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. It is one of many endpoints on the platform, which offers a broad catalog of pay-per-request APIs spanning data & analytics, 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 endpoints are priced at $0.02 per request, settled in USDC on the Base network.
The specific endpoint `/api/v1/payments/73` is labeled "Premium API Access" but its exact functionality is not documented beyond that label. The x402 challenge confirms it is live, accepts POST requests, and requires a payment of up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is made via the x402 exact scheme with a 300-second timeout. No API keys or rate limits are advertised — access is gated purely by micropayment.
Documentation is extremely thin. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional content. There is no OpenAPI spec, no request/response schema, and no usage examples available from the crawled material. The platform's landing page lists the catalog and pricing but provides no detail on request formats or response payloads for any endpoint, including this one.
Capabilities
Use cases
- —Programmatic access to a pay-per-request API without needing API keys or subscriptions
- —Agent-driven workflows that settle per-call costs in USDC on Base
- —Testing x402 payment protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers exploring x402 micropayment-gated APIs
- —AI agents that need keyless, pay-as-you-go API access
- —Projects wanting to avoid subscription commitments for occasional API calls
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume use cases where per-request pricing at $0.02 may not be cost-effective
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/73 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming pricing and payment details. However, there is no documentation, no OpenAPI spec, no request/response schema, and no explanation of what 'Premium API Access' actually returns. The docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided for this or any endpoint on the platform
- —The specific functionality of /api/v1/payments/73 ('Premium API Access') is undefined — it is unclear what data or service it provides
- —The broader platform lists many endpoints but none have documented request formats or response payloads
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/payments/73
- —All endpoints on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs