Pay-per-call premium API endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This endpoint at `/api/endpoint-21` is part of the lowpaymentfee.com platform, which offers a collection of pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities. All endpoints use the x402 payment protocol, settling in USDC on the Base network. The listed price is $0.02 per request with no API keys, no rate limits, and no minimum commitments required.
The specific function of `/api/endpoint-21` is unclear. The provider's landing page catalogs endpoints under paths like `/api/v1/analytics/`, `/api/v2/ai/`, `/api/v1/finance/`, `/api/v1/crypto/`, and `/api/v1/utils/`, but `/api/endpoint-21` does not appear among them. It may be an internal or unlisted endpoint. The x402 challenge confirms it is live, accepts POST requests, returns `application/json`, and requires a maximum payment of 20,000 base units of USDC (0.02 USDC, i.e., $0.02) on Base (asset contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`).
No OpenAPI schema, request/response examples, or detailed documentation were found for this specific endpoint. The docs, pricing, and API pages all rendered only a "Connect wallet" prompt with no additional content. Without knowing what this endpoint actually does, callers should treat it as an opaque premium API whose purpose must be discovered experimentally or confirmed with the provider.
Capabilities
Use cases
- —Agent-initiated pay-per-call API access without API keys
- —Programmatic micropayment-gated data retrieval on Base
- —Testing x402 payment protocol integrations
Fit
Best for
- —Developers exploring x402 payment-gated APIs
- —Agents that can settle USDC payments on Base L2
- —Low-cost per-request API consumption without subscriptions
Not for
- —Users who need detailed documentation or guaranteed SLAs before calling
- —Use cases requiring free or non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/endpoint-21 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but the specific function of /api/endpoint-21 is unknown—it does not appear in the provider's listed catalog. No schema, docs, or example responses are available, making this effectively a stub listing.
Warnings
- —The endpoint path /api/endpoint-21 does not match any documented endpoint on the provider's landing page; its actual functionality is unknown.
- —Documentation pages (/docs, /pricing, /api, /README) returned no useful content beyond a wallet-connect prompt.
- —No OpenAPI spec or output schema describing request/response formats was found.
Citations
- —The provider lists APIs at $0.02/request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge confirms the endpoint is live, accepts POST, returns application/json, and requires maxAmountRequired of 20000 base units of USDC on Base.https://lowpaymentfee.com/api/endpoint-21
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/endpoint-21