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 broad catalog of pay-per-request 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, settled in USDC on the Base network.
The specific endpoint `/api/v1/charges/335` is labeled "Premium API Access" and returns a valid x402 402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) per call. Payment is made via the `exact` scheme to a specified wallet address. The endpoint accepts HTTP POST and returns `application/json`. No API keys or rate limits are advertised — access is gated entirely by the x402 micropayment.
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 spec, no request/response schema documentation, and no examples of what this particular endpoint actually returns. The site's landing page lists many endpoints but provides no detail on request parameters or response formats for any of them. Without documentation, it is unclear what data or functionality `/api/v1/charges/335` specifically provides beyond the generic "Premium API Access" label.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to undocumented premium services
Fit
Best for
- —Developers wanting keyless, pay-per-use API access
- —AI agents that can settle x402 payments on Base
- —Users comfortable with crypto micropayments for API calls
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —Applications requiring free or subscription-based access models
- —Developers who need non-crypto payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/335 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but documentation is essentially nonexistent — all doc/pricing/API pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and no description of what this specific endpoint actually does beyond the generic 'Premium API Access' label. Pricing is clear ($0.02/request) but the lack of any functional documentation makes this a near-stub listing.
Warnings
- —No documentation available — all doc pages render only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format
- —The specific functionality of /api/v1/charges/335 ('Premium API Access') is undefined
- —No examples of request or response payloads available
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 (0.02 USD) on Basehttps://lowpaymentfee.com/api/v1/charges/335
- —Site offers APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages all show only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs