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/payments/398` accepts POST requests and charges 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 catalog of pay-per-call endpoints spanning 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 listed endpoints are priced at $0.02 per request with no rate limits or minimum commitments.
However, the specific functionality behind `/api/v1/payments/398` is not documented beyond the label "Premium API Access." There is no OpenAPI schema, no request/response examples, and the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further detail. It is unclear what data or service this particular endpoint returns when a valid payment is submitted.
Capabilities
Use cases
- —Programmatic access to a premium API resource with per-call USDC micropayments
- —Agent-driven workflows that need keyless, pay-as-you-go API access on Base
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment flows
- —Agents that can settle USDC payments on Base L2
- —Use cases requiring no-signup, no-rate-limit API access
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —Anyone without a Base-compatible USDC wallet
- —Production workloads requiring well-documented request/response contracts
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/398 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge) and pricing is clear ($0.02 USDC on Base). However, there is no documentation of what the endpoint actually returns, no OpenAPI schema, no request/response examples, and the docs pages are empty beyond a wallet-connect prompt. The specific purpose of /api/v1/payments/398 is unknown.
Warnings
- —No documentation available — docs, pricing, and API pages all render only 'Connect wallet' with no content.
- —The specific functionality of /api/v1/payments/398 ('Premium API Access') is completely undocumented; it is unclear what data or service is returned upon payment.
- —No OpenAPI schema or request/response examples are provided.
- —The broader site lists many endpoints but none have documented schemas or sample payloads.
Citations
- —Endpoint returns HTTP 402 with x402 challenge requiring 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/payments/398
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/398
- —All endpoints priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com