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/transactions/152` 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 — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
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 uniformly priced at $0.02 per request.
This particular endpoint (`/api/v1/transactions/152`) is labeled "Premium API Access" but its actual functionality is unclear from the available documentation. The docs, API reference, pricing, and README pages all render only a "Connect wallet" prompt with no additional content. There is no OpenAPI schema, no request/response examples, and no description of what data this endpoint returns. Callers should be aware that the endpoint's behavior must be discovered empirically.
Capabilities
Use cases
- —Accessing premium data or transaction information via a single pay-per-call request
- —Integrating x402-compatible payment flows into agent workflows
- —Testing x402 protocol payment challenges on Base network
Fit
Best for
- —Developers experimenting with x402 micropayment protocols
- —Agents that need keyless, pay-as-you-go API access
- —Projects already operating on the Base L2 network with USDC
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or subscription plans
- —Anyone requiring non-USDC or non-Base-network payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/152 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no OpenAPI schema, no request/response examples, and no documentation beyond a landing page listing. The actual functionality of /api/v1/transactions/152 is undocumented, making this effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — endpoint behavior is unknown beyond the 402 challenge
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no useful content
- —The specific purpose of /api/v1/transactions/152 ('Premium API Access') is not explained anywhere
- —No request body schema or response schema is provided
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/152
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/152
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com