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 at `/api/v1/transactions/239` is labeled "Premium API Access" and accepts POST requests. The platform advertises a flat $0.02 per request across all its endpoints, with no API keys, no rate limits, and instant access.
The site offers four broad categories of endpoints: 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 uniformly at $0.02 per call.
The probed endpoint returns a valid x402 challenge with `maxAmountRequired` of 20000 base units of USDC (0x8335… on Base), which equals $0.02 given USDC's 6 decimals. Payment is sent to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout. However, the specific functionality of the `/api/v1/transactions/239` endpoint is unclear — the description simply says "Premium API Access" without detailing what data or service it returns. Documentation pages (docs, pricing, README) all rendered only a "Connect wallet" prompt with no substantive content.
Capabilities
Use cases
- —Accessing premium API data with per-call USDC micropayments on Base
- —Agent-driven API consumption without API keys or subscriptions
- —Pay-as-you-go access to analytics, AI, finance, or utility endpoints
Fit
Best for
- —Developers wanting keyless, pay-per-request API access
- —AI agents that can settle x402 payments in USDC on Base
- —Users who prefer no-commitment, no-subscription API billing
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/239 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the specific purpose of the /api/v1/transactions/239 endpoint is undefined. All doc pages return only 'Connect wallet' with no content.
Warnings
- —The specific functionality of /api/v1/transactions/239 is undocumented — 'Premium API Access' is the only description available.
- —All documentation pages (/docs, /pricing, /README, /api) render only a 'Connect wallet' prompt with no substantive content.
- —No OpenAPI schema, request body schema, or response examples are available.
- —The endpoint path '/api/v1/transactions/239' with a numeric ID suggests a resource-specific route, but what resource '239' refers to is unknown.
Citations
- —Flat pricing of $0.02 per request across all endpointshttps://lowpaymentfee.com
- —No API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC on Base with 300s timeouthttps://lowpaymentfee.com/api/v1/transactions/239
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/239
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure endpoint categorieshttps://lowpaymentfee.com