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/259` 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 listed at the same $0.02/request price point.
This particular endpoint (`/api/v1/transactions/259`) is labeled generically as "Premium API Access" and does not appear in the site's public API catalog, so its exact functionality is unclear. It accepts POST requests and returns application/json. The payment settles to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base. No OpenAPI schema, detailed documentation, or example responses were found during crawling — the docs, pricing, and API pages all render only a "Connect wallet" prompt.
Capabilities
Use cases
- —Making on-demand API calls without signing up for an account or managing API keys
- —Programmatic agents paying per-request with USDC on Base via x402
- —Accessing premium data or services with crypto micropayments
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who want bulk pricing or subscription discounts
- —Developers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/259 \
-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 the specific functionality of /api/v1/transactions/259 is undocumented. No OpenAPI schema, no example requests/responses, and all documentation pages render only a wallet-connect prompt. The listing is essentially a stub with verified liveness.
Warnings
- —The exact functionality of /api/v1/transactions/259 is unknown — it is not listed in the site's public API catalog
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no usable content
- —No OpenAPI spec, request schema, or response examples are available
- —The endpoint path includes a numeric ID (259) which may be ephemeral or user-specific
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC ($0.02) on Basehttps://lowpaymentfee.com/api/v1/transactions/259
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC contract address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/transactions/259
- —The site offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com