Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/transfers/22` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) per call. The platform advertises no API keys, no rate limits, and instant access — you simply attach an x402 payment header to each request.
The broader platform offers 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 utilities (geocoding, validation, conversion, generation). All endpoints are listed at the same $0.02/request price point.
However, documentation 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 documentation, and no example payloads available. The specific functionality of the `/api/v1/transfers/22` endpoint (labeled "Premium API Access") is unclear — it does not appear in the homepage's listed API catalog, and its purpose cannot be determined from the available material.
Capabilities
Use cases
- —Accessing pay-per-request API endpoints without needing API keys or subscriptions
- —Making micropayment-gated HTTP calls settled in USDC on Base
- —Integrating agent-purchasable endpoints into automated workflows
Fit
Best for
- —Developers wanting zero-commitment, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto-native micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume use cases where per-request pricing may add up compared to bulk plans
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/22 \
-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 it accepts USDC on Base at $0.02/request. However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the specific purpose of /api/v1/transfers/22 is undocumented and absent from the site's own API catalog. This is effectively a stub listing.
Warnings
- —The endpoint /api/v1/transfers/22 does not appear in the provider's own listed API catalog — its specific functionality is unknown.
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no technical content.
- —No OpenAPI spec, no request/response examples, and no schema documentation available.
- —The purpose and expected input/output of this endpoint cannot be determined from available material.
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base network.https://lowpaymentfee.com/api/v1/transfers/22
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories, all at $0.02/request.https://lowpaymentfee.com
- —The platform advertises no API keys, no rate limits, instant access, and Base network settlement.https://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base network.https://lowpaymentfee.com/api/v1/transfers/22