Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints gated by the x402 payment protocol on the Base network. The specific endpoint `/api/v1/item/21` is listed as "Premium API Access" and returns a 402 challenge requiring payment in USDC (contract 0x8335…2913 on Base). The maximum amount required is 20,000 base units of USDC (6 decimals), which equals $0.02 per request. Payment is made via the x402 "exact" scheme with a 300-second timeout.
The broader lowpaymentfee.com platform advertises 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 listed at the same $0.02/request price point. The platform advertises no API keys, no rate limits, and instant access.
However, the specific `/api/v1/item/21` endpoint does not clearly map to any of the named endpoints on the landing page. There is no OpenAPI schema, no documentation beyond the landing page listing, and no example request/response bodies available. The docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no substantive content. Without documentation or schema details, it is unclear what input this endpoint expects or what it returns beyond a generic `application/json` MIME type.
Capabilities
Use cases
- —Accessing premium data or services with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Testing x402 payment protocol integrations against a live endpoint
Fit
Best for
- —Developers experimenting with x402 payment flows
- —Agents that need keyless, pay-as-you-go API access on Base
- —Low-volume consumers who want no subscription commitments
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-volume production workloads requiring rate-limit guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/item/21 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no documentation, no example requests or responses, and the endpoint path '/api/v1/item/21' does not correspond to any named service on the landing page. The docs/pricing/README pages are all empty beyond a wallet-connect prompt.
Warnings
- —No OpenAPI or schema documentation available for this endpoint
- —The path /api/v1/item/21 does not match any named endpoint on the provider's landing page — its actual functionality is unknown
- —All documentation pages (docs, pricing, README, api) returned only 'Connect wallet' with no content
- —No example request or response bodies could be determined
Citations
- —The endpoint returns a 402 challenge requiring 20000 base units of USDC on Base (=$0.02)https://lowpaymentfee.com/api/v1/item/21
- —The platform lists endpoints at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/item/21