beyond a wallet-connect prompt. The actual functionality of /api/v1/charges/65 is undocumented and unclear.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific functionality of /api/v1/charges/65 is not described anywhere
- —No examples of successful responses are available
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/charges/65
- —All listed APIs are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The site offers APIs across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/65