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/45` is listed as "Premium API Access" and returns a 402 challenge requiring payment of 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 priced at $0.02 per request.
The specific functionality behind `/api/v1/transactions/45` is not documented beyond the label "Premium API Access." The crawled docs, pricing, API, and README pages all rendered only a "Connect wallet" prompt with no additional content, so the actual request/response schemas and detailed behavior of this endpoint remain unknown. Callers should expect a POST method with JSON mime type based on the x402 challenge metadata.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments on Base
- —Integrating pay-as-you-go API calls into agent workflows without API key management
- —Making one-off API requests without subscription commitments
Fit
Best for
- —Developers who want keyless, pay-per-use API access
- —AI agents with x402-compatible wallets on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or OpenAPI schemas before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Users without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/45 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the actual functionality behind 'Premium API Access' at /api/v1/transactions/45 is completely undocumented. All doc pages returned only 'Connect wallet' with no content.
Warnings
- —The actual functionality of /api/v1/transactions/45 is undocumented — 'Premium API Access' is the only description available.
- —No OpenAPI spec, request schema, or response schema is provided.
- —All documentation pages (docs, pricing, API, README) render only 'Connect wallet' with no useful content.
- —The endpoint path '/api/v1/transactions/45' suggests a resource-specific route (transaction ID 45) but no context is given for what this represents.
Citations
- —The endpoint returns a 402 challenge requiring up to 20,000 base units of USDC ($0.02) on Base networkhttps://lowpaymentfee.com/api/v1/transactions/45
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/45