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/payments/103` is labeled "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02 given USDC's 6 decimals) 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 $0.02 per request. Payments settle on Base to the address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913).
Note that the crawled documentation pages (/docs, /pricing, /api, /README) all returned only a "Connect wallet" prompt with no substantive content, so the actual behavior and response schemas of the individual API endpoints remain undocumented. The endpoint is live (402 challenge confirmed), but without OpenAPI specs, example responses, or detailed docs, the exact capabilities behind each route cannot be independently verified.
Capabilities
Use cases
- —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key signup
- —Fetching real-time financial data like token quotes, gas estimates, and exchange rates on a per-call basis
- —Running data analytics queries and exporting data with per-request USDC micropayments
- —Using utility services like geocoding and validation without subscription commitments
Fit
Best for
- —Developers who want instant, keyless API access paid per request
- —Agents and bots that can settle USDC payments on Base via x402
- —Projects needing low-cost micropayment-gated API calls without rate limits
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Applications requiring high-throughput bulk access at volume-discounted pricing
- —Teams that cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/103 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no example request/response bodies, and all documentation pages return only a wallet-connect prompt. The actual behavior behind this and other listed endpoints is unverifiable from available material.
Warnings
- —No OpenAPI or schema documentation available for any endpoint
- —All doc pages (/docs, /pricing, /api, /README) returned only 'Connect wallet' with no content
- —Response format and actual functionality of /api/v1/payments/103 are unknown — 'Premium API Access' is the only description
- —The broader platform lists many endpoint categories but none could be independently verified
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/payments/103
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 and payTo is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3https://lowpaymentfee.com/api/v1/payments/103
- —Platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories all at $0.02/requesthttps://lowpaymentfee.com
- —Platform advertises no API keys, no rate limits, instant access, Base networkhttps://lowpaymentfee.com