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/payments/287` is labeled "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requesting up to 20,000 base units of USDC (0.02 USD given 6 decimals) per call, paid to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base. No API keys or rate limits are advertised — access is gated purely by the x402 payment header.
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 returns. The site's landing page lists many endpoints but provides no detail on request parameters or response formats. Without documentation it is unclear what data or functionality `/api/v1/payments/287` specifically provides versus the other listed endpoints.
Capabilities
Use cases
- —Programmatic access to premium API functionality paid per-call in USDC on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Exploring x402 payment protocol integration with minimal commitment
Fit
Best for
- —Developers experimenting with x402 payment-gated APIs
- —Agents that can settle USDC payments on Base automatically
- —Users who want no-signup, no-API-key access to utility endpoints
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/287 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing. However, there is no documentation, no OpenAPI spec, no request/response examples, and no explanation of what this specific endpoint actually does beyond the generic label 'Premium API Access'. The docs pages are empty. This is effectively a stub listing.
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/payments/287 is unclear; it does not match any of the named endpoints on the landing page
- —Cannot verify what data or service is actually returned after payment
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, 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/payments/287
- —Site lists APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only 'Connect wallet' with no contenthttps://lowpaymentfee.com/docs