Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. All endpoints are pay-per-request at $0.02 each, settled in USDC on the Base network. No API keys, accounts, or rate limits are required — callers simply attach an x402 payment header to each request.
The specific endpoint at `/api/v1/transactions/143` is listed as "Premium API Access" and returns an x402 challenge requesting up to 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. The endpoint accepts POST requests and returns application/json. The broader platform advertises additional endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, conversion, and data export — all at the same $0.02 price point.
Documentation is extremely sparse. The /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what data any endpoint actually returns. The platform appears live (402 challenge is valid, root returns 200), but without documentation it is unclear what inputs the endpoints expect or what outputs they produce.
Capabilities
Use cases
- —Making one-off API calls without needing to register or manage API keys
- —Paying for AI inference (sentiment, summarization, classification, embeddings) per request via crypto
- —Fetching financial data like token quotes, gas estimates, or exchange rates on demand
- —Geocoding, validation, or data conversion utilities with no subscription commitment
Fit
Best for
- —Developers who want zero-signup, pay-as-you-go API access
- —Agents or bots that can attach x402 payment headers automatically
- —Users already holding USDC on Base who want frictionless micropayments
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible wallet or USDC holdings
Quick start
# POST with x402 payment header (pseudo-example)
curl -X POST https://lowpaymentfee.com/api/v1/transactions/143 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and pricing is clear ($0.02 USDC on Base), but there is zero documentation for any endpoint — no request schemas, no response examples, no OpenAPI spec. The /docs, /pricing, and /README pages are all empty beyond a wallet-connect prompt. The specific endpoint '/api/v1/transactions/143' has no description beyond its title. This is effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition found for any endpoint
- —No request or response examples available; it is unknown what data this endpoint accepts or returns
- —The endpoint path '/api/v1/transactions/143' with title 'Premium API Access' is vague — unclear what transaction 143 refers to
- —The broader platform lists many endpoint categories (AI, finance, analytics, etc.) but none have documented behavior
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/transactions/143
- —Platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /pricing, /api, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs