Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com is one of many x402-gated API endpoints offered by the provider. The specific path `/api/v1/payments/38` is labeled "Premium API Access" and accepts POST requests, settling payments in USDC on the Base network. The x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (6 decimals), which equals $0.02 per request. No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform lists endpoints across four categories: 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 (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request. However, this specific listing covers only the `/api/v1/payments/38` path, whose exact functionality beyond "Premium API Access" is not documented.
The endpoint is live and returned a proper 402 challenge when probed. Documentation on the site is extremely thin — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema, and no usage examples available from the crawled material. The actual data or service returned by this particular endpoint after payment is unknown.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic access without subscription commitments or rate limits
Fit
Best for
- —Developers wanting zero-commitment, pay-per-use API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto micropayments over traditional API key subscriptions
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Anyone requiring non-crypto (fiat) payment methods
- —High-volume consumers who would benefit from bulk pricing or subscriptions
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/38 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and network. However, there is no documentation, no OpenAPI spec, no request/response examples, and the actual functionality behind 'Premium API Access' at this specific path is undocumented. The site's docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No OpenAPI spec or request/response schema available
- —Actual functionality of /api/v1/payments/38 is undocumented — 'Premium API Access' is the only label
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no technical content
- —No examples of successful responses are available
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/payments/38
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/payments/38